Problem in running cube example: 'glActiveTexture' was not declared in this scope'

[Karunesh]

I am trying to run the cube example for Symbian^3 with OpenGL ES 2,0 but it does not compile. There are two errors, one saying that glActiveTexture is not declared and the other saying the same for GL_TEXTURE0.

I chanced upon a forum post "here ":https://qt-project.org/forums/viewthread/6884, and it turns out that we have to include the QGLFunctions module, but still one error remains: 'glActiveTexture' was not declared in this scope', i.e. the glActiveTexture primitive is not being identified by opengl.

The glActiveTexture primitive only sets the texture mode to GL_TEXTURE0, which is default. So removing the line (the first line in function 'initTextures' in mainwidget.cpp) should be fine, but the application crashes on doing so.

Any help is appreciated. Thanks.

[Blizzard]

Use "glext.h":www.opengl.org/registry/api/glext.h and make sure you have the following 2 lines in your code:
@#define GL_GLEXT_PROTOTYPES
#include <GL/gl.h>@

[Blizzard]

If it still doesn't work, try using:
@#define GL_GLEXT_LEGACY@

in place of

@#define GL_GLEXT_PROTOTYPES@

[Karunesh]

Hi

I inserted the two lines (with both GL_GLEXT_PROTOTYPES and GL_GLEXT_LEGACY i.e. first one then the other). The code is compiling fine but its crashing with an assertion in the qglfunctions.h file.

Exact debugger output:
bq. Initializing shaders...
Initializing geometries...
ASSERT: "QGLFunctions::isInitialized(d_ptr)" in file ........\Desktop\Qt\4.8.0\mingw\include/QtOpenGL/qglfunctions.h, line 719
Invalid parameter passed to C runtime function.
Invalid parameter passed to C runtime function.

I also tried directly including glext.h, but the same assertion persists.