gl_rendertarget_phase_flip: Render the scene up-side down and flip it as a last step.

Allows for easier compatibility with DirectX.

Author: CrossVR

src/Layers/xrRender/HW.h

@@ -59,6 +59,7 @@ class  CHW
 public:
 	CHW*					pDevice;
 	CHW*					pContext;
+	CHW*					m_pSwapChain;
 	GLuint					pBaseRT;
 	GLuint					pBaseZB;
 	GLuint					pPP;
@@ -137,6 +138,7 @@ class  CHW
 	// TODO: OGL: Implement this into a compatibility layer?
 	void ClearRenderTargetView(GLuint pRenderTargetView, const FLOAT ColorRGBA[4]);
 	void ClearDepthStencilView(GLuint pDepthStencilView, UINT ClearFlags, FLOAT Depth, UINT8 Stencil);
+	HRESULT Present(UINT SyncInterval, UINT Flags);
 #endif // USE_OGL
 
 

src/Layers/xrRender/r__dsgraph_build.cpp

@@ -1077,9 +1077,7 @@ void D3DXRenderBase::End()
 	RCache.OnFrameEnd();
 	Memory.dbg_check();
 	DoAsyncScreenshot();
-#if defined(USE_OGL)
-	SwapBuffers(HW.m_hDC);
-#elif defined(USE_DX10) || defined(USE_DX11)
+#if defined(USE_DX10) || defined(USE_DX11) || defined(USE_OGL)
 	HW.m_pSwapChain->Present(0, 0);
 #else
 	CHK_DX(HW.pDevice->EndScene());

src/Layers/xrRenderGL/glHW.cpp

@@ -38,6 +38,7 @@ CHW::CHW() :
 	m_hRC(NULL),
 	pDevice(this),
 	pContext(this),
+	m_pSwapChain(this),
 	m_move_window(true),
 	pBaseRT(0),
 	pBaseZB(0),
@@ -132,7 +133,7 @@ void CHW::CreateDevice( HWND hWnd, bool move_window )
 	// Clip control ensures compatibility with D3D device coordinates.
 	// TODO: OGL: Also use GL_UPPER_LEFT to match D3D.
 	// TODO: OGL: Fix these differences in the blenders/shaders.
-	CHK_GL(glClipControl(GL_LOWER_LEFT, GL_ZERO_TO_ONE));
+	CHK_GL(glClipControl(GL_UPPER_LEFT, GL_ZERO_TO_ONE));
 
 	//	Create render target and depth-stencil views here
 	UpdateViews();
@@ -346,11 +347,12 @@ void CHW::UpdateViews()
 	// Create the clear framebuffer
 	glGenFramebuffers(1, &pCFB);
 
-	// Create a render target view
-	// We reserve a texture name to represent GL_BACK
+	// Create a color render target
 	glGenTextures(1, &HW.pBaseRT);
+	CHK_GL(glBindTexture(GL_TEXTURE_2D, HW.pBaseRT));
+	CHK_GL(glTexStorage2D(GL_TEXTURE_2D, 1, GL_RGBA8, psCurrentVidMode[0], psCurrentVidMode[1]));
 
-	// Create Depth/stencil buffer
+	// Create depth/stencil buffer
 	glGenTextures(1, &HW.pBaseZB);
 	CHK_GL(glBindTexture(GL_TEXTURE_2D, HW.pBaseZB));
 	CHK_GL(glTexStorage2D(GL_TEXTURE_2D, 1, GL_DEPTH24_STENCIL8, psCurrentVidMode[0], psCurrentVidMode[1]));
@@ -372,6 +374,8 @@ void CHW::ClearRenderTargetView(GLuint pRenderTargetView, const FLOAT ColorRGBA[
 	glClearColor(ColorRGBA[0], ColorRGBA[1], ColorRGBA[2], ColorRGBA[3]);
 	CHK_GL(glClear(GL_COLOR_BUFFER_BIT));
 	glPopAttrib();
+
+	RCache.set_FB(pFB);
 }
 
 void CHW::ClearDepthStencilView(GLuint pDepthStencilView, UINT ClearFlags, FLOAT Depth, UINT8 Stencil)
@@ -403,5 +407,13 @@ void CHW::ClearDepthStencilView(GLuint pDepthStencilView, UINT ClearFlags, FLOAT
 	}
 	CHK_GL(glClear((ClearBufferMask)mask));
 	glPopAttrib();
+
+	RCache.set_FB(pFB);
+}
+
+HRESULT CHW::Present(UINT SyncInterval, UINT Flags)
+{
+	RImplementation.Target->phase_flip();
+	return SwapBuffers(m_hDC) ? S_OK : E_FAIL;
 }
 #endif

src/Layers/xrRenderPC_GL/gl_rendertarget.cpp

@@ -21,7 +21,6 @@ void	CRenderTarget::u_setrt(const ref_rt& _1, const ref_rt& _2, const ref_rt& _3
 	dwHeight = _1->dwHeight;
 	GLuint cnt = 0;
 	GLenum buffers[3] = { GL_NONE };
-	RCache.set_FB(HW.pFB);
 	if (_1)
 	{
 		buffers[cnt++] = GL_COLOR_ATTACHMENT0;
@@ -51,7 +50,6 @@ void	CRenderTarget::u_setrt(const ref_rt& _1, const ref_rt& _2, GLuint zb)
 	dwHeight = _1->dwHeight;
 	GLuint cnt = 0;
 	GLenum buffers[2] = { GL_NONE };
-	RCache.set_FB(HW.pFB);
 	if (_1)
 	{
 		buffers[cnt++] = GL_COLOR_ATTACHMENT0;
@@ -75,13 +73,6 @@ void	CRenderTarget::u_setrt(u32 W, u32 H, GLuint _1, GLuint _2, GLuint _3, GLuin
 	dwHeight = H;
 	GLuint cnt = 0;
 	GLenum buffers[3] = { GL_NONE };
-	if (_1 == HW.pBaseRT)
-	{
-		RCache.set_FB();
-		return;
-	}
-
-	RCache.set_FB(HW.pFB);
 	if (_1)
 	{
 		buffers[cnt++] = GL_COLOR_ATTACHMENT0;
@@ -844,6 +835,12 @@ CRenderTarget::CRenderTarget		()
 	s_menu.create						("distort");
 	g_menu.create						(FVF::F_TL,RCache.Vertex.Buffer(),RCache.QuadIB);
 
+	// Flip
+	t_base								= RImplementation.Resources->_CreateTexture	(r2_base);
+	t_base->surface_set					(GL_TEXTURE_2D, HW.pBaseRT);
+	s_flip.create						("effects\\screen_set",		r2_base);
+	g_flip.create						(FVF::F_TL, RCache.Vertex.Buffer(), RCache.QuadIB);
+
 	// 
 	dwWidth		= Device.dwWidth;
 	dwHeight	= Device.dwHeight;

src/Layers/xrRenderPC_GL/gl_rendertarget.h

@@ -106,6 +106,8 @@ class CRenderTarget		: public IRender_Target
 	ref_texture					t_noise				[TEX_jitter_count];
 	GLuint			t_noise_surf_mipped;
 	ref_texture					t_noise_mipped;
+
+	ref_texture					t_base;
 private:
 	// OCCq
 
@@ -192,6 +194,8 @@ class CRenderTarget		: public IRender_Target
 	ref_geom					g_postprocess;
 	ref_shader				s_menu;
 	ref_geom					g_menu;
+	ref_shader					s_flip;
+	ref_geom					g_flip;
 private:
 	float						im_noise_time;
 	u32							im_noise_shift_w;
@@ -290,6 +294,7 @@ class CRenderTarget		: public IRender_Target
 	void						phase_combine			();
 	void						phase_combine_volumetric();
 	void						phase_pp				();
+	void						phase_flip				();
 
 	virtual void				set_blur				(float	f)		{ param_blur=f;						}
 	virtual void				set_gray				(float	f)		{ param_gray=f;						}

src/Layers/xrRenderPC_GL/gl_rendertarget_phase_flip.cpp

@@ -0,0 +1,36 @@
+#include "stdafx.h"
+
+void	CRenderTarget::phase_flip	()
+{
+	PIX_EVENT(phase_flip);
+
+	// Switch to backbuffer
+	RCache.set_FB();
+
+	// common calc for quad-rendering
+	u32		Offset;
+	u32		C					= color_rgba	(255,255,255,255);
+	float	_w					= float			(Device.dwWidth);
+	float	_h					= float			(Device.dwHeight);
+	Fvector2					p0,p1;
+	p0.set						(.5f/_w, .5f/_h);
+	p1.set						((_w+.5f)/_w, (_h+.5f)/_h );
+	float	d_Z	= EPS_S, d_W = 1.f;
+
+	// Fill vertex buffer
+	FVF::TL* pv					= (FVF::TL*)	RCache.Vertex.Lock	(4,g_flip->vb_stride,Offset);
+	pv->set						(EPS,			float(_h+EPS),	d_Z,	d_W, C, p0.x, p0.y);	pv++;
+	pv->set						(EPS,			EPS,			d_Z,	d_W, C, p0.x, p1.y);	pv++;
+	pv->set						(float(_w+EPS),	float(_h+EPS),	d_Z,	d_W, C, p1.x, p0.y);	pv++;
+	pv->set						(float(_w+EPS),	EPS,			d_Z,	d_W, C, p1.x, p1.y);	pv++;
+	RCache.Vertex.Unlock		(4,g_flip->vb_stride);
+	
+	// Draw
+	RCache.set_Element			(s_flip->E[0]	);
+	RCache.set_Geometry			(g_flip			);
+
+	RCache.Render				(D3DPT_TRIANGLELIST,Offset,0,4,0,2);
+
+	// Switch to framebuffer
+	RCache.set_FB(HW.pFB);
+}

src/Layers/xrRenderPC_GL/r2_types.h

@@ -49,6 +49,8 @@
 #define		r2_jitter_mipped	"$user$jitter_mipped"			// --- dither
 #define		r2_sunmask			"sunmask"
 
+#define		r2_base				"$user$base"
+
 #define		JITTER(a) r2_jitter #a
 
 const		float				SMAP_near_plane		= .1f	;

src/Layers/xrRenderPC_GL/xrRender_GL.vcxproj

@@ -268,6 +268,7 @@
     <ClCompile Include="gl_rendertarget_phase_accumulator.cpp" />
     <ClCompile Include="gl_rendertarget_phase_bloom.cpp" />
     <ClCompile Include="gl_rendertarget_phase_combine.cpp" />
+    <ClCompile Include="gl_rendertarget_phase_flip.cpp" />
     <ClCompile Include="gl_rendertarget_phase_luminance.cpp" />
     <ClCompile Include="gl_rendertarget_phase_occq.cpp" />
     <ClCompile Include="gl_rendertarget_phase_PP.cpp" />

src/Layers/xrRenderPC_GL/xrRender_GL.vcxproj.filters

@@ -681,6 +681,9 @@
     <ClCompile Include="..\xrRenderGL\MSAA\glMSAABlender.cpp">
       <Filter>Interface implementations\MSAARender</Filter>
     </ClCompile>
+    <ClCompile Include="gl_rendertarget_phase_flip.cpp">
+      <Filter>Core_Target</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="stdafx.h">