The code in OGC_UpdateTexture was not calling DC_FlushRange() after modifying the texel data. Since the code obtained when adding this call is very similar to the implementation in OGC_UnlockTexture(), move the texture updating code into a common function.
The code in OGC_UpdateTexture was not calling DC_FlushRange() after modifying the texel data. Since the code obtained when adding this call is very similar to the implementation in OGC_UnlockTexture(), move the texture updating code into a common function.