Add support for blend operation field.

git-svn-id: svn://svn.code.sf.net/p/irrlicht/code/trunk@3652 dfc29bdd-3216-0410-991c-e03cc46cb475

include/EDriverFeatures.h

@@ -112,6 +112,9 @@ namespace video
 		//! Supports polygon offset/depth bias for avoiding z-fighting
 		EVDF_POLYGON_OFFSET,
 
+		//! Support for different blend functions. Without, only ADD is available
+		EVDF_BLEND_OPERATIONS,
+
 		//! Only used for counting the elements of this enum
 		EVDF_COUNT
 	};

source/Irrlicht/CD3D8Driver.cpp

@@ -605,6 +605,8 @@ bool CD3D8Driver::queryFeature(E_VIDEO_DRIVER_FEATURE feature) const
 		return (Caps.TextureCaps & D3DPTEXTURECAPS_POW2) == 0;
 	case EVDF_COLOR_MASK:
 		return (Caps.PrimitiveMiscCaps & D3DPMISCCAPS_COLORWRITEENABLE) != 0;
+	case EVDF_BLEND_OPERATIONS:
+		return true;
 	default:
 		return false;
 	};
@@ -1562,6 +1564,35 @@ void CD3D8Driver::setBasicRenderStates(const SMaterial& material, const SMateria
 		pID3DDevice->SetRenderState(D3DRS_COLORWRITEENABLE, flag);
 	}
 
+	if (queryFeature(EVDF_BLEND_OPERATIONS) &&
+		(resetAllRenderstates|| lastmaterial.BlendOperation != material.BlendOperation))
+	{
+		if (EBO_NONE)
+			pID3DDevice->SetRenderState(D3DRS_ALPHABLENDENABLE, FALSE);
+		else
+		{
+			pID3DDevice->SetRenderState(D3DRS_ALPHABLENDENABLE, TRUE);
+			switch (material.BlendOperation)
+			{
+			case EBO_MAX:
+				pID3DDevice->SetRenderState(D3DRS_BLENDOP, D3DBLENDOP_MAX);
+				break;
+			case EBO_MIN:
+				pID3DDevice->SetRenderState(D3DRS_BLENDOP, D3DBLENDOP_MIN);
+				break;
+			case EBO_SUBTRACT:
+				pID3DDevice->SetRenderState(D3DRS_BLENDOP, D3DBLENDOP_SUBTRACT);
+				break;
+			case EBO_REVSUBTRACT:
+				pID3DDevice->SetRenderState(D3DRS_BLENDOP, D3DBLENDOP_REVSUBTRACT);
+				break;
+			default:
+				pID3DDevice->SetRenderState(D3DRS_BLENDOP, D3DBLENDOP_ADD);
+				break;
+			}
+		}
+	}
+
 	// Polygon offset
 	if (queryFeature(EVDF_POLYGON_OFFSET) && (resetAllRenderstates ||
 		lastmaterial.PolygonOffsetDirection != material.PolygonOffsetDirection ||

source/Irrlicht/CD3D9Driver.cpp

@@ -666,6 +666,8 @@ bool CD3D9Driver::queryFeature(E_VIDEO_DRIVER_FEATURE feature) const
 		return OcclusionQuerySupport;
 	case EVDF_POLYGON_OFFSET:
 		return (Caps.RasterCaps & (D3DPRASTERCAPS_DEPTHBIAS|D3DPRASTERCAPS_SLOPESCALEDEPTHBIAS)) != 0;
+	case EVDF_BLEND_OPERATIONS:
+		return true;
 	default:
 		return false;
 	};
@@ -2253,6 +2255,35 @@ void CD3D9Driver::setBasicRenderStates(const SMaterial& material, const SMateria
 		pID3DDevice->SetRenderState(D3DRS_COLORWRITEENABLE, flag);
 	}
 
+	if (queryFeature(EVDF_BLEND_OPERATIONS) &&
+		(resetAllRenderstates|| lastmaterial.BlendOperation != material.BlendOperation))
+	{
+		if (EBO_NONE)
+			pID3DDevice->SetRenderState(D3DRS_ALPHABLENDENABLE, FALSE);
+		else
+		{
+			pID3DDevice->SetRenderState(D3DRS_ALPHABLENDENABLE, TRUE);
+			switch (material.BlendOperation)
+			{
+			case EBO_MAX:
+				pID3DDevice->SetRenderState(D3DRS_BLENDOP, D3DBLENDOP_MAX);
+				break;
+			case EBO_MIN:
+				pID3DDevice->SetRenderState(D3DRS_BLENDOP, D3DBLENDOP_MIN);
+				break;
+			case EBO_SUBTRACT:
+				pID3DDevice->SetRenderState(D3DRS_BLENDOP, D3DBLENDOP_SUBTRACT);
+				break;
+			case EBO_REVSUBTRACT:
+				pID3DDevice->SetRenderState(D3DRS_BLENDOP, D3DBLENDOP_REVSUBTRACT);
+				break;
+			default:
+				pID3DDevice->SetRenderState(D3DRS_BLENDOP, D3DBLENDOP_ADD);
+				break;
+			}
+		}
+	}
+
 	// Polygon offset
 	if (queryFeature(EVDF_POLYGON_OFFSET) && (resetAllRenderstates ||
 		lastmaterial.PolygonOffsetDirection != material.PolygonOffsetDirection ||

source/Irrlicht/COpenGLDriver.cpp

@@ -2913,6 +2913,57 @@ void COpenGLDriver::setBasicRenderStates(const SMaterial& material, const SMater
 			(material.ColorMask & ECP_ALPHA)?GL_TRUE:GL_FALSE);
 	}
 
+	if (queryFeature(EVDF_BLEND_OPERATIONS) &&
+		(resetAllRenderStates|| lastmaterial.BlendOperation != material.BlendOperation))
+	{
+		if (EBO_NONE)
+			glDisable(GL_BLEND);
+		else
+		{
+			glEnable(GL_BLEND);
+#if defined(GL_EXT_blend_subtract) || defined(GL_EXT_blend_minmax) || defined(GL_EXT_blend_logic_op) || defined(GL_VERSION_1_2)
+			switch (material.BlendOperation)
+			{
+			case EBO_MAX:
+#if defined(GL_EXT_blend_minmax)
+				extGlBlendEquation(GL_MAX_EXT);
+#elif defined(GL_VERSION_1_2)
+				extGlBlendEquation(GL_MAX);
+#endif
+				break;
+			case EBO_MIN:
+#if defined(GL_EXT_blend_minmax)
+				extGlBlendEquation(GL_MIN_EXT);
+#elif defined(GL_VERSION_1_2)
+				extGlBlendEquation(GL_MIN);
+#endif
+				break;
+			case EBO_SUBTRACT:
+#if defined(GL_EXT_blend_subtract)
+				extGlBlendEquation(GL_FUNC_SUBTRACT_EXT);
+#elif defined(GL_VERSION_1_2)
+				extGlBlendEquation(GL_FUNC_SUBTRACT);
+#endif
+				break;
+			case EBO_REVSUBTRACT:
+#if defined(GL_EXT_blend_subtract)
+				extGlBlendEquation(GL_FUNC_REVERSE_SUBTRACT_EXT);
+#elif defined(GL_VERSION_1_2)
+				extGlBlendEquation(GL_FUNC_REVERSE_SUBTRACT);
+#endif
+				break;
+			default:
+#if defined(GL_EXT_blend_subtract) || defined(GL_EXT_blend_minmax) || defined(GL_EXT_blend_logic_op)
+				extGlBlendEquation(GL_FUNC_ADD_EXT);
+#elif defined(GL_VERSION_1_2)
+				extGlBlendEquation(GL_FUNC_ADD);
+#endif
+				break;
+			}
+#endif
+		}
+	}
+
 	// Polygon Offset
 	if (queryFeature(EVDF_POLYGON_OFFSET) && (resetAllRenderStates ||
 		lastmaterial.PolygonOffsetDirection != material.PolygonOffsetDirection ||

source/Irrlicht/COpenGLExtensionHandler.cpp

@@ -824,6 +824,9 @@ bool COpenGLExtensionHandler::queryFeature(E_VIDEO_DRIVER_FEATURE feature) const
 	case EVDF_POLYGON_OFFSET:
 		// both features supported with OpenGL 1.1
 		return Version>=110;
+	case EVDF_BLEND_OPERATIONS:
+		return (Version>=120) || FeatureAvailable[IRR_EXT_blend_minmax] ||
+			FeatureAvailable[IRR_EXT_blend_subtract] || FeatureAvailable[IRR_EXT_blend_logic_op];
 	default:
 		return false;
 	};

source/Irrlicht/COpenGLExtensionHandler.h

@@ -1049,6 +1049,9 @@ class COpenGLExtensionHandler
 	// generic vsync setting method for several extensions
 	void extGlSwapInterval(int interval);
 
+	// blend operations
+	void extGlBlendEquation(GLenum mode);
+
 	// the global feature array
 	bool FeatureAvailable[IRR_OpenGL_Feature_Count];
 
@@ -1157,6 +1160,8 @@ class COpenGLExtensionHandler
 		PFNGLENDOCCLUSIONQUERYNVPROC pGlEndOcclusionQueryNV;
 		PFNGLGETOCCLUSIONQUERYIVNVPROC pGlGetOcclusionQueryivNV;
 		PFNGLGETOCCLUSIONQUERYUIVNVPROC pGlGetOcclusionQueryuivNV;
+		PFNGLBLENDEQUATIONEXTPROC pGlBlendEquationEXT;
+		PFNGLBLENDEQUATIONPROC pGlBlendEquation;
 		#if defined(WGL_EXT_swap_control)
 		PFNWGLSWAPINTERVALEXTPROC pWglSwapIntervalEXT;
 		#endif
@@ -2355,6 +2360,22 @@ inline void COpenGLExtensionHandler::extGlSwapInterval(int interval)
 #endif
 }
 
+inline void COpenGLExtensionHandler::extGlBlendEquation(GLenum mode)
+{
+#ifdef _IRR_OPENGL_USE_EXTPOINTER_
+	if (pGlBlendEquation)
+		pGlBlendEquation(mode);
+	else if (pGlBlendEquationEXT)
+		pGlBlendEquationEXT(mode);
+#elif defined(GL_EXT_blend_minmax) || defined(GL_EXT_blend_subtract) || defined(GL_EXT_blend_logic_op)
+	glBlendEquationEXT(mode);
+#elif defined(GL_VERSION_1_2)
+	glBlendEquation(mode);
+#else
+	os::Printer::log("glBlendEquation not supported", ELL_ERROR);
+#endif
+}
+
 
 }
 }