Added blend equation support.

include/bgfx.h

@@ -40,7 +40,14 @@
 #define BGFX_STATE_BLEND_FACTOR          UINT64_C(0x000000000000c000)
 #define BGFX_STATE_BLEND_INV_FACTOR      UINT64_C(0x000000000000d000)
 #define BGFX_STATE_BLEND_SHIFT           12
-#define BGFX_STATE_BLEND_MASK            UINT64_C(0x000000000ffff000)
+#define BGFX_STATE_BLEND_MASK            UINT64_C(0x00000000000ff000)
+
+#define BGFX_STATE_BLEND_EQUATION_SUB    UINT64_C(0x0000000000100000)
+#define BGFX_STATE_BLEND_EQUATION_REVSUB UINT64_C(0x0000000000200000)
+#define BGFX_STATE_BLEND_EQUATION_MIN    UINT64_C(0x0000000000300000)
+#define BGFX_STATE_BLEND_EQUATION_MAX    UINT64_C(0x0000000000400000)
+#define BGFX_STATE_BLEND_EQUATION_SHIFT  20
+#define BGFX_STATE_BLEND_EQUATION_MASK   UINT64_C(0x0000000000700000)
 
 #define BGFX_STATE_CULL_CW               UINT64_C(0x0000000010000000)
 #define BGFX_STATE_CULL_CCW              UINT64_C(0x0000000020000000)
@@ -80,6 +87,14 @@
 #define BGFX_STATE_POINT_SIZE(_size) ( (uint64_t(_size)<<BGFX_STATE_POINT_SIZE_SHIFT)&BGFX_STATE_POINT_SIZE_MASK)
 #define BGFX_STATE_BLEND_FUNC(_src, _dst) ( uint64_t(_src)|( uint64_t(_dst)<<4) )
 
+#define BGFX_STATE_BLEND_ADD         (BGFX_STATE_BLEND_FUNC(BGFX_STATE_BLEND_ONE,       BGFX_STATE_BLEND_ONE          ) )
+#define BGFX_STATE_BLEND_ALPHA       (BGFX_STATE_BLEND_FUNC(BGFX_STATE_BLEND_SRC_ALPHA, BGFX_STATE_BLEND_INV_SRC_COLOR) )
+#define BGFX_STATE_BLEND_DARKEN      (BGFX_STATE_BLEND_FUNC(BGFX_STATE_BLEND_ONE,       BGFX_STATE_BLEND_ONE          ) | BGFX_STATE_BLEND_EQUATION_MIN)
+#define BGFX_STATE_BLEND_LIGHTEN     (BGFX_STATE_BLEND_FUNC(BGFX_STATE_BLEND_ONE,       BGFX_STATE_BLEND_ONE          ) | BGFX_STATE_BLEND_EQUATION_MAX)
+#define BGFX_STATE_BLEND_MULTIPLY    (BGFX_STATE_BLEND_FUNC(BGFX_STATE_BLEND_DST_COLOR, BGFX_STATE_BLEND_ZERO         ) )
+#define BGFX_STATE_BLEND_SCREEN      (BGFX_STATE_BLEND_FUNC(BGFX_STATE_BLEND_ONE,       BGFX_STATE_BLEND_INV_SRC_COLOR) )
+#define BGFX_STATE_BLEND_LINEAR_BURN (BGFX_STATE_BLEND_FUNC(BGFX_STATE_BLEND_DST_COLOR, BGFX_STATE_BLEND_INV_DST_COLOR) | BGFX_STATE_BLEND_EQUATION_SUB)
+
 ///
 #define BGFX_STENCIL_FUNC_REF_SHIFT      0
 #define BGFX_STENCIL_FUNC_REF_MASK       UINT32_C(0x000000ff)
@@ -788,7 +803,8 @@ namespace bgfx
 	///   BGFX_STATE_ALPHA_WRITE - Enable alpha write.
 	///   BGFX_STATE_DEPTH_WRITE - Enable depth write.
 	///   BGFX_STATE_DEPTH_TEST_* - Depth test function.
-	///   BGFX_STATE_BLEND_* - See NOTE: BGFX_STATE_BLEND_FUNC.
+	///   BGFX_STATE_BLEND_* - See NOTE 1: BGFX_STATE_BLEND_FUNC.
+	///   BGFX_STATE_BLEND_EQUATION_* - See NOTE 2.
 	///   BGFX_STATE_CULL_* - Backface culling mode.
 	///   BGFX_STATE_RGB_WRITE - Enable RGB write.
 	///   BGFX_STATE_SRGBWRITE - Enable sRGB write.
@@ -799,8 +815,10 @@ namespace bgfx
 	///   BGFX_STATE_BLEND_INV_FACTOR blend modes.
 	///
 	/// NOTE:
-	///   Use BGFX_STATE_ALPHA_REF, BGFX_STATE_POINT_SIZE and
-	///   BGFX_STATE_BLEND_FUNC macros to setup more complex states.
+	///   1. Use BGFX_STATE_ALPHA_REF, BGFX_STATE_POINT_SIZE and
+	///      BGFX_STATE_BLEND_FUNC macros to setup more complex states.
+	///   2. BGFX_STATE_BLEND_EQUATION_ADD is set when no other blend
+	///      equation is specified.
 	///
 	void setState(uint64_t _state, uint32_t _rgba = UINT32_MAX);
 

src/renderer_d3d11.cpp

@@ -57,6 +57,15 @@ namespace bgfx
 		{ D3D11_BLEND_INV_BLEND_FACTOR, D3D11_BLEND_INV_BLEND_FACTOR },
 	};
 
+	static const D3D11_BLEND_OP s_blendEquation[] =
+	{
+		D3D11_BLEND_OP_ADD,
+		D3D11_BLEND_OP_SUBTRACT,
+		D3D11_BLEND_OP_REV_SUBTRACT,
+		D3D11_BLEND_OP_MIN,
+		D3D11_BLEND_OP_MAX,
+	};
+
 	static const D3D11_COMPARISON_FUNC s_depthFunc[] =
 	{
 		D3D11_COMPARISON_LESS, // ignored
@@ -795,7 +804,7 @@ namespace bgfx
 
 		void setBlendState(uint64_t _state, uint32_t _rgba = UINT32_MAX)
 		{
-			_state &= BGFX_STATE_BLEND_MASK|BGFX_STATE_ALPHA_WRITE|BGFX_STATE_RGB_WRITE;
+			_state &= BGFX_STATE_BLEND_MASK|BGFX_STATE_BLEND_EQUATION_MASK|BGFX_STATE_ALPHA_WRITE|BGFX_STATE_RGB_WRITE;
 
 			ID3D11BlendState* bs = m_blendStateCache.find(_state);
 			if (NULL == bs)
@@ -806,6 +815,7 @@ namespace bgfx
 				drt.BlendEnable = !!(BGFX_STATE_BLEND_MASK & _state);
 
 				uint32_t blend = (_state&BGFX_STATE_BLEND_MASK)>>BGFX_STATE_BLEND_SHIFT;
+				uint32_t equation = (_state&BGFX_STATE_BLEND_EQUATION_MASK)>>BGFX_STATE_BLEND_EQUATION_SHIFT;
 				uint32_t src = blend&0xf;
 				uint32_t dst = (blend>>4)&0xf;
 				uint32_t writeMask = (_state&BGFX_STATE_ALPHA_WRITE) ? D3D11_COLOR_WRITE_ENABLE_ALPHA : 0;
@@ -813,11 +823,11 @@ namespace bgfx
 
 				drt.SrcBlend = s_blendFactor[src][0];
 				drt.DestBlend = s_blendFactor[dst][0];
-				drt.BlendOp = D3D11_BLEND_OP_ADD;
+				drt.BlendOp = s_blendEquation[equation];
 
 				drt.SrcBlendAlpha = s_blendFactor[src][1];
 				drt.DestBlendAlpha = s_blendFactor[dst][1];
-				drt.BlendOpAlpha = D3D11_BLEND_OP_ADD;
+				drt.BlendOpAlpha = s_blendEquation[equation];
 
 				drt.RenderTargetWriteMask = writeMask;
 
@@ -2385,11 +2395,20 @@ namespace bgfx
 					s_renderCtx.setDepthStencilState(newFlags, newStencil);
 				}
 
-				if ( (BGFX_STATE_CULL_MASK|BGFX_STATE_ALPHA_MASK|BGFX_STATE_RGB_WRITE
-					 |BGFX_STATE_BLEND_MASK|BGFX_STATE_ALPHA_REF_MASK|BGFX_STATE_PT_MASK
-					 |BGFX_STATE_POINT_SIZE_MASK|BGFX_STATE_SRGBWRITE|BGFX_STATE_MSAA) & changedFlags)
+				if ( (0
+					 | BGFX_STATE_CULL_MASK
+					 | BGFX_STATE_ALPHA_MASK
+					 | BGFX_STATE_RGB_WRITE
+					 | BGFX_STATE_BLEND_MASK
+					 | BGFX_STATE_BLEND_EQUATION_MASK
+					 | BGFX_STATE_ALPHA_REF_MASK
+					 | BGFX_STATE_PT_MASK
+					 | BGFX_STATE_POINT_SIZE_MASK
+					 | BGFX_STATE_SRGBWRITE
+					 | BGFX_STATE_MSAA
+					 ) & changedFlags)
 				{
-					if ( (BGFX_STATE_BLEND_MASK|BGFX_STATE_ALPHA_WRITE|BGFX_STATE_RGB_WRITE) & changedFlags)
+					if ( (BGFX_STATE_BLEND_MASK|BGFX_STATE_BLEND_EQUATION_MASK|BGFX_STATE_ALPHA_WRITE|BGFX_STATE_RGB_WRITE) & changedFlags)
 					{
 						s_renderCtx.setBlendState(newFlags, state.m_rgba);
 					}

src/renderer_d3d9.cpp

@@ -62,6 +62,15 @@ namespace bgfx
 		{ D3DBLEND_INVBLENDFACTOR, D3DBLEND_INVBLENDFACTOR, true  },
 	};
 
+	static const D3DBLENDOP s_blendEquation[] =
+	{
+		D3DBLENDOP_ADD,
+		D3DBLENDOP_SUBTRACT,
+		D3DBLENDOP_REVSUBTRACT,
+		D3DBLENDOP_MIN,
+		D3DBLENDOP_MAX,
+	};
+
 	static const D3DCMPFUNC s_depthFunc[] =
 	{
 		(D3DCMPFUNC)0, // ignored
@@ -2361,10 +2370,20 @@ namespace bgfx
 					}
 				}
 
-				if ( (BGFX_STATE_CULL_MASK|BGFX_STATE_DEPTH_WRITE|BGFX_STATE_DEPTH_TEST_MASK
-					 |BGFX_STATE_ALPHA_MASK|BGFX_STATE_RGB_WRITE|BGFX_STATE_BLEND_MASK
-					 |BGFX_STATE_ALPHA_REF_MASK|BGFX_STATE_PT_MASK|BGFX_STATE_POINT_SIZE_MASK
-					 |BGFX_STATE_SRGBWRITE|BGFX_STATE_MSAA) & changedFlags)
+				if ( (0
+					 | BGFX_STATE_CULL_MASK
+					 | BGFX_STATE_DEPTH_WRITE
+					 | BGFX_STATE_DEPTH_TEST_MASK
+					 | BGFX_STATE_ALPHA_MASK
+					 | BGFX_STATE_RGB_WRITE
+					 | BGFX_STATE_BLEND_MASK
+					 | BGFX_STATE_BLEND_EQUATION_MASK
+					 | BGFX_STATE_ALPHA_REF_MASK
+					 | BGFX_STATE_PT_MASK
+					 | BGFX_STATE_POINT_SIZE_MASK
+					 | BGFX_STATE_SRGBWRITE
+					 | BGFX_STATE_MSAA
+					 ) & changedFlags)
 				{
 					if (BGFX_STATE_CULL_MASK & changedFlags)
 					{
@@ -2418,7 +2437,7 @@ namespace bgfx
 						DX_CHECK(device->SetRenderState(D3DRS_COLORWRITEENABLE, writeEnable) );
 					}
 
-					if (BGFX_STATE_BLEND_MASK & changedFlags)
+					if ( (BGFX_STATE_BLEND_MASK|BGFX_STATE_BLEND_EQUATION_MASK) & changedFlags)
 					{
 						bool alphaBlendEnabled = !!(BGFX_STATE_BLEND_MASK & newFlags);
 						DX_CHECK(device->SetRenderState(D3DRS_ALPHABLENDENABLE, alphaBlendEnabled) );
@@ -2427,11 +2446,13 @@ namespace bgfx
 						if (alphaBlendEnabled)
 						{
 							uint32_t blend = (newFlags&BGFX_STATE_BLEND_MASK)>>BGFX_STATE_BLEND_SHIFT;
+							uint32_t equation = (newFlags&BGFX_STATE_BLEND_EQUATION_MASK)>>BGFX_STATE_BLEND_EQUATION_SHIFT;
 							uint32_t src = blend&0xf;
 							uint32_t dst = (blend>>4)&0xf;
 
  							DX_CHECK(device->SetRenderState(D3DRS_SRCBLEND, s_blendFactor[src].m_src) );
 							DX_CHECK(device->SetRenderState(D3DRS_DESTBLEND, s_blendFactor[dst].m_dst) );
+							DX_CHECK(device->SetRenderState(D3DRS_BLENDOP, s_blendEquation[equation]) );
 //							DX_CHECK(device->SetRenderState(D3DRS_SRCBLENDALPHA, D3DBLEND_SRCALPHA) );
 //							DX_CHECK(device->SetRenderState(D3DRS_DESTBLENDALPHA, D3DBLEND_INVSRCALPHA) );
 

src/renderer_gl.cpp

@@ -62,6 +62,8 @@ namespace bgfx
 			OES_rgb8_rgba8,
 			EXT_texture_storage,
 			EXT_blend_color,
+			EXT_blend_subtract,
+			EXT_blend_minmax,
 			ARB_debug_output,
 
 			Count
@@ -118,6 +120,8 @@ namespace bgfx
 		{ "GL_OES_rgb8_rgba8",                    false,                             true  },
 		{ "GL_EXT_texture_storage",               false,                             true  },
 		{ "GL_EXT_blend_color",                   BGFX_CONFIG_RENDERER_OPENGL >= 31, true  },
+		{ "GL_EXT_blend_subtract",                BGFX_CONFIG_RENDERER_OPENGL >= 31, true  }, 
+		{ "GL_EXT_blend_minmax",                  BGFX_CONFIG_RENDERER_OPENGL >= 31, true  },
 		{ "GL_ARB_debug_output",                  BGFX_CONFIG_RENDERER_OPENGL >= 43, true  },
 	};
 
@@ -709,6 +713,15 @@ namespace bgfx
 		{ GL_ONE_MINUS_CONSTANT_COLOR, GL_ONE_MINUS_CONSTANT_COLOR, true  },
 	};
 
+	static const GLenum s_blendEquation[] =
+	{
+		GL_FUNC_ADD,
+		GL_FUNC_SUBTRACT,
+		GL_FUNC_REVERSE_SUBTRACT,
+		GL_MIN,
+		GL_MAX,
+	};
+
 	static const GLenum s_depthFunc[] =
 	{
 		0, // ignored
@@ -2597,7 +2610,7 @@ namespace bgfx
 
 	void Context::rendererSetMarker(const char* _marker, uint32_t /*_size*/)
 	{
-		GREMEDY_SETMARKER(_marker);
+		GREMEDY_SETMARKER(_marker);		
 	}
 
 	void Context::rendererSubmit()
@@ -2762,10 +2775,19 @@ namespace bgfx
 					}
 				}
 
-				if ( (BGFX_STATE_CULL_MASK|BGFX_STATE_DEPTH_WRITE|BGFX_STATE_DEPTH_TEST_MASK
-				     |BGFX_STATE_ALPHA_MASK|BGFX_STATE_RGB_WRITE|BGFX_STATE_BLEND_MASK
-					 |BGFX_STATE_ALPHA_REF_MASK|BGFX_STATE_PT_MASK|BGFX_STATE_POINT_SIZE_MASK
-					 |BGFX_STATE_MSAA) & changedFlags)
+				if ( (0
+					 | BGFX_STATE_CULL_MASK
+					 | BGFX_STATE_DEPTH_WRITE
+					 | BGFX_STATE_DEPTH_TEST_MASK
+					 | BGFX_STATE_ALPHA_MASK
+					 | BGFX_STATE_RGB_WRITE
+					 | BGFX_STATE_BLEND_MASK
+					 | BGFX_STATE_BLEND_EQUATION_MASK
+					 | BGFX_STATE_ALPHA_REF_MASK
+					 | BGFX_STATE_PT_MASK
+					 | BGFX_STATE_POINT_SIZE_MASK
+					 | BGFX_STATE_MSAA
+					 ) & changedFlags)
 				{
 					if (BGFX_STATE_CULL_MASK & changedFlags)
 					{
@@ -2838,15 +2860,17 @@ namespace bgfx
 						GL_CHECK(glColorMask(rgb, rgb, rgb, alpha) );
 					}
 
-					if (BGFX_STATE_BLEND_MASK & changedFlags)
+					if ( (BGFX_STATE_BLEND_MASK|BGFX_STATE_BLEND_EQUATION_MASK) & changedFlags)
 					{
 						if (BGFX_STATE_BLEND_MASK & newFlags)
 						{
 							uint32_t blend = (newFlags&BGFX_STATE_BLEND_MASK)>>BGFX_STATE_BLEND_SHIFT;
+							uint32_t equation = (newFlags&BGFX_STATE_BLEND_EQUATION_MASK)>>BGFX_STATE_BLEND_EQUATION_SHIFT;
 							uint32_t src = blend&0xf;
 							uint32_t dst = (blend>>4)&0xf;
 							GL_CHECK(glEnable(GL_BLEND) );
 							GL_CHECK(glBlendFunc(s_blendFactor[src].m_src, s_blendFactor[dst].m_dst) );
+							GL_CHECK(glBlendEquation(s_blendEquation[equation]) );
 
 							if ( (s_blendFactor[src].m_factor || s_blendFactor[dst].m_factor)
 							&&  blendFactor != state.m_rgba)

src/renderer_gl.h

@@ -80,6 +80,8 @@
 #		define GL_R32F GL_R32F_EXT
 #		define GL_UNSIGNED_INT_2_10_10_10_REV GL_UNSIGNED_INT_2_10_10_10_REV_EXT
 #		define GL_SAMPLER_3D GL_SAMPLER_3D_OES
+#		define GL_MIN GL_MIN_EXT
+#		define GL_MAX GL_MAX_EXT
 #	elif BGFX_CONFIG_RENDERER_OPENGLES3
 #		include <GLES3/gl3platform.h>
 #		include <GLES3/gl3.h>
@@ -256,7 +258,7 @@ namespace bgfx
 #	define _GREMEDY_SETMARKER(_string) glStringMarkerGREMEDY(0, _string)
 #	define _GREMEDY_FRAMETERMINATOR() glFrameTerminatorGREMEDY()
 #else
-#	define _GREMEDY_SETMARKER(_string) do {} while(0)
+#	define _GREMEDY_SETMARKER(_string) do { BX_UNUSED(_string); } while(0)
 #	define _GREMEDY_FRAMETERMINATOR() do {} while(0)
 #endif // BGFX_CONFIG_DEBUG_GREMEDY