File indexing completed on 2024-05-19 16:34:34

 /*
     KWin - the KDE window manager
     This file is part of the KDE project.
 
     SPDX-FileCopyrightText: 2006-2007 Rivo Laks <rivolaks@hot.ee>
     SPDX-FileCopyrightText: 2010, 2011 Martin Gräßlin <mgraesslin@kde.org>
 
     SPDX-License-Identifier: GPL-2.0-or-later
 */
 
 #include "kwinglutils.h"
 
 // need to call GLTexturePrivate::initStatic()
 #include "kwingltexture_p.h"
 
 #include "kwineffects.h"
 #include "kwinglplatform.h"
 #include "logging_p.h"
 
 #include <QFile>
 #include <QHash>
 #include <QImage>
 #include <QMatrix4x4>
 #include <QPixmap>
 #include <QVarLengthArray>
 #include <QVector2D>
 #include <QVector3D>
 #include <QVector4D>
 
 #include <array>
 #include <cmath>
 #include <deque>
 
 #define DEBUG_GLFRAMEBUFFER 0
 
 #ifdef __GNUC__
 #define likely(x) __builtin_expect(!!(x), 1)
 #define unlikely(x) __builtin_expect(!!(x), 0)
 #else
 #define likely(x) (x)
 #define unlikely(x) (x)
 #endif
 
 namespace KWin
 {
 // Variables
 // List of all supported GL extensions
 static QList<QByteArray> glExtensions;
 
 // Functions
 
 static void initDebugOutput()
 {
     static bool enabled = qEnvironmentVariableIntValue("KWIN_GL_DEBUG");
     if (!enabled) {
         return;
     }
 
     const bool have_KHR_debug = hasGLExtension(QByteArrayLiteral("GL_KHR_debug"));
     const bool have_ARB_debug = hasGLExtension(QByteArrayLiteral("GL_ARB_debug_output"));
     if (!have_KHR_debug && !have_ARB_debug) {
         return;
     }
 
     if (!have_ARB_debug) {
         // if we don't have ARB debug, but only KHR debug we need to verify whether the context is a debug context
         // it should work without as well, but empirical tests show: no it doesn't
         if (GLPlatform::instance()->isGLES()) {
             if (!hasGLVersion(3, 2)) {
                 // empirical data shows extension doesn't work
                 return;
             }
         } else if (!hasGLVersion(3, 0)) {
             return;
         }
         // can only be queried with either OpenGL >= 3.0 or OpenGL ES of at least 3.1
         GLint value = 0;
         glGetIntegerv(GL_CONTEXT_FLAGS, &value);
         if (!(value & GL_CONTEXT_FLAG_DEBUG_BIT)) {
             return;
         }
     }
 
     // Set the callback function
     auto callback = [](GLenum source, GLenum type, GLuint id,
                        GLenum severity, GLsizei length,
                        const GLchar *message,
                        const GLvoid *userParam) {
         while (length && std::isspace(message[length - 1])) {
             --length;
         }
 
         switch (type) {
         case GL_DEBUG_TYPE_ERROR:
         case GL_DEBUG_TYPE_UNDEFINED_BEHAVIOR:
             qCWarning(LIBKWINGLUTILS, "%#x: %.*s", id, length, message);
             break;
 
         case GL_DEBUG_TYPE_OTHER:
         case GL_DEBUG_TYPE_DEPRECATED_BEHAVIOR:
         case GL_DEBUG_TYPE_PORTABILITY:
         case GL_DEBUG_TYPE_PERFORMANCE:
         default:
             qCDebug(LIBKWINGLUTILS, "%#x: %.*s", id, length, message);
             break;
         }
     };
 
     glDebugMessageCallback(callback, nullptr);
 
     // This state exists only in GL_KHR_debug
     if (have_KHR_debug) {
         glEnable(GL_DEBUG_OUTPUT);
     }
 
 #if !defined(QT_NO_DEBUG)
     // Enable all debug messages
     glDebugMessageControl(GL_DONT_CARE, GL_DONT_CARE, GL_DONT_CARE, 0, nullptr, GL_TRUE);
 #else
     // Enable error messages
     glDebugMessageControl(GL_DONT_CARE, GL_DEBUG_TYPE_ERROR, GL_DONT_CARE, 0, nullptr, GL_TRUE);
     glDebugMessageControl(GL_DONT_CARE, GL_DEBUG_TYPE_UNDEFINED_BEHAVIOR, GL_DONT_CARE, 0, nullptr, GL_TRUE);
 #endif
 
     // Insert a test message
     const QByteArray message = QByteArrayLiteral("OpenGL debug output initialized");
     glDebugMessageInsert(GL_DEBUG_SOURCE_APPLICATION, GL_DEBUG_TYPE_OTHER, 0,
                          GL_DEBUG_SEVERITY_LOW, message.length(), message.constData());
 }
 
 void initGL(const std::function<resolveFuncPtr(const char *)> &resolveFunction)
 {
     // Get list of supported OpenGL extensions
     if (hasGLVersion(3, 0)) {
         int count;
         glGetIntegerv(GL_NUM_EXTENSIONS, &count);
 
         for (int i = 0; i < count; i++) {
             const QByteArray name = (const char *)glGetStringi(GL_EXTENSIONS, i);
             glExtensions << name;
         }
     } else {
         glExtensions = QByteArray((const char *)glGetString(GL_EXTENSIONS)).split(' ');
     }
 
     // handle OpenGL extensions functions
     glResolveFunctions(resolveFunction);
 
     initDebugOutput();
 
     GLTexturePrivate::initStatic();
     GLFramebuffer::initStatic();
     GLVertexBuffer::initStatic();
 }
 
 void cleanupGL()
 {
     ShaderManager::cleanup();
     GLTexturePrivate::cleanup();
     GLFramebuffer::cleanup();
     GLVertexBuffer::cleanup();
     GLPlatform::cleanup();
 
     glExtensions.clear();
 }
 
 bool hasGLVersion(int major, int minor, int release)
 {
     return GLPlatform::instance()->glVersion() >= kVersionNumber(major, minor, release);
 }
 
 bool hasGLExtension(const QByteArray &extension)
 {
     return glExtensions.contains(extension);
 }
 
 QList<QByteArray> openGLExtensions()
 {
     return glExtensions;
 }
 
 static QString formatGLError(GLenum err)
 {
     switch (err) {
     case GL_NO_ERROR:
         return QStringLiteral("GL_NO_ERROR");
     case GL_INVALID_ENUM:
         return QStringLiteral("GL_INVALID_ENUM");
     case GL_INVALID_VALUE:
         return QStringLiteral("GL_INVALID_VALUE");
     case GL_INVALID_OPERATION:
         return QStringLiteral("GL_INVALID_OPERATION");
     case GL_STACK_OVERFLOW:
         return QStringLiteral("GL_STACK_OVERFLOW");
     case GL_STACK_UNDERFLOW:
         return QStringLiteral("GL_STACK_UNDERFLOW");
     case GL_OUT_OF_MEMORY:
         return QStringLiteral("GL_OUT_OF_MEMORY");
     default:
         return QLatin1String("0x") + QString::number(err, 16);
     }
 }
 
 bool checkGLError(const char *txt)
 {
     GLenum err = glGetError();
     if (err == GL_CONTEXT_LOST) {
         qCWarning(LIBKWINGLUTILS) << "GL error: context lost";
         return true;
     }
     bool hasError = false;
     while (err != GL_NO_ERROR) {
         qCWarning(LIBKWINGLUTILS) << "GL error (" << txt << "): " << formatGLError(err);
         hasError = true;
         err = glGetError();
         if (err == GL_CONTEXT_LOST) {
             qCWarning(LIBKWINGLUTILS) << "GL error: context lost";
             break;
         }
     }
     return hasError;
 }
 
 //****************************************
 // GLShader
 //****************************************
 
 GLShader::GLShader(unsigned int flags)
     : mValid(false)
     , mLocationsResolved(false)
     , mExplicitLinking(flags & ExplicitLinking)
 {
     mProgram = glCreateProgram();
 }
 
 GLShader::GLShader(const QString &vertexfile, const QString &fragmentfile, unsigned int flags)
     : mValid(false)
     , mLocationsResolved(false)
     , mExplicitLinking(flags & ExplicitLinking)
 {
     mProgram = glCreateProgram();
     loadFromFiles(vertexfile, fragmentfile);
 }
 
 GLShader::~GLShader()
 {
     if (mProgram) {
         glDeleteProgram(mProgram);
     }
 }
 
 bool GLShader::loadFromFiles(const QString &vertexFile, const QString &fragmentFile)
 {
     QFile vf(vertexFile);
     if (!vf.open(QIODevice::ReadOnly)) {
         qCCritical(LIBKWINGLUTILS) << "Couldn't open" << vertexFile << "for reading!";
         return false;
     }
     const QByteArray vertexSource = vf.readAll();
 
     QFile ff(fragmentFile);
     if (!ff.open(QIODevice::ReadOnly)) {
         qCCritical(LIBKWINGLUTILS) << "Couldn't open" << fragmentFile << "for reading!";
         return false;
     }
     const QByteArray fragmentSource = ff.readAll();
 
     return load(vertexSource, fragmentSource);
 }
 
 bool GLShader::link()
 {
     // Be optimistic
     mValid = true;
 
     glLinkProgram(mProgram);
 
     // Get the program info log
     int maxLength, length;
     glGetProgramiv(mProgram, GL_INFO_LOG_LENGTH, &maxLength);
 
     QByteArray log(maxLength, 0);
     glGetProgramInfoLog(mProgram, maxLength, &length, log.data());
 
     // Make sure the program linked successfully
     int status;
     glGetProgramiv(mProgram, GL_LINK_STATUS, &status);
 
     if (status == 0) {
         qCCritical(LIBKWINGLUTILS) << "Failed to link shader:"
                                    << "\n"
                                    << log;
         mValid = false;
     } else if (length > 0) {
         qCDebug(LIBKWINGLUTILS) << "Shader link log:" << log;
     }
 
     return mValid;
 }
 
 const QByteArray GLShader::prepareSource(GLenum shaderType, const QByteArray &source) const
 {
     // Prepare the source code
     QByteArray ba;
     if (GLPlatform::instance()->isGLES() && GLPlatform::instance()->glslVersion() < kVersionNumber(3, 0)) {
         ba.append("precision highp float;\n");
     }
     ba.append(source);
     if (GLPlatform::instance()->isGLES() && GLPlatform::instance()->glslVersion() >= kVersionNumber(3, 0)) {
         ba.replace("#version 140", "#version 300 es\n\nprecision highp float;\n");
     }
 
     return ba;
 }
 
 bool GLShader::compile(GLuint program, GLenum shaderType, const QByteArray &source) const
 {
     GLuint shader = glCreateShader(shaderType);
 
     QByteArray preparedSource = prepareSource(shaderType, source);
     const char *src = preparedSource.constData();
     glShaderSource(shader, 1, &src, nullptr);
 
     // Compile the shader
     glCompileShader(shader);
 
     // Get the shader info log
     int maxLength, length;
     glGetShaderiv(shader, GL_INFO_LOG_LENGTH, &maxLength);
 
     QByteArray log(maxLength, 0);
     glGetShaderInfoLog(shader, maxLength, &length, log.data());
 
     // Check the status
     int status;
     glGetShaderiv(shader, GL_COMPILE_STATUS, &status);
 
     if (status == 0) {
         const char *typeName = (shaderType == GL_VERTEX_SHADER ? "vertex" : "fragment");
         qCCritical(LIBKWINGLUTILS) << "Failed to compile" << typeName << "shader:"
                                    << "\n"
                                    << log;
     } else if (length > 0) {
         qCDebug(LIBKWINGLUTILS) << "Shader compile log:" << log;
     }
 
     if (status != 0) {
         glAttachShader(program, shader);
     }
 
     glDeleteShader(shader);
     return status != 0;
 }
 
 bool GLShader::load(const QByteArray &vertexSource, const QByteArray &fragmentSource)
 {
     // Make sure shaders are actually supported
     if (!(GLPlatform::instance()->supports(GLSL) &&
           // we lack shader branching for Texture2DRectangle everywhere - and it's probably not worth it
           GLPlatform::instance()->supports(TextureNPOT))) {
         qCCritical(LIBKWINGLUTILS) << "Shaders are not supported";
         return false;
     }
 
     mValid = false;
 
     // Compile the vertex shader
     if (!vertexSource.isEmpty()) {
         bool success = compile(mProgram, GL_VERTEX_SHADER, vertexSource);
 
         if (!success) {
             return false;
         }
     }
 
     // Compile the fragment shader
     if (!fragmentSource.isEmpty()) {
         bool success = compile(mProgram, GL_FRAGMENT_SHADER, fragmentSource);
 
         if (!success) {
             return false;
         }
     }
 
     if (mExplicitLinking) {
         return true;
     }
 
     // link() sets mValid
     return link();
 }
 
 void GLShader::bindAttributeLocation(const char *name, int index)
 {
     glBindAttribLocation(mProgram, index, name);
 }
 
 void GLShader::bindFragDataLocation(const char *name, int index)
 {
     if (!GLPlatform::instance()->isGLES() && (hasGLVersion(3, 0) || hasGLExtension(QByteArrayLiteral("GL_EXT_gpu_shader4")))) {
         glBindFragDataLocation(mProgram, index, name);
     }
 }
 
 void GLShader::bind()
 {
     glUseProgram(mProgram);
 }
 
 void GLShader::unbind()
 {
     glUseProgram(0);
 }
 
 void GLShader::resolveLocations()
 {
     if (mLocationsResolved) {
         return;
     }
 
     mMatrixLocation[TextureMatrix] = uniformLocation("textureMatrix");
     mMatrixLocation[ProjectionMatrix] = uniformLocation("projection");
     mMatrixLocation[ModelViewMatrix] = uniformLocation("modelview");
     mMatrixLocation[ModelViewProjectionMatrix] = uniformLocation("modelViewProjectionMatrix");
     mMatrixLocation[WindowTransformation] = uniformLocation("windowTransformation");
     mMatrixLocation[ScreenTransformation] = uniformLocation("screenTransformation");
 
     mVec2Location[Offset] = uniformLocation("offset");
 
     mVec4Location[ModulationConstant] = uniformLocation("modulation");
 
     mFloatLocation[Saturation] = uniformLocation("saturation");
 
     mColorLocation[Color] = uniformLocation("geometryColor");
 
     mIntLocation[TextureWidth] = uniformLocation("textureWidth");
     mIntLocation[TextureHeight] = uniformLocation("textureHeight");
 
     mLocationsResolved = true;
 }
 
 int GLShader::uniformLocation(const char *name)
 {
     const int location = glGetUniformLocation(mProgram, name);
     return location;
 }
 
 bool GLShader::setUniform(GLShader::MatrixUniform uniform, const QMatrix4x4 &matrix)
 {
     resolveLocations();
     return setUniform(mMatrixLocation[uniform], matrix);
 }
 
 bool GLShader::setUniform(GLShader::Vec2Uniform uniform, const QVector2D &value)
 {
     resolveLocations();
     return setUniform(mVec2Location[uniform], value);
 }
 
 bool GLShader::setUniform(GLShader::Vec4Uniform uniform, const QVector4D &value)
 {
     resolveLocations();
     return setUniform(mVec4Location[uniform], value);
 }
 
 bool GLShader::setUniform(GLShader::FloatUniform uniform, float value)
 {
     resolveLocations();
     return setUniform(mFloatLocation[uniform], value);
 }
 
 bool GLShader::setUniform(GLShader::IntUniform uniform, int value)
 {
     resolveLocations();
     return setUniform(mIntLocation[uniform], value);
 }
 
 bool GLShader::setUniform(GLShader::ColorUniform uniform, const QVector4D &value)
 {
     resolveLocations();
     return setUniform(mColorLocation[uniform], value);
 }
 
 bool GLShader::setUniform(GLShader::ColorUniform uniform, const QColor &value)
 {
     resolveLocations();
     return setUniform(mColorLocation[uniform], value);
 }
 
 bool GLShader::setUniform(const char *name, float value)
 {
     const int location = uniformLocation(name);
     return setUniform(location, value);
 }
 
 bool GLShader::setUniform(const char *name, int value)
 {
     const int location = uniformLocation(name);
     return setUniform(location, value);
 }
 
 bool GLShader::setUniform(const char *name, const QVector2D &value)
 {
     const int location = uniformLocation(name);
     return setUniform(location, value);
 }
 
 bool GLShader::setUniform(const char *name, const QVector3D &value)
 {
     const int location = uniformLocation(name);
     return setUniform(location, value);
 }
 
 bool GLShader::setUniform(const char *name, const QVector4D &value)
 {
     const int location = uniformLocation(name);
     return setUniform(location, value);
 }
 
 bool GLShader::setUniform(const char *name, const QMatrix4x4 &value)
 {
     const int location = uniformLocation(name);
     return setUniform(location, value);
 }
 
 bool GLShader::setUniform(const char *name, const QColor &color)
 {
     const int location = uniformLocation(name);
     return setUniform(location, color);
 }
 
 bool GLShader::setUniform(int location, float value)
 {
     if (location >= 0) {
         glUniform1f(location, value);
     }
     return (location >= 0);
 }
 
 bool GLShader::setUniform(int location, int value)
 {
     if (location >= 0) {
         glUniform1i(location, value);
     }
     return (location >= 0);
 }
 
 bool GLShader::setUniform(int location, const QVector2D &value)
 {
     if (location >= 0) {
         glUniform2fv(location, 1, (const GLfloat *)&value);
     }
     return (location >= 0);
 }
 
 bool GLShader::setUniform(int location, const QVector3D &value)
 {
     if (location >= 0) {
         glUniform3fv(location, 1, (const GLfloat *)&value);
     }
     return (location >= 0);
 }
 
 bool GLShader::setUniform(int location, const QVector4D &value)
 {
     if (location >= 0) {
         glUniform4fv(location, 1, (const GLfloat *)&value);
     }
     return (location >= 0);
 }
 
 bool GLShader::setUniform(int location, const QMatrix4x4 &value)
 {
     if (location >= 0) {
         glUniformMatrix4fv(location, 1, GL_FALSE, value.constData());
     }
     return (location >= 0);
 }
 
 bool GLShader::setUniform(int location, const QColor &color)
 {
     if (location >= 0) {
         glUniform4f(location, color.redF(), color.greenF(), color.blueF(), color.alphaF());
     }
     return (location >= 0);
 }
 
 int GLShader::attributeLocation(const char *name)
 {
     int location = glGetAttribLocation(mProgram, name);
     return location;
 }
 
 bool GLShader::setAttribute(const char *name, float value)
 {
     int location = attributeLocation(name);
     if (location >= 0) {
         glVertexAttrib1f(location, value);
     }
     return (location >= 0);
 }
 
 QMatrix4x4 GLShader::getUniformMatrix4x4(const char *name)
 {
     int location = uniformLocation(name);
     if (location >= 0) {
         GLfloat m[16];
         glGetnUniformfv(mProgram, location, sizeof(m), m);
         QMatrix4x4 matrix(m[0], m[4], m[8], m[12],
                           m[1], m[5], m[9], m[13],
                           m[2], m[6], m[10], m[14],
                           m[3], m[7], m[11], m[15]);
         matrix.optimize();
         return matrix;
     } else {
         return QMatrix4x4();
     }
 }
 
 //****************************************
 // ShaderManager
 //****************************************
 std::unique_ptr<ShaderManager> ShaderManager::s_shaderManager;
 
 ShaderManager *ShaderManager::instance()
 {
     if (!s_shaderManager) {
         s_shaderManager.reset(new ShaderManager());
     }
     return s_shaderManager.get();
 }
 
 void ShaderManager::cleanup()
 {
     s_shaderManager.reset();
 }
 
 ShaderManager::ShaderManager()
 {
 }
 
 ShaderManager::~ShaderManager()
 {
     while (!m_boundShaders.isEmpty()) {
         popShader();
     }
 }
 
 QByteArray ShaderManager::generateVertexSource(ShaderTraits traits) const
 {
     QByteArray source;
     QTextStream stream(&source);
 
     GLPlatform *const gl = GLPlatform::instance();
     QByteArray attribute, varying;
 
     if (!gl->isGLES()) {
         const bool glsl_140 = gl->glslVersion() >= kVersionNumber(1, 40);
 
         attribute = glsl_140 ? QByteArrayLiteral("in") : QByteArrayLiteral("attribute");
         varying = glsl_140 ? QByteArrayLiteral("out") : QByteArrayLiteral("varying");
 
         if (glsl_140) {
             stream << "#version 140\n\n";
         }
     } else {
         const bool glsl_es_300 = gl->glslVersion() >= kVersionNumber(3, 0);
 
         attribute = glsl_es_300 ? QByteArrayLiteral("in") : QByteArrayLiteral("attribute");
         varying = glsl_es_300 ? QByteArrayLiteral("out") : QByteArrayLiteral("varying");
 
         if (glsl_es_300) {
             stream << "#version 300 es\n\n";
         }
     }
 
     stream << attribute << " vec4 position;\n";
     if (traits & ShaderTrait::MapTexture) {
         stream << attribute << " vec4 texcoord;\n\n";
         stream << varying << " vec2 texcoord0;\n\n";
     } else {
         stream << "\n";
     }
 
     stream << "uniform mat4 modelViewProjectionMatrix;\n\n";
 
     stream << "void main()\n{\n";
     if (traits & ShaderTrait::MapTexture) {
         stream << "    texcoord0 = texcoord.st;\n";
     }
 
     stream << "    gl_Position = modelViewProjectionMatrix * position;\n";
     stream << "}\n";
 
     stream.flush();
     return source;
 }
 
 QByteArray ShaderManager::generateFragmentSource(ShaderTraits traits) const
 {
     QByteArray source;
     QTextStream stream(&source);
 
     GLPlatform *const gl = GLPlatform::instance();
     QByteArray varying, output, textureLookup;
 
     if (!gl->isGLES()) {
         const bool glsl_140 = gl->glslVersion() >= kVersionNumber(1, 40);
 
         if (glsl_140) {
             stream << "#version 140\n\n";
         }
 
         varying = glsl_140 ? QByteArrayLiteral("in") : QByteArrayLiteral("varying");
         textureLookup = glsl_140 ? QByteArrayLiteral("texture") : QByteArrayLiteral("texture2D");
         output = glsl_140 ? QByteArrayLiteral("fragColor") : QByteArrayLiteral("gl_FragColor");
     } else {
         const bool glsl_es_300 = GLPlatform::instance()->glslVersion() >= kVersionNumber(3, 0);
 
         if (glsl_es_300) {
             stream << "#version 300 es\n\n";
         }
 
         // From the GLSL ES specification:
         //
         //     "The fragment language has no default precision qualifier for floating point types."
         stream << "precision highp float;\n\n";
 
         varying = glsl_es_300 ? QByteArrayLiteral("in") : QByteArrayLiteral("varying");
         textureLookup = glsl_es_300 ? QByteArrayLiteral("texture") : QByteArrayLiteral("texture2D");
         output = glsl_es_300 ? QByteArrayLiteral("fragColor") : QByteArrayLiteral("gl_FragColor");
     }
 
     if (traits & ShaderTrait::MapTexture) {
         stream << "uniform sampler2D sampler;\n";
 
         if (traits & ShaderTrait::Modulate) {
             stream << "uniform vec4 modulation;\n";
         }
         if (traits & ShaderTrait::AdjustSaturation) {
             stream << "uniform float saturation;\n";
         }
 
         stream << "\n"
                << varying << " vec2 texcoord0;\n";
 
     } else if (traits & ShaderTrait::UniformColor) {
         stream << "uniform vec4 geometryColor;\n";
     }
 
     if (output != QByteArrayLiteral("gl_FragColor")) {
         stream << "\nout vec4 " << output << ";\n";
     }
 
     stream << "\nvoid main(void)\n{\n";
     if (traits & ShaderTrait::MapTexture) {
         stream << "vec2 texcoordC = texcoord0;\n";
 
         if (traits & (ShaderTrait::Modulate | ShaderTrait::AdjustSaturation)) {
             stream << "    vec4 texel = " << textureLookup << "(sampler, texcoordC);\n";
             if (traits & ShaderTrait::Modulate) {
                 stream << "    texel *= modulation;\n";
             }
             if (traits & ShaderTrait::AdjustSaturation) {
                 stream << "    texel.rgb = mix(vec3(dot(texel.rgb, vec3(0.2126, 0.7152, 0.0722))), texel.rgb, saturation);\n";
             }
 
             stream << "    " << output << " = texel;\n";
         } else {
             stream << "    " << output << " = " << textureLookup << "(sampler, texcoordC);\n";
         }
     } else if (traits & ShaderTrait::UniformColor) {
         stream << "    " << output << " = geometryColor;\n";
     }
 
     stream << "}";
     stream.flush();
     return source;
 }
 
 std::unique_ptr<GLShader> ShaderManager::generateShader(ShaderTraits traits)
 {
     return generateCustomShader(traits);
 }
 
 std::unique_ptr<GLShader> ShaderManager::generateCustomShader(ShaderTraits traits, const QByteArray &vertexSource, const QByteArray &fragmentSource)
 {
     const QByteArray vertex = vertexSource.isEmpty() ? generateVertexSource(traits) : vertexSource;
     const QByteArray fragment = fragmentSource.isEmpty() ? generateFragmentSource(traits) : fragmentSource;
 
 #if 0
     qCDebug(LIBKWINGLUTILS) << "**************";
     qCDebug(LIBKWINGLUTILS) << vertex;
     qCDebug(LIBKWINGLUTILS) << "**************";
     qCDebug(LIBKWINGLUTILS) << fragment;
     qCDebug(LIBKWINGLUTILS) << "**************";
 #endif
 
     std::unique_ptr<GLShader> shader{new GLShader(GLShader::ExplicitLinking)};
     shader->load(vertex, fragment);
 
     shader->bindAttributeLocation("position", VA_Position);
     shader->bindAttributeLocation("texcoord", VA_TexCoord);
     shader->bindFragDataLocation("fragColor", 0);
 
     shader->link();
     return shader;
 }
 
 static QString resolveShaderFilePath(const QString &filePath)
 {
     QString suffix;
     QString extension;
 
     const qint64 coreVersionNumber = GLPlatform::instance()->isGLES() ? kVersionNumber(3, 0) : kVersionNumber(1, 40);
     if (GLPlatform::instance()->glslVersion() >= coreVersionNumber) {
         suffix = QStringLiteral("_core");
     }
 
     if (filePath.endsWith(QStringLiteral(".frag"))) {
         extension = QStringLiteral(".frag");
     } else if (filePath.endsWith(QStringLiteral(".vert"))) {
         extension = QStringLiteral(".vert");
     } else {
         qCWarning(LIBKWINGLUTILS) << filePath << "must end either with .vert or .frag";
         return QString();
     }
 
     const QString prefix = filePath.chopped(extension.size());
     return prefix + suffix + extension;
 }
 
 std::unique_ptr<GLShader> ShaderManager::generateShaderFromFile(ShaderTraits traits, const QString &vertexFile, const QString &fragmentFile)
 {
     auto loadShaderFile = [](const QString &filePath) {
         QFile file(filePath);
         if (file.open(QIODevice::ReadOnly)) {
             return file.readAll();
         }
         qCCritical(LIBKWINGLUTILS) << "Failed to read shader " << filePath;
         return QByteArray();
     };
     QByteArray vertexSource;
     QByteArray fragmentSource;
     if (!vertexFile.isEmpty()) {
         vertexSource = loadShaderFile(resolveShaderFilePath(vertexFile));
         if (vertexSource.isEmpty()) {
             return std::unique_ptr<GLShader>(new GLShader());
         }
     }
     if (!fragmentFile.isEmpty()) {
         fragmentSource = loadShaderFile(resolveShaderFilePath(fragmentFile));
         if (fragmentSource.isEmpty()) {
             return std::unique_ptr<GLShader>(new GLShader());
         }
     }
     return generateCustomShader(traits, vertexSource, fragmentSource);
 }
 
 GLShader *ShaderManager::shader(ShaderTraits traits)
 {
     std::unique_ptr<GLShader> &shader = m_shaderHash[traits];
     if (!shader) {
         shader = generateShader(traits);
     }
     return shader.get();
 }
 
 GLShader *ShaderManager::getBoundShader() const
 {
     if (m_boundShaders.isEmpty()) {
         return nullptr;
     } else {
         return m_boundShaders.top();
     }
 }
 
 bool ShaderManager::isShaderBound() const
 {
     return !m_boundShaders.isEmpty();
 }
 
 GLShader *ShaderManager::pushShader(ShaderTraits traits)
 {
     GLShader *shader = this->shader(traits);
     pushShader(shader);
     return shader;
 }
 
 void ShaderManager::pushShader(GLShader *shader)
 {
     // only bind shader if it is not already bound
     if (shader != getBoundShader()) {
         shader->bind();
     }
     m_boundShaders.push(shader);
 }
 
 void ShaderManager::popShader()
 {
     if (m_boundShaders.isEmpty()) {
         return;
     }
     GLShader *shader = m_boundShaders.pop();
     if (m_boundShaders.isEmpty()) {
         // no more shader bound - unbind
         shader->unbind();
     } else if (shader != m_boundShaders.top()) {
         // only rebind if a different shader is on top of stack
         m_boundShaders.top()->bind();
     }
 }
 
 void ShaderManager::bindFragDataLocations(GLShader *shader)
 {
     shader->bindFragDataLocation("fragColor", 0);
 }
 
 void ShaderManager::bindAttributeLocations(GLShader *shader) const
 {
     shader->bindAttributeLocation("vertex", VA_Position);
     shader->bindAttributeLocation("texCoord", VA_TexCoord);
 }
 
 std::unique_ptr<GLShader> ShaderManager::loadShaderFromCode(const QByteArray &vertexSource, const QByteArray &fragmentSource)
 {
     std::unique_ptr<GLShader> shader{new GLShader(GLShader::ExplicitLinking)};
     shader->load(vertexSource, fragmentSource);
     bindAttributeLocations(shader.get());
     bindFragDataLocations(shader.get());
     shader->link();
     return shader;
 }
 
 /***  GLFramebuffer  ***/
 bool GLFramebuffer::sSupported = false;
 bool GLFramebuffer::s_blitSupported = false;
 QStack<GLFramebuffer *> GLFramebuffer::s_fbos = QStack<GLFramebuffer *>();
 
 void GLFramebuffer::initStatic()
 {
     if (GLPlatform::instance()->isGLES()) {
         sSupported = true;
         s_blitSupported = hasGLVersion(3, 0);
     } else {
         sSupported = hasGLVersion(3, 0) || hasGLExtension(QByteArrayLiteral("GL_ARB_framebuffer_object")) || hasGLExtension(QByteArrayLiteral("GL_EXT_framebuffer_object"));
 
         s_blitSupported = hasGLVersion(3, 0) || hasGLExtension(QByteArrayLiteral("GL_ARB_framebuffer_object")) || hasGLExtension(QByteArrayLiteral("GL_EXT_framebuffer_blit"));
     }
 }
 
 void GLFramebuffer::cleanup()
 {
     Q_ASSERT(s_fbos.isEmpty());
     sSupported = false;
     s_blitSupported = false;
 }
 
 bool GLFramebuffer::blitSupported()
 {
     return s_blitSupported;
 }
 
 GLFramebuffer *GLFramebuffer::currentFramebuffer()
 {
     return s_fbos.isEmpty() ? nullptr : s_fbos.top();
 }
 
 void GLFramebuffer::pushFramebuffer(GLFramebuffer *fbo)
 {
     fbo->bind();
     s_fbos.push(fbo);
 }
 
 void GLFramebuffer::pushFramebuffers(QStack<GLFramebuffer *> fbos)
 {
     fbos.top()->bind();
     s_fbos.append(fbos);
 }
 
 GLFramebuffer *GLFramebuffer::popFramebuffer()
 {
     GLFramebuffer *ret = s_fbos.pop();
     if (!s_fbos.isEmpty()) {
         s_fbos.top()->bind();
     } else {
         glBindFramebuffer(GL_FRAMEBUFFER, 0);
     }
 
     return ret;
 }
 
 GLFramebuffer::GLFramebuffer()
 {
 }
 
 GLFramebuffer::GLFramebuffer(GLTexture *colorAttachment)
     : mSize(colorAttachment->size())
 {
     // Make sure FBO is supported
     if (sSupported && !colorAttachment->isNull()) {
         initFBO(colorAttachment);
     } else {
         qCCritical(LIBKWINGLUTILS) << "Framebuffer objects aren't supported!";
     }
 }
 
 GLFramebuffer::GLFramebuffer(GLuint handle, const QSize &size)
     : mFramebuffer(handle)
     , mSize(size)
     , mValid(true)
     , mForeign(true)
 {
 }
 
 GLFramebuffer::~GLFramebuffer()
 {
     if (!mForeign && mValid) {
         glDeleteFramebuffers(1, &mFramebuffer);
     }
 }
 
 bool GLFramebuffer::bind()
 {
     if (!valid()) {
         qCCritical(LIBKWINGLUTILS) << "Can't enable invalid framebuffer object!";
         return false;
     }
 
     glBindFramebuffer(GL_FRAMEBUFFER, handle());
     glViewport(0, 0, mSize.width(), mSize.height());
 
     return true;
 }
 
 static QString formatFramebufferStatus(GLenum status)
 {
     switch (status) {
     case GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT:
         // An attachment is the wrong type / is invalid / has 0 width or height
         return QStringLiteral("GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT");
     case GL_FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT:
         // There are no images attached to the framebuffer
         return QStringLiteral("GL_FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT");
     case GL_FRAMEBUFFER_UNSUPPORTED:
         // A format or the combination of formats of the attachments is unsupported
         return QStringLiteral("GL_FRAMEBUFFER_UNSUPPORTED");
     case GL_FRAMEBUFFER_INCOMPLETE_DIMENSIONS_EXT:
         // Not all attached images have the same width and height
         return QStringLiteral("GL_FRAMEBUFFER_INCOMPLETE_DIMENSIONS_EXT");
     case GL_FRAMEBUFFER_INCOMPLETE_FORMATS_EXT:
         // The color attachments don't have the same format
         return QStringLiteral("GL_FRAMEBUFFER_INCOMPLETE_FORMATS_EXT");
     case GL_FRAMEBUFFER_INCOMPLETE_MULTISAMPLE_EXT:
         // The attachments don't have the same number of samples
         return QStringLiteral("GL_FRAMEBUFFER_INCOMPLETE_MULTISAMPLE");
     case GL_FRAMEBUFFER_INCOMPLETE_DRAW_BUFFER_EXT:
         // The draw buffer is missing
         return QStringLiteral("GL_FRAMEBUFFER_INCOMPLETE_DRAW_BUFFER");
     case GL_FRAMEBUFFER_INCOMPLETE_READ_BUFFER_EXT:
         // The read buffer is missing
         return QStringLiteral("GL_FRAMEBUFFER_INCOMPLETE_READ_BUFFER");
     default:
         return QStringLiteral("Unknown (0x") + QString::number(status, 16) + QStringLiteral(")");
     }
 }
 
 void GLFramebuffer::initFBO(GLTexture *colorAttachment)
 {
 #if DEBUG_GLFRAMEBUFFER
     GLenum err = glGetError();
     if (err != GL_NO_ERROR)
         qCCritical(LIBKWINGLUTILS) << "Error status when entering GLFramebuffer::initFBO: " << formatGLError(err);
 #endif
 
     GLuint prevFbo = 0;
     if (const GLFramebuffer *current = currentFramebuffer()) {
         prevFbo = current->handle();
     }
 
     glGenFramebuffers(1, &mFramebuffer);
 
 #if DEBUG_GLFRAMEBUFFER
     if ((err = glGetError()) != GL_NO_ERROR) {
         qCCritical(LIBKWINGLUTILS) << "glGenFramebuffers failed: " << formatGLError(err);
         return;
     }
 #endif
 
     glBindFramebuffer(GL_FRAMEBUFFER, mFramebuffer);
 
 #if DEBUG_GLFRAMEBUFFER
     if ((err = glGetError()) != GL_NO_ERROR) {
         qCCritical(LIBKWINGLUTILS) << "glBindFramebuffer failed: " << formatGLError(err);
         glDeleteFramebuffers(1, &mFramebuffer);
         return;
     }
 #endif
 
     glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
                            colorAttachment->target(), colorAttachment->texture(), 0);
 
 #if DEBUG_GLFRAMEBUFFER
     if ((err = glGetError()) != GL_NO_ERROR) {
         qCCritical(LIBKWINGLUTILS) << "glFramebufferTexture2D failed: " << formatGLError(err);
         glBindFramebuffer(GL_FRAMEBUFFER, prevFbo);
         glDeleteFramebuffers(1, &mFramebuffer);
         return;
     }
 #endif
 
     const GLenum status = glCheckFramebufferStatus(GL_FRAMEBUFFER);
 
     glBindFramebuffer(GL_FRAMEBUFFER, prevFbo);
 
     if (status != GL_FRAMEBUFFER_COMPLETE) {
         // We have an incomplete framebuffer, consider it invalid
         if (status == 0) {
             qCCritical(LIBKWINGLUTILS) << "glCheckFramebufferStatus failed: " << formatGLError(glGetError());
         } else {
             qCCritical(LIBKWINGLUTILS) << "Invalid framebuffer status: " << formatFramebufferStatus(status);
         }
         glDeleteFramebuffers(1, &mFramebuffer);
         return;
     }
 
     mValid = true;
 }
 
 void GLFramebuffer::blitFromFramebuffer(const QRect &source, const QRect &destination, GLenum filter)
 {
     if (!valid()) {
         return;
     }
 
     const GLFramebuffer *top = currentFramebuffer();
     GLFramebuffer::pushFramebuffer(this);
 
     glBindFramebuffer(GL_DRAW_FRAMEBUFFER, handle());
     glBindFramebuffer(GL_READ_FRAMEBUFFER, top->handle());
 
     const QRect s = source.isNull() ? QRect(QPoint(0, 0), top->size()) : source;
     const QRect d = destination.isNull() ? QRect(QPoint(0, 0), size()) : destination;
 
     const GLuint srcX0 = s.x();
     const GLuint srcY0 = top->size().height() - (s.y() + s.height());
     const GLuint srcX1 = s.x() + s.width();
     const GLuint srcY1 = top->size().height() - s.y();
 
     const GLuint dstX0 = d.x();
     const GLuint dstY0 = mSize.height() - (d.y() + d.height());
     const GLuint dstX1 = d.x() + d.width();
     const GLuint dstY1 = mSize.height() - d.y();
 
     glBlitFramebuffer(srcX0, srcY0, srcX1, srcY1, dstX0, dstY0, dstX1, dstY1, GL_COLOR_BUFFER_BIT, filter);
 
     GLFramebuffer::popFramebuffer();
 }
 
 // ------------------------------------------------------------------
 
 static const uint16_t indices[] = {
     1, 0, 3, 3, 2, 1, 5, 4, 7, 7, 6, 5, 9, 8, 11, 11, 10, 9,
     13, 12, 15, 15, 14, 13, 17, 16, 19, 19, 18, 17, 21, 20, 23, 23, 22, 21,
     25, 24, 27, 27, 26, 25, 29, 28, 31, 31, 30, 29, 33, 32, 35, 35, 34, 33,
     37, 36, 39, 39, 38, 37, 41, 40, 43, 43, 42, 41, 45, 44, 47, 47, 46, 45,
     49, 48, 51, 51, 50, 49, 53, 52, 55, 55, 54, 53, 57, 56, 59, 59, 58, 57,
     61, 60, 63, 63, 62, 61, 65, 64, 67, 67, 66, 65, 69, 68, 71, 71, 70, 69,
     73, 72, 75, 75, 74, 73, 77, 76, 79, 79, 78, 77, 81, 80, 83, 83, 82, 81,
     85, 84, 87, 87, 86, 85, 89, 88, 91, 91, 90, 89, 93, 92, 95, 95, 94, 93,
     97, 96, 99, 99, 98, 97, 101, 100, 103, 103, 102, 101, 105, 104, 107, 107, 106, 105,
     109, 108, 111, 111, 110, 109, 113, 112, 115, 115, 114, 113, 117, 116, 119, 119, 118, 117,
     121, 120, 123, 123, 122, 121, 125, 124, 127, 127, 126, 125, 129, 128, 131, 131, 130, 129,
     133, 132, 135, 135, 134, 133, 137, 136, 139, 139, 138, 137, 141, 140, 143, 143, 142, 141,
     145, 144, 147, 147, 146, 145, 149, 148, 151, 151, 150, 149, 153, 152, 155, 155, 154, 153,
     157, 156, 159, 159, 158, 157, 161, 160, 163, 163, 162, 161, 165, 164, 167, 167, 166, 165,
     169, 168, 171, 171, 170, 169, 173, 172, 175, 175, 174, 173, 177, 176, 179, 179, 178, 177,
     181, 180, 183, 183, 182, 181, 185, 184, 187, 187, 186, 185, 189, 188, 191, 191, 190, 189,
     193, 192, 195, 195, 194, 193, 197, 196, 199, 199, 198, 197, 201, 200, 203, 203, 202, 201,
     205, 204, 207, 207, 206, 205, 209, 208, 211, 211, 210, 209, 213, 212, 215, 215, 214, 213,
     217, 216, 219, 219, 218, 217, 221, 220, 223, 223, 222, 221, 225, 224, 227, 227, 226, 225,
     229, 228, 231, 231, 230, 229, 233, 232, 235, 235, 234, 233, 237, 236, 239, 239, 238, 237,
     241, 240, 243, 243, 242, 241, 245, 244, 247, 247, 246, 245, 249, 248, 251, 251, 250, 249,
     253, 252, 255, 255, 254, 253, 257, 256, 259, 259, 258, 257, 261, 260, 263, 263, 262, 261,
     265, 264, 267, 267, 266, 265, 269, 268, 271, 271, 270, 269, 273, 272, 275, 275, 274, 273,
     277, 276, 279, 279, 278, 277, 281, 280, 283, 283, 282, 281, 285, 284, 287, 287, 286, 285,
     289, 288, 291, 291, 290, 289, 293, 292, 295, 295, 294, 293, 297, 296, 299, 299, 298, 297,
     301, 300, 303, 303, 302, 301, 305, 304, 307, 307, 306, 305, 309, 308, 311, 311, 310, 309,
     313, 312, 315, 315, 314, 313, 317, 316, 319, 319, 318, 317, 321, 320, 323, 323, 322, 321,
     325, 324, 327, 327, 326, 325, 329, 328, 331, 331, 330, 329, 333, 332, 335, 335, 334, 333,
     337, 336, 339, 339, 338, 337, 341, 340, 343, 343, 342, 341, 345, 344, 347, 347, 346, 345,
     349, 348, 351, 351, 350, 349, 353, 352, 355, 355, 354, 353, 357, 356, 359, 359, 358, 357,
     361, 360, 363, 363, 362, 361, 365, 364, 367, 367, 366, 365, 369, 368, 371, 371, 370, 369,
     373, 372, 375, 375, 374, 373, 377, 376, 379, 379, 378, 377, 381, 380, 383, 383, 382, 381,
     385, 384, 387, 387, 386, 385, 389, 388, 391, 391, 390, 389, 393, 392, 395, 395, 394, 393,
     397, 396, 399, 399, 398, 397, 401, 400, 403, 403, 402, 401, 405, 404, 407, 407, 406, 405,
     409, 408, 411, 411, 410, 409, 413, 412, 415, 415, 414, 413, 417, 416, 419, 419, 418, 417,
     421, 420, 423, 423, 422, 421, 425, 424, 427, 427, 426, 425, 429, 428, 431, 431, 430, 429,
     433, 432, 435, 435, 434, 433, 437, 436, 439, 439, 438, 437, 441, 440, 443, 443, 442, 441,
     445, 444, 447, 447, 446, 445, 449, 448, 451, 451, 450, 449, 453, 452, 455, 455, 454, 453,
     457, 456, 459, 459, 458, 457, 461, 460, 463, 463, 462, 461, 465, 464, 467, 467, 466, 465,
     469, 468, 471, 471, 470, 469, 473, 472, 475, 475, 474, 473, 477, 476, 479, 479, 478, 477,
     481, 480, 483, 483, 482, 481, 485, 484, 487, 487, 486, 485, 489, 488, 491, 491, 490, 489,
     493, 492, 495, 495, 494, 493, 497, 496, 499, 499, 498, 497, 501, 500, 503, 503, 502, 501,
     505, 504, 507, 507, 506, 505, 509, 508, 511, 511, 510, 509, 513, 512, 515, 515, 514, 513,
     517, 516, 519, 519, 518, 517, 521, 520, 523, 523, 522, 521, 525, 524, 527, 527, 526, 525,
     529, 528, 531, 531, 530, 529, 533, 532, 535, 535, 534, 533, 537, 536, 539, 539, 538, 537,
     541, 540, 543, 543, 542, 541, 545, 544, 547, 547, 546, 545, 549, 548, 551, 551, 550, 549,
     553, 552, 555, 555, 554, 553, 557, 556, 559, 559, 558, 557, 561, 560, 563, 563, 562, 561,
     565, 564, 567, 567, 566, 565, 569, 568, 571, 571, 570, 569, 573, 572, 575, 575, 574, 573,
     577, 576, 579, 579, 578, 577, 581, 580, 583, 583, 582, 581, 585, 584, 587, 587, 586, 585,
     589, 588, 591, 591, 590, 589, 593, 592, 595, 595, 594, 593, 597, 596, 599, 599, 598, 597,
     601, 600, 603, 603, 602, 601, 605, 604, 607, 607, 606, 605, 609, 608, 611, 611, 610, 609,
     613, 612, 615, 615, 614, 613, 617, 616, 619, 619, 618, 617, 621, 620, 623, 623, 622, 621,
     625, 624, 627, 627, 626, 625, 629, 628, 631, 631, 630, 629, 633, 632, 635, 635, 634, 633,
     637, 636, 639, 639, 638, 637, 641, 640, 643, 643, 642, 641, 645, 644, 647, 647, 646, 645,
     649, 648, 651, 651, 650, 649, 653, 652, 655, 655, 654, 653, 657, 656, 659, 659, 658, 657,
     661, 660, 663, 663, 662, 661, 665, 664, 667, 667, 666, 665, 669, 668, 671, 671, 670, 669,
     673, 672, 675, 675, 674, 673, 677, 676, 679, 679, 678, 677, 681, 680, 683, 683, 682, 681,
     685, 684, 687, 687, 686, 685, 689, 688, 691, 691, 690, 689, 693, 692, 695, 695, 694, 693,
     697, 696, 699, 699, 698, 697, 701, 700, 703, 703, 702, 701, 705, 704, 707, 707, 706, 705,
     709, 708, 711, 711, 710, 709, 713, 712, 715, 715, 714, 713, 717, 716, 719, 719, 718, 717,
     721, 720, 723, 723, 722, 721, 725, 724, 727, 727, 726, 725, 729, 728, 731, 731, 730, 729,
     733, 732, 735, 735, 734, 733, 737, 736, 739, 739, 738, 737, 741, 740, 743, 743, 742, 741,
     745, 744, 747, 747, 746, 745, 749, 748, 751, 751, 750, 749, 753, 752, 755, 755, 754, 753,
     757, 756, 759, 759, 758, 757, 761, 760, 763, 763, 762, 761, 765, 764, 767, 767, 766, 765,
     769, 768, 771, 771, 770, 769, 773, 772, 775, 775, 774, 773, 777, 776, 779, 779, 778, 777,
     781, 780, 783, 783, 782, 781, 785, 784, 787, 787, 786, 785, 789, 788, 791, 791, 790, 789,
     793, 792, 795, 795, 794, 793, 797, 796, 799, 799, 798, 797, 801, 800, 803, 803, 802, 801,
     805, 804, 807, 807, 806, 805, 809, 808, 811, 811, 810, 809, 813, 812, 815, 815, 814, 813,
     817, 816, 819, 819, 818, 817, 821, 820, 823, 823, 822, 821, 825, 824, 827, 827, 826, 825,
     829, 828, 831, 831, 830, 829, 833, 832, 835, 835, 834, 833, 837, 836, 839, 839, 838, 837,
     841, 840, 843, 843, 842, 841, 845, 844, 847, 847, 846, 845, 849, 848, 851, 851, 850, 849,
     853, 852, 855, 855, 854, 853, 857, 856, 859, 859, 858, 857, 861, 860, 863, 863, 862, 861,
     865, 864, 867, 867, 866, 865, 869, 868, 871, 871, 870, 869, 873, 872, 875, 875, 874, 873,
     877, 876, 879, 879, 878, 877, 881, 880, 883, 883, 882, 881, 885, 884, 887, 887, 886, 885,
     889, 888, 891, 891, 890, 889, 893, 892, 895, 895, 894, 893, 897, 896, 899, 899, 898, 897,
     901, 900, 903, 903, 902, 901, 905, 904, 907, 907, 906, 905, 909, 908, 911, 911, 910, 909,
     913, 912, 915, 915, 914, 913, 917, 916, 919, 919, 918, 917, 921, 920, 923, 923, 922, 921,
     925, 924, 927, 927, 926, 925, 929, 928, 931, 931, 930, 929, 933, 932, 935, 935, 934, 933,
     937, 936, 939, 939, 938, 937, 941, 940, 943, 943, 942, 941, 945, 944, 947, 947, 946, 945,
     949, 948, 951, 951, 950, 949, 953, 952, 955, 955, 954, 953, 957, 956, 959, 959, 958, 957,
     961, 960, 963, 963, 962, 961, 965, 964, 967, 967, 966, 965, 969, 968, 971, 971, 970, 969,
     973, 972, 975, 975, 974, 973, 977, 976, 979, 979, 978, 977, 981, 980, 983, 983, 982, 981,
     985, 984, 987, 987, 986, 985, 989, 988, 991, 991, 990, 989, 993, 992, 995, 995, 994, 993,
     997, 996, 999, 999, 998, 997, 1001, 1000, 1003, 1003, 1002, 1001, 1005, 1004, 1007, 1007, 1006, 1005,
     1009, 1008, 1011, 1011, 1010, 1009, 1013, 1012, 1015, 1015, 1014, 1013, 1017, 1016, 1019, 1019, 1018, 1017,
     1021, 1020, 1023, 1023, 1022, 1021, 1025, 1024, 1027, 1027, 1026, 1025, 1029, 1028, 1031, 1031, 1030, 1029,
     1033, 1032, 1035, 1035, 1034, 1033, 1037, 1036, 1039, 1039, 1038, 1037, 1041, 1040, 1043, 1043, 1042, 1041,
     1045, 1044, 1047, 1047, 1046, 1045, 1049, 1048, 1051, 1051, 1050, 1049, 1053, 1052, 1055, 1055, 1054, 1053,
     1057, 1056, 1059, 1059, 1058, 1057, 1061, 1060, 1063, 1063, 1062, 1061, 1065, 1064, 1067, 1067, 1066, 1065,
     1069, 1068, 1071, 1071, 1070, 1069, 1073, 1072, 1075, 1075, 1074, 1073, 1077, 1076, 1079, 1079, 1078, 1077,
     1081, 1080, 1083, 1083, 1082, 1081, 1085, 1084, 1087, 1087, 1086, 1085, 1089, 1088, 1091, 1091, 1090, 1089,
     1093, 1092, 1095, 1095, 1094, 1093, 1097, 1096, 1099, 1099, 1098, 1097, 1101, 1100, 1103, 1103, 1102, 1101,
     1105, 1104, 1107, 1107, 1106, 1105, 1109, 1108, 1111, 1111, 1110, 1109, 1113, 1112, 1115, 1115, 1114, 1113,
     1117, 1116, 1119, 1119, 1118, 1117, 1121, 1120, 1123, 1123, 1122, 1121, 1125, 1124, 1127, 1127, 1126, 1125,
     1129, 1128, 1131, 1131, 1130, 1129, 1133, 1132, 1135, 1135, 1134, 1133, 1137, 1136, 1139, 1139, 1138, 1137,
     1141, 1140, 1143, 1143, 1142, 1141, 1145, 1144, 1147, 1147, 1146, 1145, 1149, 1148, 1151, 1151, 1150, 1149,
     1153, 1152, 1155, 1155, 1154, 1153, 1157, 1156, 1159, 1159, 1158, 1157, 1161, 1160, 1163, 1163, 1162, 1161,
     1165, 1164, 1167, 1167, 1166, 1165, 1169, 1168, 1171, 1171, 1170, 1169, 1173, 1172, 1175, 1175, 1174, 1173,
     1177, 1176, 1179, 1179, 1178, 1177, 1181, 1180, 1183, 1183, 1182, 1181, 1185, 1184, 1187, 1187, 1186, 1185,
     1189, 1188, 1191, 1191, 1190, 1189, 1193, 1192, 1195, 1195, 1194, 1193, 1197, 1196, 1199, 1199, 1198, 1197,
     1201, 1200, 1203, 1203, 1202, 1201, 1205, 1204, 1207, 1207, 1206, 1205, 1209, 1208, 1211, 1211, 1210, 1209,
     1213, 1212, 1215, 1215, 1214, 1213, 1217, 1216, 1219, 1219, 1218, 1217, 1221, 1220, 1223, 1223, 1222, 1221,
     1225, 1224, 1227, 1227, 1226, 1225, 1229, 1228, 1231, 1231, 1230, 1229, 1233, 1232, 1235, 1235, 1234, 1233,
     1237, 1236, 1239, 1239, 1238, 1237, 1241, 1240, 1243, 1243, 1242, 1241, 1245, 1244, 1247, 1247, 1246, 1245,
     1249, 1248, 1251, 1251, 1250, 1249, 1253, 1252, 1255, 1255, 1254, 1253, 1257, 1256, 1259, 1259, 1258, 1257,
     1261, 1260, 1263, 1263, 1262, 1261, 1265, 1264, 1267, 1267, 1266, 1265, 1269, 1268, 1271, 1271, 1270, 1269,
     1273, 1272, 1275, 1275, 1274, 1273, 1277, 1276, 1279, 1279, 1278, 1277, 1281, 1280, 1283, 1283, 1282, 1281,
     1285, 1284, 1287, 1287, 1286, 1285, 1289, 1288, 1291, 1291, 1290, 1289, 1293, 1292, 1295, 1295, 1294, 1293,
     1297, 1296, 1299, 1299, 1298, 1297, 1301, 1300, 1303, 1303, 1302, 1301, 1305, 1304, 1307, 1307, 1306, 1305,
     1309, 1308, 1311, 1311, 1310, 1309, 1313, 1312, 1315, 1315, 1314, 1313, 1317, 1316, 1319, 1319, 1318, 1317,
     1321, 1320, 1323, 1323, 1322, 1321, 1325, 1324, 1327, 1327, 1326, 1325, 1329, 1328, 1331, 1331, 1330, 1329,
     1333, 1332, 1335, 1335, 1334, 1333, 1337, 1336, 1339, 1339, 1338, 1337, 1341, 1340, 1343, 1343, 1342, 1341,
     1345, 1344, 1347, 1347, 1346, 1345, 1349, 1348, 1351, 1351, 1350, 1349, 1353, 1352, 1355, 1355, 1354, 1353,
     1357, 1356, 1359, 1359, 1358, 1357, 1361, 1360, 1363, 1363, 1362, 1361, 1365, 1364, 1367, 1367, 1366, 1365,
     1369, 1368, 1371, 1371, 1370, 1369, 1373, 1372, 1375, 1375, 1374, 1373, 1377, 1376, 1379, 1379, 1378, 1377,
     1381, 1380, 1383, 1383, 1382, 1381, 1385, 1384, 1387, 1387, 1386, 1385, 1389, 1388, 1391, 1391, 1390, 1389,
     1393, 1392, 1395, 1395, 1394, 1393, 1397, 1396, 1399, 1399, 1398, 1397, 1401, 1400, 1403, 1403, 1402, 1401,
     1405, 1404, 1407, 1407, 1406, 1405, 1409, 1408, 1411, 1411, 1410, 1409, 1413, 1412, 1415, 1415, 1414, 1413,
     1417, 1416, 1419, 1419, 1418, 1417, 1421, 1420, 1423, 1423, 1422, 1421, 1425, 1424, 1427, 1427, 1426, 1425,
     1429, 1428, 1431, 1431, 1430, 1429, 1433, 1432, 1435, 1435, 1434, 1433, 1437, 1436, 1439, 1439, 1438, 1437,
     1441, 1440, 1443, 1443, 1442, 1441, 1445, 1444, 1447, 1447, 1446, 1445, 1449, 1448, 1451, 1451, 1450, 1449,
     1453, 1452, 1455, 1455, 1454, 1453, 1457, 1456, 1459, 1459, 1458, 1457, 1461, 1460, 1463, 1463, 1462, 1461,
     1465, 1464, 1467, 1467, 1466, 1465, 1469, 1468, 1471, 1471, 1470, 1469, 1473, 1472, 1475, 1475, 1474, 1473,
     1477, 1476, 1479, 1479, 1478, 1477, 1481, 1480, 1483, 1483, 1482, 1481, 1485, 1484, 1487, 1487, 1486, 1485,
     1489, 1488, 1491, 1491, 1490, 1489, 1493, 1492, 1495, 1495, 1494, 1493, 1497, 1496, 1499, 1499, 1498, 1497,
     1501, 1500, 1503, 1503, 1502, 1501, 1505, 1504, 1507, 1507, 1506, 1505, 1509, 1508, 1511, 1511, 1510, 1509,
     1513, 1512, 1515, 1515, 1514, 1513, 1517, 1516, 1519, 1519, 1518, 1517, 1521, 1520, 1523, 1523, 1522, 1521,
     1525, 1524, 1527, 1527, 1526, 1525, 1529, 1528, 1531, 1531, 1530, 1529, 1533, 1532, 1535, 1535, 1534, 1533,
     1537, 1536, 1539, 1539, 1538, 1537, 1541, 1540, 1543, 1543, 1542, 1541, 1545, 1544, 1547, 1547, 1546, 1545,
     1549, 1548, 1551, 1551, 1550, 1549, 1553, 1552, 1555, 1555, 1554, 1553, 1557, 1556, 1559, 1559, 1558, 1557,
     1561, 1560, 1563, 1563, 1562, 1561, 1565, 1564, 1567, 1567, 1566, 1565, 1569, 1568, 1571, 1571, 1570, 1569,
     1573, 1572, 1575, 1575, 1574, 1573, 1577, 1576, 1579, 1579, 1578, 1577, 1581, 1580, 1583, 1583, 1582, 1581,
     1585, 1584, 1587, 1587, 1586, 1585, 1589, 1588, 1591, 1591, 1590, 1589, 1593, 1592, 1595, 1595, 1594, 1593,
     1597, 1596, 1599, 1599, 1598, 1597, 1601, 1600, 1603, 1603, 1602, 1601, 1605, 1604, 1607, 1607, 1606, 1605,
     1609, 1608, 1611, 1611, 1610, 1609, 1613, 1612, 1615, 1615, 1614, 1613, 1617, 1616, 1619, 1619, 1618, 1617,
     1621, 1620, 1623, 1623, 1622, 1621, 1625, 1624, 1627, 1627, 1626, 1625, 1629, 1628, 1631, 1631, 1630, 1629,
     1633, 1632, 1635, 1635, 1634, 1633, 1637, 1636, 1639, 1639, 1638, 1637, 1641, 1640, 1643, 1643, 1642, 1641,
     1645, 1644, 1647, 1647, 1646, 1645, 1649, 1648, 1651, 1651, 1650, 1649, 1653, 1652, 1655, 1655, 1654, 1653,
     1657, 1656, 1659, 1659, 1658, 1657, 1661, 1660, 1663, 1663, 1662, 1661, 1665, 1664, 1667, 1667, 1666, 1665,
     1669, 1668, 1671, 1671, 1670, 1669, 1673, 1672, 1675, 1675, 1674, 1673, 1677, 1676, 1679, 1679, 1678, 1677,
     1681, 1680, 1683, 1683, 1682, 1681, 1685, 1684, 1687, 1687, 1686, 1685, 1689, 1688, 1691, 1691, 1690, 1689,
     1693, 1692, 1695, 1695, 1694, 1693, 1697, 1696, 1699, 1699, 1698, 1697, 1701, 1700, 1703, 1703, 1702, 1701,
     1705, 1704, 1707, 1707, 1706, 1705, 1709, 1708, 1711, 1711, 1710, 1709, 1713, 1712, 1715, 1715, 1714, 1713,
     1717, 1716, 1719, 1719, 1718, 1717, 1721, 1720, 1723, 1723, 1722, 1721, 1725, 1724, 1727, 1727, 1726, 1725,
     1729, 1728, 1731, 1731, 1730, 1729, 1733, 1732, 1735, 1735, 1734, 1733, 1737, 1736, 1739, 1739, 1738, 1737,
     1741, 1740, 1743, 1743, 1742, 1741, 1745, 1744, 1747, 1747, 1746, 1745, 1749, 1748, 1751, 1751, 1750, 1749,
     1753, 1752, 1755, 1755, 1754, 1753, 1757, 1756, 1759, 1759, 1758, 1757, 1761, 1760, 1763, 1763, 1762, 1761,
     1765, 1764, 1767, 1767, 1766, 1765, 1769, 1768, 1771, 1771, 1770, 1769, 1773, 1772, 1775, 1775, 1774, 1773,
     1777, 1776, 1779, 1779, 1778, 1777, 1781, 1780, 1783, 1783, 1782, 1781, 1785, 1784, 1787, 1787, 1786, 1785,
     1789, 1788, 1791, 1791, 1790, 1789, 1793, 1792, 1795, 1795, 1794, 1793, 1797, 1796, 1799, 1799, 1798, 1797,
     1801, 1800, 1803, 1803, 1802, 1801, 1805, 1804, 1807, 1807, 1806, 1805, 1809, 1808, 1811, 1811, 1810, 1809,
     1813, 1812, 1815, 1815, 1814, 1813, 1817, 1816, 1819, 1819, 1818, 1817, 1821, 1820, 1823, 1823, 1822, 1821,
     1825, 1824, 1827, 1827, 1826, 1825, 1829, 1828, 1831, 1831, 1830, 1829, 1833, 1832, 1835, 1835, 1834, 1833,
     1837, 1836, 1839, 1839, 1838, 1837, 1841, 1840, 1843, 1843, 1842, 1841, 1845, 1844, 1847, 1847, 1846, 1845,
     1849, 1848, 1851, 1851, 1850, 1849, 1853, 1852, 1855, 1855, 1854, 1853, 1857, 1856, 1859, 1859, 1858, 1857,
     1861, 1860, 1863, 1863, 1862, 1861, 1865, 1864, 1867, 1867, 1866, 1865, 1869, 1868, 1871, 1871, 1870, 1869,
     1873, 1872, 1875, 1875, 1874, 1873, 1877, 1876, 1879, 1879, 1878, 1877, 1881, 1880, 1883, 1883, 1882, 1881,
     1885, 1884, 1887, 1887, 1886, 1885, 1889, 1888, 1891, 1891, 1890, 1889, 1893, 1892, 1895, 1895, 1894, 1893,
     1897, 1896, 1899, 1899, 1898, 1897, 1901, 1900, 1903, 1903, 1902, 1901, 1905, 1904, 1907, 1907, 1906, 1905,
     1909, 1908, 1911, 1911, 1910, 1909, 1913, 1912, 1915, 1915, 1914, 1913, 1917, 1916, 1919, 1919, 1918, 1917,
     1921, 1920, 1923, 1923, 1922, 1921, 1925, 1924, 1927, 1927, 1926, 1925, 1929, 1928, 1931, 1931, 1930, 1929,
     1933, 1932, 1935, 1935, 1934, 1933, 1937, 1936, 1939, 1939, 1938, 1937, 1941, 1940, 1943, 1943, 1942, 1941,
     1945, 1944, 1947, 1947, 1946, 1945, 1949, 1948, 1951, 1951, 1950, 1949, 1953, 1952, 1955, 1955, 1954, 1953,
     1957, 1956, 1959, 1959, 1958, 1957, 1961, 1960, 1963, 1963, 1962, 1961, 1965, 1964, 1967, 1967, 1966, 1965,
     1969, 1968, 1971, 1971, 1970, 1969, 1973, 1972, 1975, 1975, 1974, 1973, 1977, 1976, 1979, 1979, 1978, 1977,
     1981, 1980, 1983, 1983, 1982, 1981, 1985, 1984, 1987, 1987, 1986, 1985, 1989, 1988, 1991, 1991, 1990, 1989,
     1993, 1992, 1995, 1995, 1994, 1993, 1997, 1996, 1999, 1999, 1998, 1997, 2001, 2000, 2003, 2003, 2002, 2001,
     2005, 2004, 2007, 2007, 2006, 2005, 2009, 2008, 2011, 2011, 2010, 2009, 2013, 2012, 2015, 2015, 2014, 2013,
     2017, 2016, 2019, 2019, 2018, 2017, 2021, 2020, 2023, 2023, 2022, 2021, 2025, 2024, 2027, 2027, 2026, 2025,
     2029, 2028, 2031, 2031, 2030, 2029, 2033, 2032, 2035, 2035, 2034, 2033, 2037, 2036, 2039, 2039, 2038, 2037,
     2041, 2040, 2043, 2043, 2042, 2041, 2045, 2044, 2047, 2047, 2046, 2045};
 
 // Certain GPUs, especially mobile, require the data copied to the GPU to be aligned to a
 // certain amount of bytes. For example, the Mali GPU requires data to be aligned to 8 bytes.
 // This function helps ensure that the data is aligned.
 template<typename T>
 T align(T value, int bytes)
 {
     return (value + bytes - 1) & ~T(bytes - 1);
 }
 
 class IndexBuffer
 {
 public:
     IndexBuffer();
     ~IndexBuffer();
 
     void accommodate(int count);
     void bind();
 
 private:
     GLuint m_buffer;
     size_t m_size;
     int m_count;
 };
 
 IndexBuffer::IndexBuffer()
 {
     // The maximum number of quads we can render with 16 bit indices is 16,384.
     // But we start with 512 and grow the buffer as needed.
     m_size = sizeof(indices);
     m_count = m_size / (6 * sizeof(uint16_t));
 
     glGenBuffers(1, &m_buffer);
     glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, m_buffer);
     glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indices), indices, GL_STATIC_DRAW);
 }
 
 IndexBuffer::~IndexBuffer()
 {
     glDeleteBuffers(1, &m_buffer);
 }
 
 void IndexBuffer::accommodate(int count)
 {
     // Check if we need to grow the buffer.
     if (count <= m_count) {
         return;
     }
 
     size_t size = 6 * sizeof(uint16_t) * count;
 
     // Create a new buffer object
     GLuint buffer;
     glGenBuffers(1, &buffer);
     glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, buffer);
     glBufferData(GL_ELEMENT_ARRAY_BUFFER, size, nullptr, GL_STATIC_DRAW);
 
     // Use the GPU to copy the data from the old object to the new object,
     glBindBuffer(GL_COPY_READ_BUFFER, m_buffer);
     glCopyBufferSubData(GL_COPY_READ_BUFFER, GL_ELEMENT_ARRAY_BUFFER, 0, 0, m_size);
     glDeleteBuffers(1, &m_buffer);
     glFlush(); // Needed to work around what appears to be a CP DMA issue in r600g
 
     // Map the new object and fill in the uninitialized section
     const GLbitfield access = GL_MAP_WRITE_BIT | GL_MAP_UNSYNCHRONIZED_BIT | GL_MAP_INVALIDATE_RANGE_BIT;
     uint16_t *map = (uint16_t *)glMapBufferRange(GL_ELEMENT_ARRAY_BUFFER, m_size, size - m_size, access);
 
     const uint16_t index[] = {1, 0, 3, 3, 2, 1};
     for (int i = m_count; i < count; i++) {
         for (int j = 0; j < 6; j++) {
             *(map++) = i * 4 + index[j];
         }
     }
 
     glUnmapBuffer(GL_ELEMENT_ARRAY_BUFFER);
     m_buffer = buffer;
     m_count = count;
     m_size = size;
 }
 
 void IndexBuffer::bind()
 {
     glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, m_buffer);
 }
 
 // ------------------------------------------------------------------
 
 class BitRef
 {
 public:
     BitRef(uint32_t &bitfield, int bit)
         : m_bitfield(bitfield)
         , m_mask(1 << bit)
     {
     }
 
     void operator=(bool val)
     {
         if (val) {
             m_bitfield |= m_mask;
         } else {
             m_bitfield &= ~m_mask;
         }
     }
 
     operator bool() const
     {
         return m_bitfield & m_mask;
     }
 
 private:
     uint32_t &m_bitfield;
     int const m_mask;
 };
 
 // ------------------------------------------------------------------
 
 class Bitfield
 {
 public:
     Bitfield()
         : m_bitfield(0)
     {
     }
     Bitfield(uint32_t bits)
         : m_bitfield(bits)
     {
     }
 
     void set(int i)
     {
         m_bitfield |= (1 << i);
     }
     void clear(int i)
     {
         m_bitfield &= ~(1 << i);
     }
 
     BitRef operator[](int i)
     {
         return BitRef(m_bitfield, i);
     }
     operator uint32_t() const
     {
         return m_bitfield;
     }
 
 private:
     uint32_t m_bitfield;
 };
 
 // ------------------------------------------------------------------
 
 class BitfieldIterator
 {
 public:
     BitfieldIterator(uint32_t bitfield)
         : m_bitfield(bitfield)
     {
     }
 
     bool hasNext() const
     {
         return m_bitfield != 0;
     }
 
     int next()
     {
         const int bit = ffs(m_bitfield) - 1;
         m_bitfield ^= (1 << bit);
         return bit;
     }
 
 private:
     uint32_t m_bitfield;
 };
 
 // ------------------------------------------------------------------
 
 struct VertexAttrib
 {
     int size;
     GLenum type;
     int offset;
 };
 
 // ------------------------------------------------------------------
 
 struct BufferFence
 {
     GLsync sync;
     intptr_t nextEnd;
 
     bool signaled() const
     {
         GLint value;
         glGetSynciv(sync, GL_SYNC_STATUS, 1, nullptr, &value);
         return value == GL_SIGNALED;
     }
 };
 
 static void deleteAll(std::deque<BufferFence> &fences)
 {
     for (const BufferFence &fence : fences) {
         glDeleteSync(fence.sync);
     }
 
     fences.clear();
 }
 
 // ------------------------------------------------------------------
 
 template<size_t Count>
 struct FrameSizesArray
 {
 public:
     FrameSizesArray()
     {
         m_array.fill(0);
     }
 
     void push(size_t size)
     {
         m_array[m_index] = size;
         m_index = (m_index + 1) % Count;
     }
 
     size_t average() const
     {
         size_t sum = 0;
         for (size_t size : m_array) {
             sum += size;
         }
         return sum / Count;
     }
 
 private:
     std::array<size_t, Count> m_array;
     int m_index = 0;
 };
 
 //*********************************
 // GLVertexBufferPrivate
 //*********************************
 class GLVertexBufferPrivate
 {
 public:
     GLVertexBufferPrivate(GLVertexBuffer::UsageHint usageHint)
         : vertexCount(0)
         , persistent(false)
         , useColor(false)
         , color(0, 0, 0, 255)
         , bufferSize(0)
         , bufferEnd(0)
         , mappedSize(0)
         , frameSize(0)
         , nextOffset(0)
         , baseAddress(0)
         , map(nullptr)
     {
         glGenBuffers(1, &buffer);
 
         switch (usageHint) {
         case GLVertexBuffer::Dynamic:
             usage = GL_DYNAMIC_DRAW;
             break;
         case GLVertexBuffer::Static:
             usage = GL_STATIC_DRAW;
             break;
         default:
             usage = GL_STREAM_DRAW;
             break;
         }
     }
 
     ~GLVertexBufferPrivate()
     {
         deleteAll(fences);
 
         if (buffer != 0) {
             glDeleteBuffers(1, &buffer);
             map = nullptr;
         }
     }
 
     void interleaveArrays(float *array, int dim, const float *vertices, const float *texcoords, int count);
     void bindArrays();
     void unbindArrays();
     void reallocateBuffer(size_t size);
     GLvoid *mapNextFreeRange(size_t size);
     void reallocatePersistentBuffer(size_t size);
     bool awaitFence(intptr_t offset);
     GLvoid *getIdleRange(size_t size);
 
     GLuint buffer;
     GLenum usage;
     int stride;
     int vertexCount;
     static std::unique_ptr<GLVertexBuffer> streamingBuffer;
     static bool haveBufferStorage;
     static bool haveSyncFences;
     static bool hasMapBufferRange;
     static bool supportsIndexedQuads;
     QByteArray dataStore;
     bool persistent;
     bool useColor;
     QVector4D color;
     size_t bufferSize;
     intptr_t bufferEnd;
     size_t mappedSize;
     size_t frameSize;
     intptr_t nextOffset;
     intptr_t baseAddress;
     uint8_t *map;
     std::deque<BufferFence> fences;
     FrameSizesArray<4> frameSizes;
     VertexAttrib attrib[VertexAttributeCount];
     Bitfield enabledArrays;
     static std::unique_ptr<IndexBuffer> s_indexBuffer;
 };
 
 bool GLVertexBufferPrivate::hasMapBufferRange = false;
 bool GLVertexBufferPrivate::supportsIndexedQuads = false;
 std::unique_ptr<GLVertexBuffer> GLVertexBufferPrivate::streamingBuffer;
 bool GLVertexBufferPrivate::haveBufferStorage = false;
 bool GLVertexBufferPrivate::haveSyncFences = false;
 std::unique_ptr<IndexBuffer> GLVertexBufferPrivate::s_indexBuffer;
 
 void GLVertexBufferPrivate::interleaveArrays(float *dst, int dim,
                                              const float *vertices, const float *texcoords,
                                              int count)
 {
     if (!texcoords) {
         memcpy((void *)dst, vertices, dim * sizeof(float) * count);
         return;
     }
 
     switch (dim) {
     case 2:
         for (int i = 0; i < count; i++) {
             *(dst++) = *(vertices++);
             *(dst++) = *(vertices++);
             *(dst++) = *(texcoords++);
             *(dst++) = *(texcoords++);
         }
         break;
 
     case 3:
         for (int i = 0; i < count; i++) {
             *(dst++) = *(vertices++);
             *(dst++) = *(vertices++);
             *(dst++) = *(vertices++);
             *(dst++) = *(texcoords++);
             *(dst++) = *(texcoords++);
         }
         break;
 
     default:
         for (int i = 0; i < count; i++) {
             for (int j = 0; j < dim; j++) {
                 *(dst++) = *(vertices++);
             }
 
             *(dst++) = *(texcoords++);
             *(dst++) = *(texcoords++);
         }
     }
 }
 
 void GLVertexBufferPrivate::bindArrays()
 {
     if (useColor) {
         GLShader *shader = ShaderManager::instance()->getBoundShader();
         shader->setUniform(GLShader::Color, color);
     }
 
     glBindBuffer(GL_ARRAY_BUFFER, buffer);
 
     BitfieldIterator it(enabledArrays);
     while (it.hasNext()) {
         const int index = it.next();
         glVertexAttribPointer(index, attrib[index].size, attrib[index].type, GL_FALSE, stride,
                               (const GLvoid *)(baseAddress + attrib[index].offset));
         glEnableVertexAttribArray(index);
     }
 }
 
 void GLVertexBufferPrivate::unbindArrays()
 {
     BitfieldIterator it(enabledArrays);
     while (it.hasNext()) {
         glDisableVertexAttribArray(it.next());
     }
 }
 
 void GLVertexBufferPrivate::reallocatePersistentBuffer(size_t size)
 {
     if (buffer != 0) {
         // This also unmaps and unbinds the buffer
         glDeleteBuffers(1, &buffer);
         buffer = 0;
 
         deleteAll(fences);
     }
 
     if (buffer == 0) {
         glGenBuffers(1, &buffer);
     }
 
     // Round the size up to 64 kb
     size_t minSize = std::max<size_t>(frameSizes.average() * 3, 128 * 1024);
     bufferSize = std::max(size, minSize);
 
     const GLbitfield storage = GL_DYNAMIC_STORAGE_BIT;
     const GLbitfield access = GL_MAP_WRITE_BIT | GL_MAP_PERSISTENT_BIT | GL_MAP_COHERENT_BIT;
 
     glBindBuffer(GL_ARRAY_BUFFER, buffer);
     glBufferStorage(GL_ARRAY_BUFFER, bufferSize, nullptr, storage | access);
 
     map = (uint8_t *)glMapBufferRange(GL_ARRAY_BUFFER, 0, bufferSize, access);
 
     nextOffset = 0;
     bufferEnd = bufferSize;
 }
 
 bool GLVertexBufferPrivate::awaitFence(intptr_t end)
 {
     // Skip fences until we reach the end offset
     while (!fences.empty() && fences.front().nextEnd < end) {
         glDeleteSync(fences.front().sync);
         fences.pop_front();
     }
 
     Q_ASSERT(!fences.empty());
 
     // Wait on the next fence
     const BufferFence &fence = fences.front();
 
     if (!fence.signaled()) {
         qCDebug(LIBKWINGLUTILS) << "Stalling on VBO fence";
         const GLenum ret = glClientWaitSync(fence.sync, GL_SYNC_FLUSH_COMMANDS_BIT, 1000000000);
 
         if (ret == GL_TIMEOUT_EXPIRED || ret == GL_WAIT_FAILED) {
             qCCritical(LIBKWINGLUTILS) << "Wait failed";
             return false;
         }
     }
 
     glDeleteSync(fence.sync);
 
     // Update the end pointer
     bufferEnd = fence.nextEnd;
     fences.pop_front();
 
     return true;
 }
 
 GLvoid *GLVertexBufferPrivate::getIdleRange(size_t size)
 {
     if (unlikely(size > bufferSize)) {
         reallocatePersistentBuffer(size * 2);
     }
 
     // Handle wrap-around
     if (unlikely(nextOffset + size > bufferSize)) {
         nextOffset = 0;
         bufferEnd -= bufferSize;
 
         for (BufferFence &fence : fences) {
             fence.nextEnd -= bufferSize;
         }
 
         // Emit a fence now
         if (auto sync = glFenceSync(GL_SYNC_GPU_COMMANDS_COMPLETE, 0)) {
             fences.push_back(BufferFence{
                 .sync = sync,
                 .nextEnd = intptr_t(bufferSize)});
         }
     }
 
     if (unlikely(nextOffset + intptr_t(size) > bufferEnd)) {
         if (!awaitFence(nextOffset + size)) {
             return nullptr;
         }
     }
 
     return map + nextOffset;
 }
 
 void GLVertexBufferPrivate::reallocateBuffer(size_t size)
 {
     // Round the size up to 4 Kb for streaming/dynamic buffers.
     const size_t minSize = 32768; // Minimum size for streaming buffers
     const size_t alloc = usage != GL_STATIC_DRAW ? std::max(size, minSize) : size;
 
     glBufferData(GL_ARRAY_BUFFER, alloc, nullptr, usage);
 
     bufferSize = alloc;
 }
 
 GLvoid *GLVertexBufferPrivate::mapNextFreeRange(size_t size)
 {
     GLbitfield access = GL_MAP_WRITE_BIT | GL_MAP_INVALIDATE_RANGE_BIT | GL_MAP_UNSYNCHRONIZED_BIT;
 
     if ((nextOffset + size) > bufferSize) {
         // Reallocate the data store if it's too small.
         if (size > bufferSize) {
             reallocateBuffer(size);
         } else {
             access |= GL_MAP_INVALIDATE_BUFFER_BIT;
             access ^= GL_MAP_UNSYNCHRONIZED_BIT;
         }
 
         nextOffset = 0;
     }
 
     return glMapBufferRange(GL_ARRAY_BUFFER, nextOffset, size, access);
 }
 
 //*********************************
 // GLVertexBuffer
 //*********************************
 
 const GLVertexAttrib GLVertexBuffer::GLVertex2DLayout[2] = {
     {VA_Position, 2, GL_FLOAT, offsetof(GLVertex2D, position)},
     {VA_TexCoord, 2, GL_FLOAT, offsetof(GLVertex2D, texcoord)},
 };
 
 const GLVertexAttrib GLVertexBuffer::GLVertex3DLayout[2] = {
     {VA_Position, 3, GL_FLOAT, offsetof(GLVertex3D, position)},
     {VA_TexCoord, 2, GL_FLOAT, offsetof(GLVertex3D, texcoord)},
 };
 
 GLVertexBuffer::GLVertexBuffer(UsageHint hint)
     : d(std::make_unique<GLVertexBufferPrivate>(hint))
 {
 }
 
 GLVertexBuffer::~GLVertexBuffer() = default;
 
 void GLVertexBuffer::setData(const void *data, size_t size)
 {
     GLvoid *ptr = map(size);
     memcpy(ptr, data, size);
     unmap();
 }
 
 void GLVertexBuffer::setData(int vertexCount, int dim, const float *vertices, const float *texcoords)
 {
     const GLVertexAttrib layout[] = {
         {VA_Position, dim, GL_FLOAT, 0},
         {VA_TexCoord, 2, GL_FLOAT, int(dim * sizeof(float))}};
 
     int stride = (texcoords ? dim + 2 : dim) * sizeof(float);
     int attribCount = texcoords ? 2 : 1;
 
     setAttribLayout(layout, attribCount, stride);
     setVertexCount(vertexCount);
 
     GLvoid *ptr = map(vertexCount * stride);
     d->interleaveArrays((float *)ptr, dim, vertices, texcoords, vertexCount);
     unmap();
 }
 
 GLvoid *GLVertexBuffer::map(size_t size)
 {
     d->mappedSize = size;
     d->frameSize += size;
 
     if (d->persistent) {
         return d->getIdleRange(size);
     }
 
     glBindBuffer(GL_ARRAY_BUFFER, d->buffer);
 
     bool preferBufferSubData = GLPlatform::instance()->preferBufferSubData();
 
     if (GLVertexBufferPrivate::hasMapBufferRange && !preferBufferSubData) {
         return (GLvoid *)d->mapNextFreeRange(size);
     }
 
     // If we can't map the buffer we allocate local memory to hold the
     // buffer data and return a pointer to it.  The data will be submitted
     // to the actual buffer object when the user calls unmap().
     if (size_t(d->dataStore.size()) < size) {
         d->dataStore.resize(size);
     }
 
     return (GLvoid *)d->dataStore.data();
 }
 
 void GLVertexBuffer::unmap()
 {
     if (d->persistent) {
         d->baseAddress = d->nextOffset;
         d->nextOffset += align(d->mappedSize, 8);
         d->mappedSize = 0;
         return;
     }
 
     bool preferBufferSubData = GLPlatform::instance()->preferBufferSubData();
 
     if (GLVertexBufferPrivate::hasMapBufferRange && !preferBufferSubData) {
         glUnmapBuffer(GL_ARRAY_BUFFER);
 
         d->baseAddress = d->nextOffset;
         d->nextOffset += align(d->mappedSize, 8);
     } else {
         // Upload the data from local memory to the buffer object
         if (preferBufferSubData) {
             if ((d->nextOffset + d->mappedSize) > d->bufferSize) {
                 d->reallocateBuffer(d->mappedSize);
                 d->nextOffset = 0;
             }
 
             glBufferSubData(GL_ARRAY_BUFFER, d->nextOffset, d->mappedSize, d->dataStore.constData());
 
             d->baseAddress = d->nextOffset;
             d->nextOffset += align(d->mappedSize, 8);
         } else {
             glBufferData(GL_ARRAY_BUFFER, d->mappedSize, d->dataStore.data(), d->usage);
             d->baseAddress = 0;
         }
 
         // Free the local memory buffer if it's unlikely to be used again
         if (d->usage == GL_STATIC_DRAW) {
             d->dataStore = QByteArray();
         }
     }
 
     d->mappedSize = 0;
 }
 
 void GLVertexBuffer::setVertexCount(int count)
 {
     d->vertexCount = count;
 }
 
 void GLVertexBuffer::setAttribLayout(const GLVertexAttrib *attribs, int count, int stride)
 {
     // Start by disabling all arrays
     d->enabledArrays = 0;
 
     for (int i = 0; i < count; i++) {
         const int index = attribs[i].index;
 
         Q_ASSERT(index >= 0 && index < VertexAttributeCount);
         Q_ASSERT(!d->enabledArrays[index]);
 
         d->attrib[index].size = attribs[i].size;
         d->attrib[index].type = attribs[i].type;
         d->attrib[index].offset = attribs[i].relativeOffset;
 
         d->enabledArrays[index] = true;
     }
 
     d->stride = stride;
 }
 
 void GLVertexBuffer::render(GLenum primitiveMode)
 {
     render(infiniteRegion(), primitiveMode, false);
 }
 
 void GLVertexBuffer::render(const QRegion &region, GLenum primitiveMode, bool hardwareClipping)
 {
     d->bindArrays();
     draw(region, primitiveMode, 0, d->vertexCount, hardwareClipping);
     d->unbindArrays();
 }
 
 void GLVertexBuffer::bindArrays()
 {
     d->bindArrays();
 }
 
 void GLVertexBuffer::unbindArrays()
 {
     d->unbindArrays();
 }
 
 void GLVertexBuffer::draw(GLenum primitiveMode, int first, int count)
 {
     draw(infiniteRegion(), primitiveMode, first, count, false);
 }
 
 void GLVertexBuffer::draw(const QRegion &region, GLenum primitiveMode, int first, int count, bool hardwareClipping)
 {
     if (primitiveMode == GL_QUADS) {
         if (!GLVertexBufferPrivate::s_indexBuffer) {
             GLVertexBufferPrivate::s_indexBuffer = std::make_unique<IndexBuffer>();
         }
 
         GLVertexBufferPrivate::s_indexBuffer->bind();
         GLVertexBufferPrivate::s_indexBuffer->accommodate(count / 4);
 
         count = count * 6 / 4;
 
         if (!hardwareClipping) {
             glDrawElementsBaseVertex(GL_TRIANGLES, count, GL_UNSIGNED_SHORT, nullptr, first);
         } else {
             // Clip using scissoring
             const GLFramebuffer *current = GLFramebuffer::currentFramebuffer();
             for (const QRect &r : region) {
                 glScissor(r.x(), current->size().height() - (r.y() + r.height()), r.width(), r.height());
                 glDrawElementsBaseVertex(GL_TRIANGLES, count, GL_UNSIGNED_SHORT, nullptr, first);
             }
         }
         return;
     }
 
     if (!hardwareClipping) {
         glDrawArrays(primitiveMode, first, count);
     } else {
         // Clip using scissoring
         const GLFramebuffer *current = GLFramebuffer::currentFramebuffer();
         for (const QRect &r : region) {
             glScissor(r.x(), current->size().height() - (r.y() + r.height()), r.width(), r.height());
             glDrawArrays(primitiveMode, first, count);
         }
     }
 }
 
 bool GLVertexBuffer::supportsIndexedQuads()
 {
     return GLVertexBufferPrivate::supportsIndexedQuads;
 }
 
 bool GLVertexBuffer::isUseColor() const
 {
     return d->useColor;
 }
 
 void GLVertexBuffer::setUseColor(bool enable)
 {
     d->useColor = enable;
 }
 
 void GLVertexBuffer::setColor(const QColor &color, bool enable)
 {
     d->useColor = enable;
     d->color = QVector4D(color.redF(), color.greenF(), color.blueF(), color.alphaF());
 }
 
 void GLVertexBuffer::reset()
 {
     d->useColor = false;
     d->color = QVector4D(0, 0, 0, 1);
     d->vertexCount = 0;
 }
 
 void GLVertexBuffer::endOfFrame()
 {
     if (!d->persistent) {
         return;
     }
 
     // Emit a fence if we have uploaded data
     if (d->frameSize > 0) {
         d->frameSizes.push(d->frameSize);
         d->frameSize = 0;
 
         // Force the buffer to be reallocated at the beginning of the next frame
         // if the average frame size is greater than half the size of the buffer
         if (unlikely(d->frameSizes.average() > d->bufferSize / 2)) {
             deleteAll(d->fences);
             glDeleteBuffers(1, &d->buffer);
 
             d->buffer = 0;
             d->bufferSize = 0;
             d->nextOffset = 0;
             d->map = nullptr;
         } else {
             if (auto sync = glFenceSync(GL_SYNC_GPU_COMMANDS_COMPLETE, 0)) {
                 d->fences.push_back(BufferFence{
                     .sync = sync,
                     .nextEnd = intptr_t(d->nextOffset + d->bufferSize)});
             }
         }
     }
 }
 
 void GLVertexBuffer::beginFrame()
 {
     if (!d->persistent) {
         return;
     }
 
     // Remove finished fences from the list and update the bufferEnd offset
     while (d->fences.size() > 1 && d->fences.front().signaled()) {
         const BufferFence &fence = d->fences.front();
         glDeleteSync(fence.sync);
 
         d->bufferEnd = fence.nextEnd;
         d->fences.pop_front();
     }
 }
 
 void GLVertexBuffer::initStatic()
 {
     if (GLPlatform::instance()->isGLES()) {
         bool haveBaseVertex = hasGLExtension(QByteArrayLiteral("GL_OES_draw_elements_base_vertex"));
         bool haveCopyBuffer = hasGLVersion(3, 0);
         bool haveMapBufferRange = hasGLExtension(QByteArrayLiteral("GL_EXT_map_buffer_range"));
 
         GLVertexBufferPrivate::hasMapBufferRange = haveMapBufferRange;
         GLVertexBufferPrivate::supportsIndexedQuads = haveBaseVertex && haveCopyBuffer && haveMapBufferRange;
         GLVertexBufferPrivate::haveBufferStorage = hasGLExtension("GL_EXT_buffer_storage");
         GLVertexBufferPrivate::haveSyncFences = hasGLVersion(3, 0);
     } else {
         bool haveBaseVertex = hasGLVersion(3, 2) || hasGLExtension(QByteArrayLiteral("GL_ARB_draw_elements_base_vertex"));
         bool haveCopyBuffer = hasGLVersion(3, 1) || hasGLExtension(QByteArrayLiteral("GL_ARB_copy_buffer"));
         bool haveMapBufferRange = hasGLVersion(3, 0) || hasGLExtension(QByteArrayLiteral("GL_ARB_map_buffer_range"));
 
         GLVertexBufferPrivate::hasMapBufferRange = haveMapBufferRange;
         GLVertexBufferPrivate::supportsIndexedQuads = haveBaseVertex && haveCopyBuffer && haveMapBufferRange;
         GLVertexBufferPrivate::haveBufferStorage = hasGLVersion(4, 4) || hasGLExtension("GL_ARB_buffer_storage");
         GLVertexBufferPrivate::haveSyncFences = hasGLVersion(3, 2) || hasGLExtension("GL_ARB_sync");
     }
     GLVertexBufferPrivate::s_indexBuffer.reset();
     GLVertexBufferPrivate::streamingBuffer = std::make_unique<GLVertexBuffer>(GLVertexBuffer::Stream);
 
     if (GLVertexBufferPrivate::haveBufferStorage && GLVertexBufferPrivate::haveSyncFences) {
         if (qgetenv("KWIN_PERSISTENT_VBO") != QByteArrayLiteral("0")) {
             GLVertexBufferPrivate::streamingBuffer->d->persistent = true;
         }
     }
 }
 
 void GLVertexBuffer::cleanup()
 {
     GLVertexBufferPrivate::s_indexBuffer.reset();
     GLVertexBufferPrivate::hasMapBufferRange = false;
     GLVertexBufferPrivate::supportsIndexedQuads = false;
     GLVertexBufferPrivate::streamingBuffer.reset();
 }
 
 GLVertexBuffer *GLVertexBuffer::streamingBuffer()
 {
     return GLVertexBufferPrivate::streamingBuffer.get();
 }
 
 } // namespace