// Copyright (C) 2017 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
#include "glwindow.h"
#include <QImage>
#include <QOpenGLShaderProgram>
#include <QOpenGLContext>
#include <QOpenGLFunctions>
#include <QOpenGLExtraFunctions>
#include <QOpenGLVertexArrayObject>
#include <QtGui/qopengl.h>
#include <QDebug>
#include <QTimer>
#include <math.h>
#ifndef GL_READ_WRITE
#define GL_READ_WRITE 0x88BA
#endif
#ifndef GL_RGBA8
#define GL_RGBA8 0x8058
#endif
#ifndef GL_SHADER_IMAGE_ACCESS_BARRIER_BIT
#define GL_SHADER_IMAGE_ACCESS_BARRIER_BIT 0x00000020
#endif
GLWindow::GLWindow()
{
const float animationStart = 0.0;
const float animationEnd = 10.0;
const float animationLength = 1000;
m_animationGroup = new QSequentialAnimationGroup(this);
m_animationGroup->setLoopCount(-1);
m_animationForward = new QPropertyAnimation(this, QByteArrayLiteral("blurRadius"));
m_animationForward->setStartValue(animationStart);
m_animationForward->setEndValue(animationEnd);
m_animationForward->setDuration(animationLength);
m_animationGroup->addAnimation(m_animationForward);
m_animationBackward = new QPropertyAnimation(this, QByteArrayLiteral("blurRadius"));
m_animationBackward->setStartValue(animationEnd);
m_animationBackward->setEndValue(animationStart);
m_animationBackward->setDuration(animationLength);
m_animationGroup->addAnimation(m_animationBackward);
m_animationGroup->start();
}
GLWindow::~GLWindow()
{
makeCurrent();
delete m_texImageInput;
delete m_texImageProcessed;
delete m_texImageTmp;
delete m_shaderDisplay;
delete m_shaderComputeH;
delete m_shaderComputeV;
delete m_animationGroup;
delete m_animationForward;
delete m_animationBackward;
delete m_vao;
}
void GLWindow::setBlurRadius(float blurRadius)
{
int radius = int(blurRadius);
if (radius != m_blurRadius) {
m_blurRadius = radius;
update();
}
}
void GLWindow::setAnimating(bool animate)
{
m_animate = animate;
if (animate)
m_animationGroup->start();
else
m_animationGroup->stop();
}
void GLWindow::keyPressEvent(QKeyEvent *e)
{
if (e->key() == Qt::Key_Space) { // pause
setAnimating(!m_animate);
}
update();
}
static const char *vsDisplaySource =
"const vec4 vertices[4] = vec4[4] (\n"
" vec4( -1.0, 1.0, 0.0, 1.0),\n"
" vec4( -1.0, -1.0, 0.0, 1.0),\n"
" vec4( 1.0, 1.0, 0.0, 1.0),\n"
" vec4( 1.0, -1.0, 0.0, 1.0)\n"
");\n"
"const vec2 texCoords[4] = vec2[4] (\n"
" vec2( 0.0, 1.0),\n"
" vec2( 0.0, 0.0),\n"
" vec2( 1.0, 1.0),\n"
" vec2( 1.0, 0.0)\n"
");\n"
"out vec2 texCoord;\n"
"uniform mat4 matProjection;\n"
"uniform vec2 imageRatio;\n"
"void main() {\n"
" gl_Position = matProjection * ( vertices[gl_VertexID] * vec4(imageRatio,0,1) );\n"
" texCoord = texCoords[gl_VertexID];\n"
"}\n";
static const char *fsDisplaySource =
"in lowp vec2 texCoord; \n"
"uniform sampler2D samImage; \n"
"layout(location = 0) out lowp vec4 color;\n"
"void main() {\n"
" lowp vec4 texColor = texture(samImage,texCoord);\n"
" color = vec4(texColor.rgb, 1.0);\n"
"}\n";
static const char *csComputeSourceV =
"#define COMPUTEPATCHSIZE 10 // Setting this to 10 to comply with MAX_COMPUTE_WORK_GROUP_INVOCATIONS for both OpenGL and OpenGLES - see QTBUG-79374 \n"
"#define IMGFMT rgba8 \n"
"layout (local_size_x = COMPUTEPATCHSIZE, local_size_y = COMPUTEPATCHSIZE) in;\n"
"layout(binding=0, IMGFMT) uniform readonly highp image2D inputImage; // Use a sampler to improve performance \n"
"layout(binding=1, IMGFMT) uniform writeonly highp image2D resultImage;\n"
"uniform int radius;\n"
"const float cutoff = 2.2;\n"
"float expFactor() { // a function, otherwise MESA produces error: initializer of global variable `expFactor' must be a constant expression\n"
" float sigma = clamp(float(radius) / cutoff,0.02,100.0);\n"
" return 1.0 / (2.0 * sigma * sigma);\n"
"}\n"
"float gaussian(float distance, float expfactor) {\n"
" return exp( -(distance * distance) * expfactor);\n"
"}\n"
"void main() {\n"
" ivec2 imgSize = imageSize(resultImage);\n"
" int x = int(gl_GlobalInvocationID.x);\n"
" int y = int(gl_GlobalInvocationID.y);\n"
" if ( (x >= imgSize.x) || (y >= imgSize.y) ) return;\n"
" vec4 sumPixels = vec4(0.0);\n"
" float sumWeights = 0.0;\n"
" int left = clamp(x - radius, 0, imgSize.x - 1);\n"
" int right = clamp(x + radius, 0, imgSize.x - 1);\n"
" int top = clamp(y - radius, 0, imgSize.y - 1);\n"
" int bottom = clamp(y + radius, 0, imgSize.y - 1);\n"
" float expfactor = expFactor();\n"
" for (int iY = top; iY <= bottom; iY++) {\n"
" float dy = float(abs(iY - y));\n"
" vec4 imgValue = imageLoad(inputImage, ivec2(x,iY));\n"
" float weight = gaussian(dy, expfactor);\n"
" sumWeights += weight;\n"
" sumPixels += (imgValue * weight);\n"
" }\n"
" sumPixels /= sumWeights;\n"
" imageStore(resultImage, ivec2(x,y), sumPixels);\n"
"}\n";
static const char *csComputeSourceH =
"#define COMPUTEPATCHSIZE 10 \n"
"#define IMGFMT rgba8 \n"
"layout (local_size_x = COMPUTEPATCHSIZE, local_size_y = COMPUTEPATCHSIZE) in;\n"
"layout(binding=0, IMGFMT) uniform readonly highp image2D inputImage; // Use a sampler to improve performance \n"
"layout(binding=1, IMGFMT) uniform writeonly highp image2D resultImage;\n"
"uniform int radius;\n"
"const float cutoff = 2.2;\n"
"float expFactor() { // a function, otherwise MESA produces error: initializer of global variable `expFactor' must be a constant expression\n"
" float sigma = clamp(float(radius) / cutoff,0.02,100.0);\n"
" return 1.0 / (2.0 * sigma * sigma);\n"
"}\n"
"float gaussian(float distance, float expfactor) {\n"
" return exp( -(distance * distance) * expfactor);\n"
"}\n"
"void main() {\n"
" ivec2 imgSize = imageSize(resultImage);\n"
" int x = int(gl_GlobalInvocationID.x);\n"
" int y = int(gl_GlobalInvocationID.y);\n"
" if ( (x >= imgSize.x) || (y >= imgSize.y) ) return;\n"
" vec4 sumPixels = vec4(0.0);\n"
" float sumWeights = 0.0;\n"
" int left = clamp(x - radius, 0, imgSize.x - 1);\n"
" int right = clamp(x + radius, 0, imgSize.x - 1);\n"
" int top = clamp(y - radius, 0, imgSize.y - 1);\n"
" int bottom = clamp(y + radius, 0, imgSize.y - 1);\n"
" float expfactor = expFactor();\n"
" for (int iX = left; iX <= right; iX++) {\n"
" float dx = float(abs(iX - x));\n"
" vec4 imgValue = imageLoad(inputImage, ivec2(iX,y));\n"
" float weight = gaussian(dx, expfactor);\n"
" sumWeights += weight;\n"
" sumPixels += (imgValue * weight);\n"
" }\n"
" sumPixels /= sumWeights;\n"
" imageStore(resultImage, ivec2(x,y), sumPixels);\n"
"}\n";
QByteArray versionedShaderCode(const char *src)
{
QByteArray versionedSrc;
if (QOpenGLContext::currentContext()->isOpenGLES())
versionedSrc.append(QByteArrayLiteral("#version 310 es\n"));
else
versionedSrc.append(QByteArrayLiteral("#version 430 core\n"));
versionedSrc.append(src);
return versionedSrc;
}
void computeProjection(int winWidth, int winHeight, int imgWidth, int imgHeight, QMatrix4x4 &outProjection, QSizeF &outQuadSize)
{
float ratioImg = float(imgWidth) / float(imgHeight);
float ratioCanvas = float(winWidth) / float(winHeight);
float correction = ratioImg / ratioCanvas;
float rescaleFactor = 1.0f;
float quadWidth = 1.0f;
float quadHeight = 1.0f;
if (correction < 1.0f) // canvas larger than image -- height = 1.0, vertical black bands
{
quadHeight = 1.0f;
quadWidth = 1.0f * ratioImg;
rescaleFactor = ratioCanvas;
correction = 1.0f / rescaleFactor;
}
else // image larger than canvas -- width = 1.0, horizontal black bands
{
quadWidth = 1.0f;
quadHeight = 1.0f / ratioImg;
correction = 1.0f / ratioCanvas;
}
const float frustumWidth = 1.0f * rescaleFactor;
const float frustumHeight = 1.0f * rescaleFactor * correction;
outProjection = QMatrix4x4();
outProjection.ortho(
-frustumWidth,
frustumWidth,
-frustumHeight,
frustumHeight,
-1.0f,
1.0f);
outQuadSize = QSizeF(quadWidth,quadHeight);
}
void GLWindow::initializeGL()
{
QOpenGLContext *ctx = QOpenGLContext::currentContext();
qDebug() << "Got a "
<< ctx->format().majorVersion()
<< "."
<< ctx->format().minorVersion()
<< ((ctx->format().renderableType() == QSurfaceFormat::OpenGLES) ? (" GLES") : (" GL"))
<< " context";
QImage img(":/Qt-logo-medium.png");
Q_ASSERT(!img.isNull());
delete m_texImageInput;
m_texImageInput = new QOpenGLTexture(img.convertToFormat(QImage::Format_RGBA8888).mirrored());
delete m_texImageTmp;
m_texImageTmp = new QOpenGLTexture(QOpenGLTexture::Target2D);
m_texImageTmp->setFormat(m_texImageInput->format());
m_texImageTmp->setSize(m_texImageInput->width(),m_texImageInput->height());
m_texImageTmp->allocateStorage(QOpenGLTexture::RGBA,QOpenGLTexture::UInt8); // WTF?
delete m_texImageProcessed;
m_texImageProcessed = new QOpenGLTexture(QOpenGLTexture::Target2D);
m_texImageProcessed->setFormat(m_texImageInput->format());
m_texImageProcessed->setSize(m_texImageInput->width(),m_texImageInput->height());
m_texImageProcessed->allocateStorage(QOpenGLTexture::RGBA,QOpenGLTexture::UInt8);
m_texImageProcessed->setMagnificationFilter(QOpenGLTexture::Linear);
m_texImageProcessed->setMinificationFilter(QOpenGLTexture::Linear);
m_texImageProcessed->setWrapMode(QOpenGLTexture::ClampToEdge);
delete m_shaderDisplay;
m_shaderDisplay = new QOpenGLShaderProgram;
// Prepend the correct version directive to the sources. The rest is the
// same, thanks to the common GLSL syntax.
m_shaderDisplay->addShaderFromSourceCode(QOpenGLShader::Vertex, versionedShaderCode(vsDisplaySource));
m_shaderDisplay->addShaderFromSourceCode(QOpenGLShader::Fragment, versionedShaderCode(fsDisplaySource));
m_shaderDisplay->link();
delete m_shaderComputeV;
m_shaderComputeV = new QOpenGLShaderProgram;
m_shaderComputeV->addShaderFromSourceCode(QOpenGLShader::Compute, versionedShaderCode(csComputeSourceV));
m_shaderComputeV->link();
delete m_shaderComputeH;
m_shaderComputeH = new QOpenGLShaderProgram;
m_shaderComputeH->addShaderFromSourceCode(QOpenGLShader::Compute, versionedShaderCode(csComputeSourceH));
m_shaderComputeH->link();
// Create a VAO. Not strictly required for ES 3, but it is for plain OpenGL core context.
m_vao = new QOpenGLVertexArrayObject;
m_vao->create();
}
void GLWindow::resizeGL(int w, int h)
{
computeProjection(w,h,m_texImageInput->width(),m_texImageInput->height(),m_proj,m_quadSize);
}
QSize getWorkGroups(int workGroupSize, const QSize &imageSize)
{
int x = imageSize.width();
x = (x % workGroupSize) ? (x / workGroupSize) + 1 : (x / workGroupSize);
int y = imageSize.height();
y = (y % workGroupSize) ? (y / workGroupSize) + 1 : (y / workGroupSize);
return QSize(x,y);
}
void GLWindow::paintGL()
{
// Now use QOpenGLExtraFunctions instead of QOpenGLFunctions as we want to
// do more than what GL(ES) 2.0 offers.
QOpenGLExtraFunctions *f = QOpenGLContext::currentContext()->extraFunctions();
// Process input image
QSize workGroups = getWorkGroups(10, QSize(m_texImageInput->width(), m_texImageInput->height()));
// Pass 1
f->glBindImageTexture(0, m_texImageInput->textureId(), 0, 0, 0, GL_READ_WRITE, GL_RGBA8);
f->glBindImageTexture(1, m_texImageTmp->textureId(), 0, 0, 0, GL_READ_WRITE, GL_RGBA8);
m_shaderComputeV->bind();
m_shaderComputeV->setUniformValue("radius",m_blurRadius);
f->glDispatchCompute(workGroups.width(),workGroups.height(),1);
f->glMemoryBarrier(GL_SHADER_IMAGE_ACCESS_BARRIER_BIT);
m_shaderComputeV->release();
// Pass 2
f->glBindImageTexture(0, m_texImageTmp->textureId(), 0, 0, 0, GL_READ_WRITE, GL_RGBA8);
f->glBindImageTexture(1, m_texImageProcessed->textureId(), 0, 0, 0, GL_READ_WRITE, GL_RGBA8);
m_shaderComputeH->bind();
m_shaderComputeH->setUniformValue("radius",m_blurRadius);
f->glDispatchCompute(workGroups.width(),workGroups.height(),1);
f->glMemoryBarrier(GL_SHADER_IMAGE_ACCESS_BARRIER_BIT);
m_shaderComputeH->release();
// Compute cleanup
f->glBindImageTexture(0, 0, 0, 0, 0, GL_READ_WRITE, GL_RGBA8);
f->glBindImageTexture(1, 0, 0, 0, 0, GL_READ_WRITE, GL_RGBA8);
// Display processed image
f->glClearColor(0, 0, 0, 1);
f->glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
m_texImageProcessed->bind(0);
m_shaderDisplay->bind();
m_shaderDisplay->setUniformValue("matProjection",m_proj);
m_shaderDisplay->setUniformValue("imageRatio",m_quadSize);
m_shaderDisplay->setUniformValue("samImage",0);
m_vao->bind();
f->glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
m_vao->release();
m_shaderDisplay->release();
m_texImageProcessed->release(0);
}