Fixed an issue with alpha values in 2d opengl mode.

Changed the interpretation of MaterialTypeParam==0 in transparent materials. Before, it was interpreted as 0.5, now it's used as 0 (perfectly smooth transparency). This is slower than the old value, but you can achieve the same effect by specifying 0.5 as MaterialTypeParam.

git-svn-id: svn://svn.code.sf.net/p/irrlicht/code/trunk@1512 dfc29bdd-3216-0410-991c-e03cc46cb475

source/Irrlicht/CD3D8MaterialRenderer.h

@@ -297,11 +297,7 @@ public:
 			pID3DDevice->SetRenderState(D3DRS_SRCBLEND, D3DBLEND_SRCALPHA);
 			pID3DDevice->SetRenderState(D3DRS_DESTBLEND, D3DBLEND_INVSRCALPHA );
 
-			s32 refValue = core::floor32(material.MaterialTypeParam * 255.f);
-			if ( !refValue )
-				refValue = 127; // default value
-
-			pID3DDevice->SetRenderState(D3DRS_ALPHAREF, refValue);
+			pID3DDevice->SetRenderState(D3DRS_ALPHAREF, core::floor32(material.MaterialTypeParam * 255.f));
 			pID3DDevice->SetRenderState(D3DRS_ALPHAFUNC, D3DCMP_GREATEREQUAL);
 			pID3DDevice->SetRenderState(D3DRS_ALPHATESTENABLE, TRUE);
 		}
@@ -348,11 +344,7 @@ public:
 
 			pID3DDevice->SetRenderState(D3DRS_ALPHABLENDENABLE, FALSE);
 
-			s32 refValue = core::floor32(material.MaterialTypeParam * 255.f);
-			if ( !refValue )
-				refValue = 127; // default value
-
-            pID3DDevice->SetRenderState(D3DRS_ALPHAREF,refValue);
+			pID3DDevice->SetRenderState(D3DRS_ALPHAREF, core::floor32(material.MaterialTypeParam * 255.f));
 			pID3DDevice->SetRenderState(D3DRS_ALPHAFUNC, D3DCMP_GREATEREQUAL);
 			pID3DDevice->SetRenderState(D3DRS_ALPHATESTENABLE, TRUE);
 		}

source/Irrlicht/CD3D9MaterialRenderer.h

@@ -322,14 +322,9 @@ public:
 			pID3DDevice->SetRenderState(D3DRS_SRCBLEND, D3DBLEND_SRCALPHA);
 			pID3DDevice->SetRenderState(D3DRS_DESTBLEND, D3DBLEND_INVSRCALPHA );
 
-			s32 refValue = core::floor32(material.MaterialTypeParam * 255.f);
-			if ( !refValue )
-				refValue = 127; // default value
-
-			pID3DDevice->SetRenderState(D3DRS_ALPHAREF, refValue);
+			pID3DDevice->SetRenderState(D3DRS_ALPHAREF, core::floor32(material.MaterialTypeParam * 255.f));
 			pID3DDevice->SetRenderState(D3DRS_ALPHAFUNC, D3DCMP_GREATEREQUAL);
 			pID3DDevice->SetRenderState(D3DRS_ALPHATESTENABLE, TRUE);
-
 		}
 
 		((SMaterial&)material).ZWriteEnable = false;
@@ -376,11 +371,7 @@ public:
 
 			pID3DDevice->SetRenderState(D3DRS_ALPHABLENDENABLE, FALSE);
 
-			s32 refValue = core::floor32(material.MaterialTypeParam * 255);
-			if ( !refValue )
-				refValue = 127; // default value
-
-			pID3DDevice->SetRenderState(D3DRS_ALPHAREF,refValue);
+			pID3DDevice->SetRenderState(D3DRS_ALPHAREF, core::floor32(material.MaterialTypeParam * 255));
 			pID3DDevice->SetRenderState(D3DRS_ALPHAFUNC, D3DCMP_GREATEREQUAL);
 			pID3DDevice->SetRenderState(D3DRS_ALPHATESTENABLE, TRUE);
 		}

source/Irrlicht/COpenGLDriver.cpp

@@ -1922,6 +1922,7 @@ void COpenGLDriver::setRenderStates2DMode(bool alpha, bool texture, bool alphaCh
 	{
 		glEnable(GL_BLEND);
 		glEnable(GL_ALPHA_TEST);
+		glAlphaFunc(GL_GREATER, 0.f);
 	}
 	else
 	{

source/Irrlicht/COpenGLMaterialRenderer.h

@@ -132,6 +132,7 @@ public:
 
 			glBlendFunc( getGLBlend(srcFact), getGLBlend(dstFact) );
 			glEnable(GL_ALPHA_TEST);
+			glAlphaFunc(GL_GREATER, 0.f);
 			glEnable(GL_BLEND);
 
 			if ( getTexelAlpha(srcFact) || getTexelAlpha(dstFact) )
@@ -359,11 +360,7 @@ public:
 			glEnable(GL_BLEND);
 			glEnable(GL_ALPHA_TEST);
 
-			f32 refValue = material.MaterialTypeParam;
-			if ( refValue == 0.0f )
-				refValue = 0.5f;
-
-			glAlphaFunc(GL_GREATER, refValue);
+			glAlphaFunc(GL_GREATER, material.MaterialTypeParam);
 		}
 	}
 
@@ -400,7 +397,7 @@ public:
 		if (material.MaterialType != lastMaterial.MaterialType || resetAllRenderstates)
 		{
 			glEnable(GL_ALPHA_TEST);
-			glAlphaFunc(GL_GREATER, 0.5);
+			glAlphaFunc(GL_GREATER, 0.5f);
 			glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
 		}
 	}