Merge remote-tracking branch 'origin/5.12' into dev

Change-Id: I6083c3e61b7dbe188f83676f7e7bb268e5ccf2f3

4 files changed, 63 insertions, 47 deletions

diff --git a/src/gui/opengl/qopenglbuffer.cpp b/src/gui/opengl/qopenglbuffer.cpp
index 69c2baa8d9..000494244d 100644
--- a/src/gui/opengl/qopenglbuffer.cpp
+++ b/src/gui/opengl/qopenglbuffer.cpp
@@ -43,6 +43,10 @@
 #include "qopenglbuffer.h"
 #include <private/qopenglextensions_p.h>
 
+#ifndef GL_CONTEXT_LOST
+#define GL_CONTEXT_LOST                   0x0507
+#endif
+
 QT_BEGIN_NAMESPACE
 
 /*!
@@ -346,7 +350,14 @@ bool QOpenGLBuffer::read(int offset, void *data, int count)
     Q_D(QOpenGLBuffer);
     if (!d->funcs->hasOpenGLFeature(QOpenGLFunctions::Buffers) || !d->guard->id())
         return false;
-    while (d->funcs->glGetError() != GL_NO_ERROR) ; // Clear error state.
+
+    while (true) { // Clear error state.
+        GLenum error = d->funcs->glGetError();
+        if (error == GL_NO_ERROR)
+            break;
+        if (error == GL_CONTEXT_LOST)
+            return false;
+    };
     d->funcs->glGetBufferSubData(d->type, offset, count, data);
     return d->funcs->glGetError() == GL_NO_ERROR;
 #else
diff --git a/src/gui/opengl/qopengldebug.cpp b/src/gui/opengl/qopengldebug.cpp
index f6c3af37dd..7072db5af4 100644
--- a/src/gui/opengl/qopengldebug.cpp
+++ b/src/gui/opengl/qopengldebug.cpp
@@ -100,6 +100,10 @@ QT_BEGIN_NAMESPACE
 
     \endcode
 
+    If you try to clear the error stack, make sure not just keep going until
+    GL_NO_ERROR is returned but also break on GL_CONTEXT_LOST as that error
+    value will keep repeating.
+
     There are also many other information we are interested in (as application
     developers), for instance performance issues, or warnings about using
     deprecated APIs. Those kind of messages are not reported through the
diff --git a/src/gui/opengl/qopenglprogrambinarycache.cpp b/src/gui/opengl/qopenglprogrambinarycache.cpp
index f2d093ebed..0f03101329 100644
--- a/src/gui/opengl/qopenglprogrambinarycache.cpp
+++ b/src/gui/opengl/qopenglprogrambinarycache.cpp
@@ -54,6 +54,10 @@ QT_BEGIN_NAMESPACE
 
 Q_DECLARE_LOGGING_CATEGORY(DBG_SHADER_CACHE)
 
+#ifndef GL_CONTEXT_LOST
+#define GL_CONTEXT_LOST                   0x0507
+#endif
+
 #ifndef GL_PROGRAM_BINARY_LENGTH
 #define GL_PROGRAM_BINARY_LENGTH          0x8741
 #endif
@@ -161,7 +165,11 @@ bool QOpenGLProgramBinaryCache::verifyHeader(const QByteArray &buf) const
 bool QOpenGLProgramBinaryCache::setProgramBinary(uint programId, uint blobFormat, const void *p, uint blobSize)
 {
     QOpenGLExtraFunctions *funcs = QOpenGLContext::currentContext()->extraFunctions();
-    while (funcs->glGetError() != GL_NO_ERROR) { }
+    while (true) {
+        GLenum error = funcs->glGetError();
+        if (error == GL_NO_ERROR || error == GL_CONTEXT_LOST)
+            break;
+    }
     funcs->glProgramBinary(programId, blobFormat, p, blobSize);
 
     GLenum err = funcs->glGetError();
@@ -337,7 +345,11 @@ void QOpenGLProgramBinaryCache::save(const QByteArray &cacheKey, uint programId)
 
     QOpenGLExtraFunctions *funcs = QOpenGLContext::currentContext()->extraFunctions();
     GLint blobSize = 0;
-    while (funcs->glGetError() != GL_NO_ERROR) { }
+    while (true) {
+        GLenum error = funcs->glGetError();
+        if (error == GL_NO_ERROR || error == GL_CONTEXT_LOST)
+            break;
+    }
     funcs->glGetProgramiv(programId, GL_PROGRAM_BINARY_LENGTH, &blobSize);
 
     const int headerSize = FULL_HEADER_SIZE(info.glvendor.size() + info.glrenderer.size() + info.glversion.size());
diff --git a/src/gui/opengl/qopenglshaderprogram.cpp b/src/gui/opengl/qopenglshaderprogram.cpp
index 6d7aecac6f..c39177080d 100644
--- a/src/gui/opengl/qopenglshaderprogram.cpp
+++ b/src/gui/opengl/qopenglshaderprogram.cpp
@@ -39,7 +39,7 @@
 
 #include "qopenglshaderprogram.h"
 #include "qopenglprogrambinarycache_p.h"
-#include "qopenglfunctions.h"
+#include "qopenglextrafunctions.h"
 #include "private/qopenglcontext_p.h"
 #include <QtCore/private/qobject_p.h>
 #include <QtCore/qdebug.h>
@@ -170,13 +170,13 @@ QT_BEGIN_NAMESPACE
     \value Vertex Vertex shader written in the OpenGL Shading Language (GLSL).
     \value Fragment Fragment shader written in the OpenGL Shading Language (GLSL).
     \value Geometry Geometry shaders written in the OpenGL Shading Language (GLSL)
-           based on the OpenGL core feature (requires OpenGL >= 3.2).
+           (requires OpenGL >= 3.2 or OpenGL ES >= 3.2).
     \value TessellationControl Tessellation control shaders written in the OpenGL
-           shading language (GLSL), based on the core feature (requires OpenGL >= 4.0).
+           shading language (GLSL) (requires OpenGL >= 4.0 or OpenGL ES >= 3.2).
     \value TessellationEvaluation Tessellation evaluation shaders written in the OpenGL
-           shading language (GLSL), based on the core feature (requires OpenGL >= 4.0).
-    \value Compute Compute shaders written in the OpenGL shading language (GLSL),
-           based on the core feature (requires OpenGL >= 4.3).
+           shading language (GLSL) (requires OpenGL >= 4.0 or OpenGL ES >= 3.2).
+    \value Compute Compute shaders written in the OpenGL shading language (GLSL)
+           (requires OpenGL >= 4.3 or OpenGL ES >= 3.1).
 */
 
 Q_LOGGING_CATEGORY(DBG_SHADER_CACHE, "qt.opengl.diskcache")
@@ -223,26 +223,18 @@ static inline bool isFormatGLES(const QSurfaceFormat &f)
 
 static inline bool supportsGeometry(const QSurfaceFormat &f)
 {
-#ifndef QT_OPENGL_ES_2
-    if (!isFormatGLES(f))
-        return (f.version() >= qMakePair<int, int>(3, 2));
-    else
-        return false;
-#else
-    Q_UNUSED(f);
-    return false;
-#endif
+    return f.version() >= qMakePair(3, 2);
 }
 
 static inline bool supportsCompute(const QSurfaceFormat &f)
 {
 #ifndef QT_OPENGL_ES_2
     if (!isFormatGLES(f))
-        return (f.version() >= qMakePair<int, int>(4, 3));
+        return f.version() >= qMakePair(4, 3);
     else
-        return (f.version() >= qMakePair<int, int>(3, 1));
+        return f.version() >= qMakePair(3, 1);
 #else
-    return (f.version() >= qMakePair<int, int>(3, 1));
+    return f.version() >= qMakePair(3, 1);
 #endif
 }
 
@@ -250,12 +242,11 @@ static inline bool supportsTessellation(const QSurfaceFormat &f)
 {
 #ifndef QT_OPENGL_ES_2
     if (!isFormatGLES(f))
-        return (f.version() >= qMakePair<int, int>(4, 0));
+        return f.version() >= qMakePair(4, 0);
     else
-        return false;
+        return f.version() >= qMakePair(3, 2);
 #else
-    Q_UNUSED(f);
-    return false;
+    return f.version() >= qMakePair(3, 2);
 #endif
 }
 
@@ -267,7 +258,7 @@ public:
         : shaderGuard(0)
         , shaderType(type)
         , compiled(false)
-        , glfuncs(new QOpenGLFunctions(ctx))
+        , glfuncs(new QOpenGLExtraFunctions(ctx))
         , supportsGeometryShaders(false)
         , supportsTessellationShaders(false)
         , supportsComputeShaders(false)
@@ -286,7 +277,7 @@ public:
     bool compiled;
     QString log;
 
-    QOpenGLFunctions *glfuncs;
+    QOpenGLExtraFunctions *glfuncs;
 
     // Support for geometry shaders
     bool supportsGeometryShaders;
@@ -802,7 +793,7 @@ public:
         , linked(false)
         , inited(false)
         , removingShaders(false)
-        , glfuncs(new QOpenGLFunctions)
+        , glfuncs(new QOpenGLExtraFunctions)
 #ifndef QT_OPENGL_ES_2
         , tessellationFuncs(0)
 #endif
@@ -820,10 +811,9 @@ public:
     QList<QOpenGLShader *> shaders;
     QList<QOpenGLShader *> anonShaders;
 
-    QOpenGLFunctions *glfuncs;
-
+    QOpenGLExtraFunctions *glfuncs;
 #ifndef QT_OPENGL_ES_2
-    // Tessellation shader support
+    // for tessellation features not in GLES 3.2
     QOpenGLFunctions_4_0_Core *tessellationFuncs;
 #endif
 
@@ -913,10 +903,7 @@ bool QOpenGLShaderProgram::init()
     d->glfuncs->initializeOpenGLFunctions();
 
 #ifndef QT_OPENGL_ES_2
-    // Resolve OpenGL 4 functions for tessellation shader support
-    QSurfaceFormat format = context->format();
-    if (!context->isOpenGLES()
-        && format.version() >= qMakePair<int, int>(4, 0)) {
+    if (!context->isOpenGLES() && context->format().version() >= qMakePair(4, 0)) {
         d->tessellationFuncs = context->versionFunctions<QOpenGLFunctions_4_0_Core>();
         d->tessellationFuncs->initializeOpenGLFunctions();
     }
@@ -3508,13 +3495,8 @@ int QOpenGLShaderProgram::maxGeometryOutputVertices() const
 */
 void QOpenGLShaderProgram::setPatchVertexCount(int count)
 {
-#ifndef QT_OPENGL_ES_2
     Q_D(QOpenGLShaderProgram);
-    if (d->tessellationFuncs)
-        d->tessellationFuncs->glPatchParameteri(GL_PATCH_VERTICES, count);
-#else
-    Q_UNUSED(count);
-#endif
+    d->glfuncs->glPatchParameteri(GL_PATCH_VERTICES, count);
 }
 
 /*!
@@ -3527,15 +3509,10 @@ void QOpenGLShaderProgram::setPatchVertexCount(int count)
 */
 int QOpenGLShaderProgram::patchVertexCount() const
 {
-#ifndef QT_OPENGL_ES_2
     int patchVertices = 0;
     Q_D(const QOpenGLShaderProgram);
-    if (d->tessellationFuncs)
-        d->tessellationFuncs->glGetIntegerv(GL_PATCH_VERTICES, &patchVertices);
+    d->glfuncs->glGetIntegerv(GL_PATCH_VERTICES, &patchVertices);
     return patchVertices;
-#else
-    return 0;
-#endif
 }
 
 /*!
@@ -3553,6 +3530,9 @@ int QOpenGLShaderProgram::patchVertexCount() const
     function when needed, as QOpenGLShaderProgram will not apply this for
     you. This is purely a convenience function.
 
+    \note This function is only available with OpenGL >= 4.0 and is not supported
+    with OpenGL ES 3.2.
+
     \sa defaultOuterTessellationLevels(), setDefaultInnerTessellationLevels()
 */
 void QOpenGLShaderProgram::setDefaultOuterTessellationLevels(const QVector<float> &levels)
@@ -3590,6 +3570,9 @@ void QOpenGLShaderProgram::setDefaultOuterTessellationLevels(const QVector<float
     \note This returns the global OpenGL state value. It is not specific to
     this QOpenGLShaderProgram instance.
 
+    \note This function is only supported with OpenGL >= 4.0 and will not
+    return valid results with OpenGL ES 3.2.
+
     \sa setDefaultOuterTessellationLevels(), defaultInnerTessellationLevels()
 */
 QVector<float> QOpenGLShaderProgram::defaultOuterTessellationLevels() const
@@ -3620,6 +3603,9 @@ QVector<float> QOpenGLShaderProgram::defaultOuterTessellationLevels() const
     function when needed, as QOpenGLShaderProgram will not apply this for
     you. This is purely a convenience function.
 
+    \note This function is only available with OpenGL >= 4.0 and is not supported
+    with OpenGL ES 3.2.
+
     \sa defaultInnerTessellationLevels(), setDefaultOuterTessellationLevels()
 */
 void QOpenGLShaderProgram::setDefaultInnerTessellationLevels(const QVector<float> &levels)
@@ -3657,6 +3643,9 @@ void QOpenGLShaderProgram::setDefaultInnerTessellationLevels(const QVector<float
     \note This returns the global OpenGL state value. It is not specific to
     this QOpenGLShaderProgram instance.
 
+    \note This function is only supported with OpenGL >= 4.0 and will not
+    return valid results with OpenGL ES 3.2.
+
     \sa setDefaultInnerTessellationLevels(), defaultOuterTessellationLevels()
 */
 QVector<float> QOpenGLShaderProgram::defaultInnerTessellationLevels() const