Resurrect advanced bindTexture() features in QtOpenGL

During the Qt 4 -> 5 migration the setting of the extension flags
in QOpenGLFunctions/Extensions suffered a regression: flags like
GenerateMipmap were never set. This led to the unfortunate sitation
that features that were tied to these flags, like compressed texture
support or mipmap generation, got disabled.

This is now corrected by checking for the extensions like Qt 4 did.

Task-number: QTBUG-37588
Change-Id: I4a7beb1b435af11e05f5304aa04df2ec63b34c18
Reviewed-by: Gunnar Sletta <gunnar.sletta@jollamobile.com>

2 files changed, 82 insertions, 3 deletions

diff --git a/src/gui/opengl/qopenglfunctions.cpp b/src/gui/opengl/qopenglfunctions.cpp
index fe6eb4c098..d52b1a314f 100644
--- a/src/gui/opengl/qopenglfunctions.cpp
+++ b/src/gui/opengl/qopenglfunctions.cpp
@@ -359,10 +359,37 @@ static int qt_gl_resolve_extensions()
 {
     int extensions = 0;
     QOpenGLExtensionMatcher extensionMatcher;
+    QOpenGLContext *ctx = QOpenGLContext::currentContext();
+    QSurfaceFormat format = ctx->format();
+
     if (extensionMatcher.match("GL_EXT_bgra"))
         extensions |= QOpenGLExtensions::BGRATextureFormat;
-
-    if (QOpenGLContext::currentContext()->isES()) {
+    if (extensionMatcher.match("GL_ARB_texture_rectangle"))
+        extensions |= QOpenGLExtensions::TextureRectangle;
+    if (extensionMatcher.match("GL_SGIS_generate_mipmap"))
+        extensions |= QOpenGLExtensions::GenerateMipmap;
+    if (extensionMatcher.match("GL_ARB_texture_compression"))
+        extensions |= QOpenGLExtensions::TextureCompression;
+    if (extensionMatcher.match("GL_EXT_texture_compression_s3tc"))
+        extensions |= QOpenGLExtensions::DDSTextureCompression;
+    if (extensionMatcher.match("GL_OES_compressed_ETC1_RGB8_texture"))
+        extensions |= QOpenGLExtensions::ETC1TextureCompression;
+    if (extensionMatcher.match("GL_IMG_texture_compression_pvrtc"))
+        extensions |= QOpenGLExtensions::PVRTCTextureCompression;
+    if (extensionMatcher.match("GL_ARB_texture_mirrored_repeat"))
+        extensions |= QOpenGLExtensions::MirroredRepeat;
+    if (extensionMatcher.match("GL_EXT_stencil_two_side"))
+        extensions |= QOpenGLExtensions::StencilTwoSide;
+    if (extensionMatcher.match("GL_EXT_stencil_wrap"))
+        extensions |= QOpenGLExtensions::StencilWrap;
+    if (extensionMatcher.match("GL_NV_float_buffer"))
+        extensions |= QOpenGLExtensions::NVFloatBuffer;
+    if (extensionMatcher.match("GL_ARB_pixel_buffer_object"))
+        extensions |= QOpenGLExtensions::PixelBufferObject;
+
+    if (ctx->isES()) {
+        if (format.majorVersion() >= 2)
+            extensions |= QOpenGLExtensions::GenerateMipmap;
         if (extensionMatcher.match("GL_OES_mapbuffer"))
             extensions |= QOpenGLExtensions::MapBuffer;
         if (extensionMatcher.match("GL_OES_packed_depth_stencil"))
@@ -375,7 +402,6 @@ static int qt_gl_resolve_extensions()
         if (extensionMatcher.match("GL_IMG_texture_format_BGRA8888") || extensionMatcher.match("GL_EXT_texture_format_BGRA8888"))
             extensions |= QOpenGLExtensions::BGRATextureFormat;
     } else {
-        QSurfaceFormat format = QOpenGLContext::currentContext()->format();
         extensions |= QOpenGLExtensions::ElementIndexUint | QOpenGLExtensions::MapBuffer;
 
         // Recognize features by extension name.
@@ -394,6 +420,19 @@ static int qt_gl_resolve_extensions()
                 extensions |= QOpenGLExtensions::PackedDepthStencil;
         }
     }
+
+    if (format.renderableType() == QSurfaceFormat::OpenGL && format.version() >= qMakePair(3, 2))
+        extensions |= QOpenGLExtensions::GeometryShaders;
+
+#ifndef QT_OPENGL_ES
+    if (extensionMatcher.match("GL_EXT_framebuffer_sRGB")) {
+        GLboolean srgbCapableFramebuffers = false;
+        ctx->functions()->glGetBooleanv(GL_FRAMEBUFFER_SRGB_CAPABLE_EXT, &srgbCapableFramebuffers);
+        if (srgbCapableFramebuffers)
+            extensions |= QOpenGLExtensions::SRGBFrameBuffer;
+    }
+#endif
+
     return extensions;
 }
 
diff --git a/tests/auto/opengl/qgl/tst_qgl.cpp b/tests/auto/opengl/qgl/tst_qgl.cpp
index 718b5263bf..22f284e365 100644
--- a/tests/auto/opengl/qgl/tst_qgl.cpp
+++ b/tests/auto/opengl/qgl/tst_qgl.cpp
@@ -60,6 +60,7 @@
 #include <QtOpenGL/private/qgl_p.h>
 #include <QtGui/private/qimage_p.h>
 #include <QtGui/private/qimagepixmapcleanuphooks_p.h>
+#include <QtGui/private/qopenglextensions_p.h>
 #endif
 
 class tst_QGL : public QObject
@@ -99,6 +100,7 @@ private slots:
     void threadImages();
     void nullRectCrash();
     void graphicsViewClipping();
+    void extensions();
 };
 
 tst_QGL::tst_QGL()
@@ -2361,5 +2363,43 @@ void tst_QGL::nullRectCrash()
     fboPainter.end();
 }
 
+void tst_QGL::extensions()
+{
+    QGLWidget glw;
+    glw.makeCurrent();
+
+    QOpenGLContext *ctx = QOpenGLContext::currentContext();
+    QVERIFY(ctx);
+    QOpenGLFunctions *funcs = ctx->functions();
+    QVERIFY(funcs);
+    QSurfaceFormat format = ctx->format();
+
+#ifdef QT_BUILD_INTERNAL
+    QOpenGLExtensions *exts = static_cast<QOpenGLExtensions *>(funcs);
+    QOpenGLExtensions::OpenGLExtensions allExts = exts->openGLExtensions();
+    // Mipmapping is always available in GL2/GLES2+. Verify this.
+    if (format.majorVersion() >= 2)
+        QVERIFY(allExts.testFlag(QOpenGLExtensions::GenerateMipmap));
+#endif
+
+    // Now look for some features should always be available in a given version.
+    QOpenGLFunctions::OpenGLFeatures allFeatures = funcs->openGLFeatures();
+    QVERIFY(allFeatures.testFlag(QOpenGLFunctions::Multitexture));
+    if (format.majorVersion() >= 2) {
+        QVERIFY(allFeatures.testFlag(QOpenGLFunctions::Shaders));
+        QVERIFY(allFeatures.testFlag(QOpenGLFunctions::Buffers));
+        QVERIFY(allFeatures.testFlag(QOpenGLFunctions::Multisample));
+        QVERIFY(!ctx->isES() || allFeatures.testFlag(QOpenGLFunctions::Framebuffers));
+        QVERIFY(allFeatures.testFlag(QOpenGLFunctions::NPOTTextures)
+                && allFeatures.testFlag(QOpenGLFunctions::NPOTTextureRepeat));
+        if (ctx->isES()) {
+            QVERIFY(!allFeatures.testFlag(QOpenGLFunctions::FixedFunctionPipeline));
+            QVERIFY(allFeatures.testFlag(QOpenGLFunctions::Framebuffers));
+        }
+    }
+    if (format.majorVersion() >= 3)
+        QVERIFY(allFeatures.testFlag(QOpenGLFunctions::Framebuffers));
+}
+
 QTEST_MAIN(tst_QGL)
 #include "tst_qgl.moc"