Implemented proper approach to rendering all consecutive bitmap text …

…characters of a texture page in one draw call, instead of only up to 8 at a time, using only one texture unit due to the shared texture page. Due to this change OpenGL users can now enjoy the fps boosts as well since the OpenGL implementation only supports 1 texture at a time. Nets a ~35-50% fps boost in an average song pack at music select.

src/BitmapText.cpp

@@ -421,81 +421,52 @@ void BitmapText::DrawChars( bool bUseStrokeTexture )
 		}
 	}
 
-	TextureUnit textureUnit = TextureUnit_1;
 	bool haveTextures = false;
-	int texUnit = 0;
 	int startingPoint = iStartGlyph;
 
 	DISPLAY->ClearAllTextures();
-	for( int start = iStartGlyph; start < iEndGlyph; )
+	for ( int start = iStartGlyph; start < iEndGlyph; )
 	{
 		int end = start;
-		while( end < iEndGlyph  &&  m_vpFontPageTextures[end] == m_vpFontPageTextures[start] )
+		while (end < iEndGlyph  &&  m_vpFontPageTextures[end] == m_vpFontPageTextures[start])
 			end++;
 
-		bool bHaveATexture = !bUseStrokeTexture  ||  (bUseStrokeTexture && m_vpFontPageTextures[start]->m_pTextureStroke);
-		if( bHaveATexture )
+		bool bHaveATexture = !bUseStrokeTexture || (bUseStrokeTexture && m_vpFontPageTextures[start]->m_pTextureStroke);
+		if (bHaveATexture)
 		{
-			haveTextures = true;
-
-			switch ( texUnit )
+			if (!haveTextures)
 			{
-			case 0:
-				textureUnit = TextureUnit_1;
-				break;
-			case 1:
-				textureUnit = TextureUnit_2;
-				break;
-			case 2:
-				textureUnit = TextureUnit_3;
-				break;
-			case 3:
-				textureUnit = TextureUnit_4;
-				break;
-			case 4:
-				textureUnit = TextureUnit_5;
-				break;
-			case 5:
-				textureUnit = TextureUnit_6;
-				break;
-			case 6:
-				textureUnit = TextureUnit_7;
-				break;
-			case 7:
-				textureUnit = TextureUnit_8;
-				break;
-			}
-
-			if ( bUseStrokeTexture )
-				DISPLAY->SetTexture( textureUnit, m_vpFontPageTextures[start]->m_pTextureStroke->GetTexHandle() );
-			else
-				DISPLAY->SetTexture( textureUnit, m_vpFontPageTextures[start]->m_pTextureMain->GetTexHandle() );
+				haveTextures = true;
 
-			texUnit++;
+				if (bUseStrokeTexture)
+					DISPLAY->SetTexture(TextureUnit_1, m_vpFontPageTextures[start]->m_pTextureStroke->GetTexHandle());
+				else
+					DISPLAY->SetTexture(TextureUnit_1, m_vpFontPageTextures[start]->m_pTextureMain->GetTexHandle());
+			}
 
 			// Don't bother setting texture render states for text. We never go outside of 0..1.
-			/* We should call SetTextureRenderStates because it does more than just setting 
-			 * the texture wrapping state. If setting the wrapping state is found to be slow, 
+			/* We should call SetTextureRenderStates because it does more than just setting
+			 * the texture wrapping state. If setting the wrapping state is found to be slow,
 			 * there should probably be a "don't care" texture wrapping mode set in Actor. -Chris */
-			 
-			// This is SLOW. We need to do something else about this. -Colby
-			//Actor::SetTextureRenderStates();
+
+			 // This is SLOW. We need to do something else about this. -Colby
+			 //Actor::SetTextureRenderStates();
 		}
 
 		// Characters from different texture pages cannot be bundled together in the same render call
 		bool renderNow = false;
 		if ( haveTextures && end < m_vpFontPageTextures.size() && m_vpFontPageTextures[start]->m_pTextureMain != m_vpFontPageTextures[end]->m_pTextureMain )
+		{
 			renderNow = true;
+		}
 
-		// Render if we can't store any more textures without running into software or hardware limitations
-		if ( haveTextures && (((renderNow || end >= iEndGlyph) || texUnit == 8) || (texUnit == DISPLAY->GetNumTextureUnits() || !PREFSMAN->m_bAllowMultitexture )) )
+		if ( haveTextures && (renderNow || end >= iEndGlyph) )
 		{
 			DISPLAY->DrawQuads(&m_aVertices[startingPoint * 4], (end - startingPoint) * 4);
 
 			// Setup for the next render pass
 			DISPLAY->ClearAllTextures();
 			startingPoint = end;
-			texUnit = 0;
 			haveTextures = false;
 		}