Method ClearFramebuffer

desmume/src/render3D.cpp:132–175

}

Render3DError Render3D::ClearFramebuffer(const GFX3D_State *renderState)
{
	Render3DError error = RENDER3DERROR_NOERR;
	
	struct GFX3D_ClearColor
	{
		u8 r;
		u8 g;
		u8 b;
		u8 a;
	} clearColor;
	
	clearColor.r = renderState->clearColor & 0x1F;
	clearColor.g = (renderState->clearColor >> 5) & 0x1F;
	clearColor.b = (renderState->clearColor >> 10) & 0x1F;
	clearColor.a = (renderState->clearColor >> 16) & 0x1F;
	
	const u8 clearStencil = (renderState->clearColor >> 24) & 0x3F;
	
	if (renderState->enableClearImage)
	{
		const u16 *__restrict clearColorBuffer = (u16 *__restrict)MMU.texInfo.textureSlotAddr[2];
		const u16 *__restrict clearDepthBuffer = (u16 *__restrict)MMU.texInfo.textureSlotAddr[3];
		const u16 scrollBits = T1ReadWord(MMU.ARM9_REG, 0x356); //CLRIMAGE_OFFSET
		const u8 xScroll = scrollBits & 0xFF;
		const u8 yScroll = (scrollBits >> 8) & 0xFF;
		
		error = this->UpdateClearImage(clearColorBuffer, clearDepthBuffer, clearStencil, xScroll, yScroll);
		if (error == RENDER3DERROR_NOERR)
		{
			error = this->ClearUsingImage();
		}
		else
		{
			error = this->ClearUsingValues(clearColor.r, clearColor.g, clearColor.b, clearColor.a, renderState->clearDepth, clearStencil);
		}
	}
	else
	{
		error = this->ClearUsingValues(clearColor.r, clearColor.g, clearColor.b, clearColor.a, renderState->clearDepth, clearStencil);
	}
	
	return error;
}

Render3DError Render3D::ClearUsingImage() const
{