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Merge branch 'jb37220' into 'mer-5.6'
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MER: eglfs: Allow scaling down the window surface

Adapted from commit 0061edc from mer-stable branch.

See merge request !17
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@sletta
sletta committed Jan 10, 2017
2 parents abd497e + 35b44c0 commit 975ec23
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Showing 2 changed files with 255 additions and 1 deletion.
242 changes: 241 additions & 1 deletion src/plugins/platforms/eglfs/qeglfscontext.cpp
View file
Expand Up @@ -40,15 +40,228 @@
#include "qeglfswindow.h"
#include "qeglfshooks.h"
#include "qeglfscursor.h"
#include "qeglfsintegration.h"

#include <QtPlatformSupport/private/qeglpbuffer_p.h>
#include <QtGui/QSurface>
#include <QtDebug>
#include <QOpenGLFramebufferObject>
#include <QOpenGLShaderProgram>

QT_BEGIN_NAMESPACE


class Blitter : public QOpenGLFunctions
{
public:
Blitter(QEglFSContext *context)
: m_context(context)
{
initializeOpenGLFunctions();
m_blitProgram = new QOpenGLShaderProgram();
m_blitProgram->addShaderFromSourceCode(QOpenGLShader::Vertex, "attribute vec4 position;\n\
attribute vec2 texCoords;\n\
varying vec2 outTexCoords;\n\
void main()\n\
{\n\
gl_Position = position;\n\
outTexCoords = texCoords;\n\
}");
m_blitProgram->addShaderFromSourceCode(QOpenGLShader::Fragment, "varying highp vec2 outTexCoords;\n\
uniform sampler2D texture;\n\
void main()\n\
{\n\
gl_FragColor = texture2D(texture, outTexCoords);\n\
}");

m_blitProgram->bindAttributeLocation("position", 0);
m_blitProgram->bindAttributeLocation("texCoords", 1);

if (!m_blitProgram->link()) {
qDebug() << "Shader Program link failed.";
qDebug() << m_blitProgram->log();
}
}
~Blitter()
{
delete m_blitProgram;
}
void blit(QOpenGLFramebufferObject *fbo, const QSize &size)
{
glViewport(0, 0, size.width(), size.height());

glDisable(GL_DEPTH_TEST);
glDisable(GL_BLEND);
glDisable(GL_CULL_FACE);
glDisable(GL_SCISSOR_TEST);
glDepthMask(GL_FALSE);
glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);

m_context->m_useNativeDefaultFbo = true;
glBindFramebuffer(GL_FRAMEBUFFER, 0);
m_context->m_useNativeDefaultFbo = false;

static const GLfloat squareVertices[] = {
-1.f, -1.f,
1.0f, -1.f,
-1.f, 1.0f,
1.0f, 1.0f
};

static const GLfloat textureVertices[] = {
0.0f, 0.0f,
1.0f, 0.0f,
0.0f, 1.0f,
1.0f, 1.0f,
};

glBindBuffer(GL_ARRAY_BUFFER, 0);
m_blitProgram->bind();

m_blitProgram->enableAttributeArray(0);
m_blitProgram->enableAttributeArray(1);
m_blitProgram->setAttributeArray(1, textureVertices, 2);

glActiveTexture(GL_TEXTURE0);

//Draw Content
m_blitProgram->setAttributeArray(0, squareVertices, 2);
glBindTexture(GL_TEXTURE_2D, fbo->texture());
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);

//Cleanup
m_blitProgram->disableAttributeArray(0);
m_blitProgram->disableAttributeArray(1);
}

QOpenGLShaderProgram *m_blitProgram;
QEglFSContext *m_context;
};

#define STATE_GUARD_VERTEX_ATTRIB_COUNT 2

class StateGuard
{
public:
StateGuard() {
QOpenGLFunctions glFuncs(QOpenGLContext::currentContext());

glGetIntegerv(GL_CURRENT_PROGRAM, (GLint *) &m_program);
glGetIntegerv(GL_ACTIVE_TEXTURE, (GLint *) &m_activeTextureUnit);
glGetIntegerv(GL_TEXTURE_BINDING_2D, (GLint *) &m_texture);
glGetIntegerv(GL_FRAMEBUFFER_BINDING, (GLint *) &m_fbo);
glGetIntegerv(GL_VIEWPORT, m_viewport);
glGetIntegerv(GL_DEPTH_WRITEMASK, &m_depthWriteMask);
glGetIntegerv(GL_COLOR_WRITEMASK, m_colorWriteMask);
m_blend = glIsEnabled(GL_BLEND);
m_depth = glIsEnabled(GL_DEPTH_TEST);
m_cull = glIsEnabled(GL_CULL_FACE);
m_scissor = glIsEnabled(GL_SCISSOR_TEST);
for (int i = 0; i < STATE_GUARD_VERTEX_ATTRIB_COUNT; ++i) {
glFuncs.glGetVertexAttribiv(i, GL_VERTEX_ATTRIB_ARRAY_ENABLED, (GLint *) &m_vertexAttribs[i].enabled);
glFuncs.glGetVertexAttribiv(i, GL_VERTEX_ATTRIB_ARRAY_BUFFER_BINDING, (GLint *) &m_vertexAttribs[i].arrayBuffer);
glFuncs.glGetVertexAttribiv(i, GL_VERTEX_ATTRIB_ARRAY_SIZE, &m_vertexAttribs[i].size);
glFuncs.glGetVertexAttribiv(i, GL_VERTEX_ATTRIB_ARRAY_STRIDE, &m_vertexAttribs[i].stride);
glFuncs.glGetVertexAttribiv(i, GL_VERTEX_ATTRIB_ARRAY_TYPE, (GLint *) &m_vertexAttribs[i].type);
glFuncs.glGetVertexAttribiv(i, GL_VERTEX_ATTRIB_ARRAY_NORMALIZED, (GLint *) &m_vertexAttribs[i].normalized);
glFuncs.glGetVertexAttribPointerv(i, GL_VERTEX_ATTRIB_ARRAY_POINTER, &m_vertexAttribs[i].pointer);
}
glGetTexParameteriv(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, (GLint *) &m_minFilter);
glGetTexParameteriv(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, (GLint *) &m_magFilter);
glGetTexParameteriv(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, (GLint *) &m_wrapS);
glGetTexParameteriv(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, (GLint *) &m_wrapT);
}

~StateGuard() {
QOpenGLFunctions glFuncs(QOpenGLContext::currentContext());

glFuncs.glUseProgram(m_program);
glActiveTexture(m_activeTextureUnit);
glBindTexture(GL_TEXTURE_2D, m_texture);
glFuncs.glBindFramebuffer(GL_FRAMEBUFFER, m_fbo);
glViewport(m_viewport[0], m_viewport[1], m_viewport[2], m_viewport[3]);
glDepthMask(m_depthWriteMask);
glColorMask(m_colorWriteMask[0], m_colorWriteMask[1], m_colorWriteMask[2], m_colorWriteMask[3]);
if (m_blend)
glEnable(GL_BLEND);
if (m_depth)
glEnable(GL_DEPTH_TEST);
if (m_cull)
glEnable(GL_CULL_FACE);
if (m_scissor)
glEnable(GL_SCISSOR_TEST);
for (int i = 0; i < STATE_GUARD_VERTEX_ATTRIB_COUNT; ++i) {
if (m_vertexAttribs[i].enabled)
glFuncs.glEnableVertexAttribArray(i);
GLuint prevBuf;
glGetIntegerv(GL_ARRAY_BUFFER_BINDING, (GLint *) &prevBuf);
glFuncs.glBindBuffer(GL_ARRAY_BUFFER, m_vertexAttribs[i].arrayBuffer);
glFuncs.glVertexAttribPointer(i, m_vertexAttribs[i].size, m_vertexAttribs[i].type,
m_vertexAttribs[i].normalized, m_vertexAttribs[i].stride,
m_vertexAttribs[i].pointer);
glFuncs.glBindBuffer(GL_ARRAY_BUFFER, prevBuf);
}
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, m_minFilter);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, m_magFilter);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, m_wrapS);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, m_wrapT);
}

private:
GLuint m_program;
GLenum m_activeTextureUnit;
GLuint m_texture;
GLuint m_fbo;
GLint m_depthWriteMask;
GLint m_colorWriteMask[4];
GLboolean m_blend;
GLboolean m_depth;
GLboolean m_cull;
GLboolean m_scissor;
GLint m_viewport[4];
struct VertexAttrib {
bool enabled;
GLuint arrayBuffer;
GLint size;
GLint stride;
GLenum type;
bool normalized;
void *pointer;
} m_vertexAttribs[STATE_GUARD_VERTEX_ATTRIB_COUNT];
GLenum m_minFilter;
GLenum m_magFilter;
GLenum m_wrapS;
GLenum m_wrapT;
};

QEglFSContext::QEglFSContext(const QSurfaceFormat &format, QPlatformOpenGLContext *share, EGLDisplay display,
EGLConfig *config, const QVariant &nativeHandle)
: QEGLPlatformContext(format, share, display, config, nativeHandle,
qt_egl_device_integration()->supportsSurfacelessContexts() ? Flags(0) : QEGLPlatformContext::NoSurfaceless),
m_tempWindow(0)
m_tempWindow(0),
m_useNativeDefaultFbo(false),
m_fbo(0),
m_blitter(0)
{
m_scale = qgetenv("QT_QPA_EGLFS_SCALE").toInt();
}

QEglFSContext::~QEglFSContext()
{
delete m_blitter;
delete m_fbo;
}

bool QEglFSContext::makeCurrent(QPlatformSurface *surface)
{
bool success = QEGLPlatformContext::makeCurrent(surface);

if (m_scale > 1)
fbo(surface)->bind();

return success;
}

EGLSurface QEglFSContext::eglSurfaceForPlatformSurface(QPlatformSurface *surface)
Expand Down Expand Up @@ -98,6 +311,16 @@ void QEglFSContext::runGLChecks()

void QEglFSContext::swapBuffers(QPlatformSurface *surface)
{
if (m_scale > 1) {
// Must save & restore all state. Applications are usually not prepared
// for random context state changes in a swapBuffers() call.
StateGuard stateGuard;

if (!m_blitter)
m_blitter = new Blitter(this);
m_blitter->blit(m_fbo, surface->surface()->size() / m_scale);
}

// draw the cursor
if (surface->surface()->surfaceClass() == QSurface::Window) {
QPlatformWindow *window = static_cast<QPlatformWindow *>(surface);
Expand All @@ -110,4 +333,21 @@ void QEglFSContext::swapBuffers(QPlatformSurface *surface)
qt_egl_device_integration()->presentBuffer(surface);
}

QOpenGLFramebufferObject *QEglFSContext::fbo(QPlatformSurface *surface) const
{
QSize size = surface->surface()->size();
if (!m_fbo || m_fbo->size() != size) {
delete m_fbo;
m_fbo = new QOpenGLFramebufferObject(size);
}
return m_fbo;
}

GLuint QEglFSContext::defaultFramebufferObject(QPlatformSurface *surface) const
{
if (m_useNativeDefaultFbo || m_scale <= 1)
return 0;
return fbo(surface)->handle();
}

QT_END_NAMESPACE
14 changes: 14 additions & 0 deletions src/plugins/platforms/eglfs/qeglfscontext.h
View file
Expand Up @@ -40,19 +40,33 @@

QT_BEGIN_NAMESPACE

class QOpenGLFramebufferObject;
class Blitter;

class Q_EGLFS_EXPORT QEglFSContext : public QEGLPlatformContext
{
public:
QEglFSContext(const QSurfaceFormat &format, QPlatformOpenGLContext *share, EGLDisplay display,
EGLConfig *config, const QVariant &nativeHandle);
~QEglFSContext();
bool makeCurrent(QPlatformSurface *surface) Q_DECL_OVERRIDE;
EGLSurface eglSurfaceForPlatformSurface(QPlatformSurface *surface) Q_DECL_OVERRIDE;
EGLSurface createTemporaryOffscreenSurface() Q_DECL_OVERRIDE;
void destroyTemporaryOffscreenSurface(EGLSurface surface) Q_DECL_OVERRIDE;
void runGLChecks() Q_DECL_OVERRIDE;
void swapBuffers(QPlatformSurface *surface) Q_DECL_OVERRIDE;
GLuint defaultFramebufferObject(QPlatformSurface *surface) const Q_DECL_OVERRIDE;

private:
QOpenGLFramebufferObject *fbo(QPlatformSurface *surface) const;

EGLNativeWindowType m_tempWindow;
bool m_useNativeDefaultFbo;
mutable QOpenGLFramebufferObject *m_fbo;
Blitter *m_blitter;
int m_scale;

friend class Blitter;
};

QT_END_NAMESPACE
Expand Down

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