CRenderTarget: Implement OpenGL support, including MSAA.

Still needs support for MSAA render targets though.

Author: CrossVR

src/Layers/xrRender/SH_RT.h

@@ -20,6 +20,8 @@ class		CRT		:	public xr_resource_named	{
 public:
 #ifdef USE_OGL
 	GLuint					pRT;
+	GLuint					pZRT;
+	GLenum					target;
 #else
 	ID3DTexture2D*			pSurface;
 	ID3DRenderTargetView*	pRT;

src/Layers/xrRender/light.h

@@ -51,11 +51,11 @@ class	light		:	public IRender_Light, public SpatialBase
 	ref_shader		s_point;
 	ref_shader		s_volumetric;
 
-#if (RENDER==R_R3) || (RENDER==R_R4)
+#if (RENDER==R_R3) || (RENDER==R_R4) || (RENDER==R_GL)
 	ref_shader		s_spot_msaa[8];
 	ref_shader		s_point_msaa[8];
 	ref_shader		s_volumetric_msaa[8];
-#endif	//	(RENDER==R_R3) || (RENDER==R_R4)
+#endif	//	(RENDER==R_R3) || (RENDER==R_R4) || (RENDER==R_GL)
 
 	u32				m_xform_frame;
 	Fmatrix			m_xform;

src/Layers/xrRender/r__dsgraph_render.cpp

@@ -542,7 +542,7 @@ void D3DXRenderBase::r_dsgraph_render_hud_ui()
 	const ref_rt	rt_null;
 	RCache.set_RT(0,	1);
 	RCache.set_RT(0,	2);
-#if	(RENDER==R_R3) || (RENDER==R_R4)
+#if	(RENDER==R_R3) || (RENDER==R_R4) || (RENDER==R_GL)
 	if( !RImplementation.o.dx10_msaa )
 	{
 		if (RImplementation.o.albedo_wo)	RImplementation.Target->u_setrt		(RImplementation.Target->rt_Accumulator,	rt_null,	rt_null,	HW.pBaseZB);

src/Layers/xrRenderGL/glR_Backend_Runtime.h

@@ -18,6 +18,7 @@ IC void CBackend::set_RT(GLuint RT, u32 ID)
 		PGO(Msg("PGO:setRT"));
 		stat.target_rt++;
 		pRT[ID] = RT;
+		// TODO: OGL: Implement support for multi-sampled render targets
 		CHK_GL(glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0 + ID, GL_TEXTURE_2D, RT, 0));
 	}
 }
@@ -29,6 +30,7 @@ IC void	CBackend::set_ZB(GLuint ZB)
 		PGO(Msg("PGO:setZB"));
 		stat.target_zb++;
 		pZB = ZB;
+		// TODO: OGL: Implement support for multi-sampled render targets
 		CHK_GL(glFramebufferTexture2D(GL_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT, GL_TEXTURE_2D, ZB, 0));
 	}
 }

src/Layers/xrRenderGL/glSH_RT.cpp

@@ -43,18 +43,25 @@ void CRT::create	(LPCSTR Name, u32 w, u32 h,	D3DFORMAT f, u32 SampleCount )
 
 	RImplementation.Resources->Evict();
 
+	target = (SampleCount > 1) ? GL_TEXTURE_2D_MULTISAMPLE : GL_TEXTURE_2D;
 	glGenTextures(1, &pRT);
-	CHK_GL(glBindTexture(GL_TEXTURE_2D, pRT));
-	CHK_GL(glTexStorage2D(GL_TEXTURE_2D, 1, glTextureUtils::ConvertTextureFormat(fmt), w, h));
+	CHK_GL(glBindTexture(target, pRT));
+	if (SampleCount > 1)
+		CHK_GL(glTexImage2DMultisample(GL_TEXTURE_2D_MULTISAMPLE, SampleCount, glTextureUtils::ConvertTextureFormat(fmt), w, h, GL_FALSE));
+	else
+		CHK_GL(glTexStorage2D(GL_TEXTURE_2D, 1, glTextureUtils::ConvertTextureFormat(fmt), w, h));
 
 	pTexture	= RImplementation.Resources->_CreateTexture	(Name);
-	pTexture->surface_set(GL_TEXTURE_2D, pRT);
+	pTexture->surface_set(target, pRT);
+
+	// OpenGL doesn't differentiate between color and depth targets
+	pZRT = pRT;
 }
 
 void CRT::destroy		()
 {
 	if (pTexture._get())	{
-		pTexture->surface_set(GL_TEXTURE_2D, 0);
+		pTexture->surface_set(target, 0);
 		pTexture = NULL;
 	}
 	CHK_GL(glDeleteTextures(1, &pRT));