Render the opaque part of texture transparency in the first pass. Fixes numerous transparency related issues in lemans24 and some in ocean hunter. I don't really know if this is the 'correct' way of solving this because the real3d pro-1000 is a complete black box. There is still a lot we don't understand about how it handles transparency.

Src/Graphics/New3D/Model.h

@@ -97,7 +97,7 @@ struct Mesh
 			}
 		}
 		else {
-			if (textureAlpha || polyAlpha) {
+			if (polyAlpha) {
 				return false;
 			}
 		}

Src/Graphics/New3D/New3D.cpp

@@ -312,14 +312,18 @@ void CNew3D::RenderFrame(void)
 		glViewport	(0, 0, m_totalXRes, m_totalYRes);		// clear whole viewport
 		glClear		(GL_DEPTH_BUFFER_BIT|GL_STENCIL_BUFFER_BIT);
 
+		m_r3dShader.DiscardAlpha(true);						// chuck out alpha pixels in texture alpha only polys
 		hasOverlay = RenderScene(pri, false, false);
+		m_r3dShader.DiscardAlpha(false);
 		hasOverlay = RenderScene(pri, false, true);
 
 		if (hasOverlay) {
 			//clear depth buffer and render high priority polys
 			glViewport(0, 0, m_totalXRes, m_totalYRes);		// clear whole viewport
 			glClear(GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);
+			m_r3dShader.DiscardAlpha(true);
 			RenderScene(pri, true, false);
+			m_r3dShader.DiscardAlpha(false);
 			RenderScene(pri, true, true);
 		}
 	}

Src/Graphics/New3D/R3DShader.cpp

@@ -62,6 +62,7 @@ uniform vec2	baseTexSize;
 uniform bool	textureInverted;
 uniform bool	textureAlpha;
 uniform bool	alphaTest;
+uniform bool	discardAlpha;
 
 // general
 uniform vec3	fogColour;
@@ -113,6 +114,12 @@ vec4 GetTextureValue()
 		}
 	}
 
+	if(discardAlpha && textureAlpha) {
+		if (tex1Data.a < 1.0) {
+			discard;
+		}
+	}
+
 	if (textureAlpha == false) {
 		tex1Data.a = 1.0;
 	}
@@ -372,6 +379,7 @@ bool R3DShader::LoadShader(const char* vertexShader, const char* fragmentShader)
 	m_locModelScale		= glGetUniformLocation(m_shaderProgram, "modelScale");
 
 	m_locHardwareStep	= glGetUniformLocation(m_shaderProgram, "hardwareStep");
+	m_locDiscardAlpha	= glGetUniformLocation(m_shaderProgram, "discardAlpha");
 	
 	return success;
 }
@@ -386,6 +394,7 @@ void R3DShader::SetShader(bool enable)
 	if (enable) {
 		glUseProgram(m_shaderProgram);
 		Start();
+		DiscardAlpha(false);	// need some default
 	}
 	else {
 		glUseProgram(0);
@@ -512,4 +521,9 @@ void R3DShader::SetModelStates(const Model* model)
 	m_dirtyModel = false;
 }
 
+void R3DShader::DiscardAlpha(bool discard)
+{
+	glUniform1i(m_locDiscardAlpha, discard);
+}
+
 } // New3D

Src/Graphics/New3D/R3DShader.h

@@ -19,6 +19,7 @@ public:
 	void	Start				();
 	void	SetShader			(bool enable = true);
 	GLint	GetVertexAttribPos	(const char* attrib);
+	void	DiscardAlpha		(bool discard);				// use to remove alpha from texture alpha only polys for 1st pass
 
 private:
 
@@ -93,6 +94,7 @@ private:
 
 	// global uniforms
 	GLint m_locHardwareStep;
+	GLint m_locDiscardAlpha;
 };
 
 } // New3D