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macosopenglsdltextures

SDL OpenGL SDL_image Mac: Display Output (shifted colors)

We load textures through SDL_image, then we load them into OpenGL through textimage2d:

glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, texture->w, texture->h,
0, GL_BGRA_EXT, GL_UNSIGNED_BYTE, (GLuint**)texture->pixels );

On my windows machine, that runs fine, but on my friends Mac machine the colors seem to be shifted around. He got a strong blueish texture on his display. Of course, that has to deal with the internalFormat (here GL_BGRA_EXT). We tried all we found and running (compiling correctly) but none gives a correct output for mac. Any ideas how to get an idea about how mac computes the pixels array provided by SDL_image?

Solution

  • Okay thanks to your links, some investigation and lost brain cells, we came to the result that we can detect the order of pixel data trough the defined masks in the sdl surface (surface->format->Rmask) to decide if we use GL_UNSIGNED_INT_8_8_8_8 or GL_UNSIGNED_INT_8_8_8_8_REV.