qtbase/src/gui/opengl/qopengltextureblitter.cpp

395 lines
12 KiB
C++

/****************************************************************************
**
** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/legal
**
** This file is part of the QtGui module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
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** accordance with the commercial license agreement provided with the
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** conditions see http://qt.digia.com/licensing. For further information
** use the contact form at http://qt.digia.com/contact-us.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file. Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
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** rights. These rights are described in the Digia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3.0 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file. Please review the following information to
** ensure the GNU General Public License version 3.0 requirements will be
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****************************************************************************/
#include "qopengltextureblitter_p.h"
#include <QtGui/QOpenGLBuffer>
#include <QtGui/QOpenGLShaderProgram>
#include <QtGui/QOpenGLVertexArrayObject>
#include <QtGui/QOpenGLContext>
#include <QtGui/QOpenGLFunctions>
QT_BEGIN_NAMESPACE
static const char vertex_shader150[] =
"#version 150 core\n"
"in vec3 vertexCoord;"
"in vec2 textureCoord;"
"out vec2 uv;"
"uniform mat4 vertexTransform;"
"uniform mat3 textureTransform;"
"void main() {"
" uv = (textureTransform * vec3(textureCoord,1.0)).xy;"
" gl_Position = vertexTransform * vec4(vertexCoord,1.0);"
"}";
static const char fragment_shader150[] =
"#version 150 core\n"
"in vec2 uv;"
"out vec4 fragcolor;"
"uniform sampler2D textureSampler;"
"uniform bool swizzle;"
"void main() {"
" vec4 tmpFragColor = texture(textureSampler, uv);"
" fragcolor = swizzle ? tmpFragColor.bgra : tmpFragColor;"
"}";
static const char vertex_shader[] =
"attribute highp vec3 vertexCoord;"
"attribute highp vec2 textureCoord;"
"varying highp vec2 uv;"
"uniform highp mat4 vertexTransform;"
"uniform highp mat3 textureTransform;"
"void main() {"
" uv = (textureTransform * vec3(textureCoord,1.0)).xy;"
" gl_Position = vertexTransform * vec4(vertexCoord,1.0);"
"}";
static const char fragment_shader[] =
"varying highp vec2 uv;"
"uniform sampler2D textureSampler;"
"uniform bool swizzle;"
"void main() {"
" highp vec4 tmpFragColor = texture2D(textureSampler,uv);"
" gl_FragColor = swizzle ? tmpFragColor.bgra : tmpFragColor;"
"}";
static const GLfloat vertex_buffer_data[] = {
-1,-1, 0,
-1, 1, 0,
1,-1, 0,
-1, 1, 0,
1,-1, 0,
1, 1, 0
};
static const GLfloat texture_buffer_data[] = {
0, 0,
0, 1,
1, 0,
0, 1,
1, 0,
1, 1
};
class TextureBinder
{
public:
TextureBinder(GLuint textureId)
{
QOpenGLContext::currentContext()->functions()->glBindTexture(GL_TEXTURE_2D, textureId);
}
~TextureBinder()
{
QOpenGLContext::currentContext()->functions()->glBindTexture(GL_TEXTURE_2D, 0);
}
};
class QOpenGLTextureBlitterPrivate
{
public:
enum TextureMatrixUniform {
User,
Identity,
IdentityFlipped
};
QOpenGLTextureBlitterPrivate()
: program(0)
, vertexCoordAttribPos(0)
, vertexTransformUniformPos(0)
, textureCoordAttribPos(0)
, textureTransformUniformPos(0)
, swizzle(false)
, swizzleOld(false)
, textureMatrixUniformState(User)
, vao(new QOpenGLVertexArrayObject())
{ }
void blit(GLuint texture, const QMatrix4x4 &vertexTransform, const QMatrix3x3 &textureTransform);
void blit(GLuint texture, const QMatrix4x4 &vertexTransform, QOpenGLTextureBlitter::Origin origin);
void prepareProgram(const QMatrix4x4 &vertexTransform)
{
vertexBuffer.bind();
program->setAttributeBuffer(vertexCoordAttribPos, GL_FLOAT, 0, 3, 0);
program->enableAttributeArray(vertexCoordAttribPos);
vertexBuffer.release();
program->setUniformValue(vertexTransformUniformPos, vertexTransform);
textureBuffer.bind();
program->setAttributeBuffer(textureCoordAttribPos, GL_FLOAT, 0, 2, 0);
program->enableAttributeArray(textureCoordAttribPos);
textureBuffer.release();
if (swizzle != swizzleOld) {
program->setUniformValue(swizzleUniformPos, swizzle);
swizzleOld = swizzle;
}
}
QOpenGLBuffer vertexBuffer;
QOpenGLBuffer textureBuffer;
QScopedPointer<QOpenGLShaderProgram> program;
GLuint vertexCoordAttribPos;
GLuint vertexTransformUniformPos;
GLuint textureCoordAttribPos;
GLuint textureTransformUniformPos;
GLuint swizzleUniformPos;
bool swizzle;
bool swizzleOld;
TextureMatrixUniform textureMatrixUniformState;
QScopedPointer<QOpenGLVertexArrayObject> vao;
};
void QOpenGLTextureBlitterPrivate::blit(GLuint texture,
const QMatrix4x4 &vertexTransform,
const QMatrix3x3 &textureTransform)
{
TextureBinder binder(texture);
prepareProgram(vertexTransform);
program->setUniformValue(textureTransformUniformPos, textureTransform);
textureMatrixUniformState = User;
QOpenGLContext::currentContext()->functions()->glDrawArrays(GL_TRIANGLES, 0, 6);
}
void QOpenGLTextureBlitterPrivate::blit(GLuint texture,
const QMatrix4x4 &vertexTransform,
QOpenGLTextureBlitter::Origin origin)
{
TextureBinder binder(texture);
prepareProgram(vertexTransform);
if (origin == QOpenGLTextureBlitter::OriginTopLeft) {
if (textureMatrixUniformState != IdentityFlipped) {
QMatrix3x3 flipped;
flipped(1,1) = -1;
flipped(1,2) = 1;
program->setUniformValue(textureTransformUniformPos, flipped);
textureMatrixUniformState = IdentityFlipped;
}
} else if (textureMatrixUniformState != Identity) {
program->setUniformValue(textureTransformUniformPos, QMatrix3x3());
textureMatrixUniformState = Identity;
}
QOpenGLContext::currentContext()->functions()->glDrawArrays(GL_TRIANGLES, 0, 6);
}
QOpenGLTextureBlitter::QOpenGLTextureBlitter()
: d_ptr(new QOpenGLTextureBlitterPrivate)
{
}
QOpenGLTextureBlitter::~QOpenGLTextureBlitter()
{
}
bool QOpenGLTextureBlitter::create()
{
QOpenGLContext *currentContext = QOpenGLContext::currentContext();
if (!currentContext)
return false;
Q_D(QOpenGLTextureBlitter);
d->vao->create();
d->vao->bind();
if (d->program)
return true;
d->program.reset(new QOpenGLShaderProgram());
QSurfaceFormat format = currentContext->format();
if (format.profile() == QSurfaceFormat::CoreProfile && format.version() >= qMakePair(3,2)) {
d->program->addShaderFromSourceCode(QOpenGLShader::Vertex, vertex_shader150);
d->program->addShaderFromSourceCode(QOpenGLShader::Fragment, fragment_shader150);
} else {
d->program->addShaderFromSourceCode(QOpenGLShader::Vertex, vertex_shader);
d->program->addShaderFromSourceCode(QOpenGLShader::Fragment, fragment_shader);
}
d->program->link();
if (!d->program->isLinked()) {
qWarning() << Q_FUNC_INFO << "Could not link shader program:\n" << d->program->log();
return false;
}
d->program->bind();
d->vertexBuffer.create();
d->vertexBuffer.bind();
d->vertexBuffer.allocate(vertex_buffer_data, sizeof(vertex_buffer_data));
d->vertexBuffer.release();
d->textureBuffer.create();
d->textureBuffer.bind();
d->textureBuffer.allocate(texture_buffer_data, sizeof(texture_buffer_data));
d->textureBuffer.release();
d->vertexCoordAttribPos = d->program->attributeLocation("vertexCoord");
d->vertexTransformUniformPos = d->program->uniformLocation("vertexTransform");
d->textureCoordAttribPos = d->program->attributeLocation("textureCoord");
d->textureTransformUniformPos = d->program->uniformLocation("textureTransform");
d->swizzleUniformPos = d->program->uniformLocation("swizzle");
d->program->setUniformValue(d->swizzleUniformPos,false);
d->vao->release();
return true;
}
bool QOpenGLTextureBlitter::isCreated() const
{
Q_D(const QOpenGLTextureBlitter);
return d->program;
}
void QOpenGLTextureBlitter::destroy()
{
Q_D(QOpenGLTextureBlitter);
d->program.reset();
d->vertexBuffer.destroy();
d->textureBuffer.destroy();
d->vao.reset();
}
void QOpenGLTextureBlitter::bind()
{
Q_D(QOpenGLTextureBlitter);
d->vao->bind();
d->program->bind();
d->vertexBuffer.bind();
d->program->setAttributeBuffer(d->vertexCoordAttribPos, GL_FLOAT, 0, 3, 0);
d->program->enableAttributeArray(d->vertexCoordAttribPos);
d->vertexBuffer.release();
d->textureBuffer.bind();
d->program->setAttributeBuffer(d->textureCoordAttribPos, GL_FLOAT, 0, 2, 0);
d->program->enableAttributeArray(d->textureCoordAttribPos);
d->textureBuffer.release();
}
void QOpenGLTextureBlitter::release()
{
Q_D(QOpenGLTextureBlitter);
d->program->release();
d->vao->release();
}
void QOpenGLTextureBlitter::setSwizzleRB(bool swizzle)
{
Q_D(QOpenGLTextureBlitter);
d->swizzle = swizzle;
}
void QOpenGLTextureBlitter::blit(GLuint texture,
const QMatrix4x4 &targetTransform,
Origin sourceOrigin)
{
Q_D(QOpenGLTextureBlitter);
d->blit(texture,targetTransform, sourceOrigin);
}
void QOpenGLTextureBlitter::blit(GLuint texture,
const QMatrix4x4 &targetTransform,
const QMatrix3x3 &sourceTransform)
{
Q_D(QOpenGLTextureBlitter);
d->blit(texture, targetTransform, sourceTransform);
}
QMatrix4x4 QOpenGLTextureBlitter::targetTransform(const QRectF &target,
const QRect &viewport)
{
qreal x_scale = target.width() / viewport.width();
qreal y_scale = target.height() / viewport.height();
const QPointF relative_to_viewport = target.topLeft() - viewport.topLeft();
qreal x_translate = x_scale - 1 + ((relative_to_viewport.x() / viewport.width()) * 2);
qreal y_translate = -y_scale + 1 - ((relative_to_viewport.y() / viewport.height()) * 2);
QMatrix4x4 matrix;
matrix(0,3) = x_translate;
matrix(1,3) = y_translate;
matrix(0,0) = x_scale;
matrix(1,1) = y_scale;
return matrix;
}
QMatrix3x3 QOpenGLTextureBlitter::sourceTransform(const QRectF &subTexture,
const QSize &textureSize,
Origin origin)
{
qreal x_scale = subTexture.width() / textureSize.width();
qreal y_scale = subTexture.height() / textureSize.height();
const QPointF topLeft = subTexture.topLeft();
qreal x_translate = topLeft.x() / textureSize.width();
qreal y_translate = topLeft.y() / textureSize.height();
if (origin == OriginTopLeft) {
y_scale = -y_scale;
y_translate = 1 - y_translate;
}
QMatrix3x3 matrix;
matrix(0,2) = x_translate;
matrix(1,2) = y_translate;
matrix(0,0) = x_scale;
matrix(1,1) = y_scale;
return matrix;
}
QT_END_NAMESPACE