Added Alpha Test

Former-commit-id: 59dc6ef8f1dbff49bb13cf452bf75326ad7a6257

src/Nazara/Renderer/GLSLShader.cpp

@@ -67,6 +67,7 @@ bool NzGLSLShader::Compile()
 		CacheUniform(CameraPosition);
 		CacheUniform(LightCount);
 		CacheUniform(MaterialAlphaMap);
+		CacheUniform(MaterialAlphaThreshold);
 		CacheUniform(MaterialAmbient);
 		CacheUniform(MaterialDiffuse);
 		CacheUniform(MaterialDiffuseMap);

src/Nazara/Renderer/Material.cpp

@@ -42,6 +42,7 @@ NzMaterial::NzMaterial(NzMaterial&& material)
 
 void NzMaterial::Apply(const NzShader* shader) const
 {
+	int alphaThresholdLocation = shader->GetUniformLocation(nzShaderUniform_MaterialAlphaThreshold);
 	int ambientColorLocation = shader->GetUniformLocation(nzShaderUniform_MaterialAmbient);
 	int diffuseColorLocation = shader->GetUniformLocation(nzShaderUniform_MaterialDiffuse);
 	int shininessLocation = shader->GetUniformLocation(nzShaderUniform_MaterialShininess);
@@ -60,6 +61,9 @@ void NzMaterial::Apply(const NzShader* shader) const
 		}
 	}
 
+	if (alphaThresholdLocation != -1)
+		shader->SendFloat(alphaThresholdLocation, m_alphaThreshold);
+
 	if (ambientColorLocation != -1)
 		shader->SendColor(ambientColorLocation, m_ambientColor);
 
@@ -153,6 +157,15 @@ void NzMaterial::Enable(nzRendererParameter renderParameter, bool enable)
 	m_states.parameters[renderParameter] = enable;
 }
 
+void NzMaterial::EnableAlphaTest(bool alphaTest)
+{
+	m_alphaTestEnabled = alphaTest;
+	if (m_alphaTestEnabled)
+		m_shaderFlags |= nzShaderFlags_AlphaTest;
+	else
+		m_shaderFlags &= ~nzShaderFlags_AlphaTest;
+}
+
 void NzMaterial::EnableLighting(bool lighting)
 {
 	m_lightingEnabled = lighting;
@@ -167,6 +180,11 @@ NzTexture* NzMaterial::GetAlphaMap() const
 	return m_alphaMap;
 }
 
+float NzMaterial::GetAlphaThreshold() const
+{
+	return m_alphaThreshold;
+}
+
 NzColor NzMaterial::GetAmbientColor() const
 {
 	return m_ambientColor;
@@ -290,6 +308,11 @@ bool NzMaterial::IsEnabled(nzRendererParameter parameter) const
 	return m_states.parameters[parameter];
 }
 
+bool NzMaterial::IsAlphaTestEnabled() const
+{
+	return m_alphaTestEnabled;
+}
+
 bool NzMaterial::IsLightingEnabled() const
 {
 	return m_lightingEnabled;
@@ -320,6 +343,8 @@ void NzMaterial::Reset()
 	m_normalMap.Reset();
 	m_specularMap.Reset();
 
+	m_alphaThreshold = 0.2f;
+	m_alphaTestEnabled = false;
 	m_ambientColor = NzColor(128, 128, 128);
 	m_diffuseColor = NzColor::White;
 	m_diffuseSampler = NzTextureSampler();
@@ -359,6 +384,11 @@ void NzMaterial::SetAlphaMap(NzTexture* map)
 		m_shaderFlags &= ~nzShaderFlags_AlphaMapping;
 }
 
+void NzMaterial::SetAlphaThreshold(float alphaThreshold)
+{
+	m_alphaThreshold = alphaThreshold;
+}
+
 void NzMaterial::SetAmbientColor(const NzColor& ambient)
 {
 	m_ambientColor = ambient;

src/Nazara/Renderer/ShaderBuilder.cpp

@@ -77,6 +77,9 @@ namespace
 		if (flags & nzShaderFlags_AlphaMapping)
 			sourceCode += "uniform sampler2D MaterialAlphaMap;\n";
 
+		if (flags & nzShaderFlags_AlphaTest)
+			sourceCode += "uniform float MaterialAlphaThreshold;\n";
+
 		sourceCode += "uniform vec4 MaterialDiffuse;\n";
 
 		if (flags & nzShaderFlags_DiffuseMapping)
@@ -128,6 +131,18 @@ namespace
 		sourceCode += "void main()\n"
 		              "{\n";
 
+		sourceCode += "float alpha = MaterialDiffuse.a";
+		if (flags & nzShaderFlags_AlphaMapping)
+			sourceCode += '*' + textureLookupKW + "(MaterialAlphaMap, vTexCoord).r";
+
+		sourceCode += ";\n";
+
+		if (flags & nzShaderFlags_AlphaTest)
+		{
+			sourceCode += "if (alpha < MaterialAlphaThreshold)\n"
+			              "discard;\n";
+		}
+
 		if (flags & nzShaderFlags_Lighting)
 		{
 			sourceCode += "vec3 light = vec3(0.0, 0.0, 0.0);\n";
@@ -281,11 +296,6 @@ namespace
 
 			sourceCode += ";\n";
 
-			if (flags & nzShaderFlags_AlphaMapping)
-				sourceCode += "float alpha = " + textureLookupKW + "(MaterialAlphaMap, vTexCoord).r;\n";
-			else
-				sourceCode += "float alpha = MaterialDiffuse.a;\n";
-
 			if (flags & nzShaderFlags_EmissiveMapping)
 			{
 				sourceCode += "float intensity = light.r*0.3 + light.g*0.59 + light.b*0.11;\n"
@@ -295,16 +305,15 @@ namespace
 			else
 				sourceCode += fragmentColorKW + " = vec4(lighting, alpha);\n";
 		}
-		else if (flags & nzShaderFlags_DiffuseMapping)
-		{
-			sourceCode += fragmentColorKW + " = MaterialDiffuse*";
-			if (flags & nzShaderFlags_AlphaMapping)
-				sourceCode += "vec4(" + textureLookupKW + "(MaterialDiffuseMap, vTexCoord).rgb, " + textureLookupKW + "(MaterialAlphaMap, vTexCoord).r);\n";
-			else
-				sourceCode += textureLookupKW + "(MaterialDiffuseMap, vTexCoord);\n";
-		}
 		else
-			sourceCode += fragmentColorKW + " = MaterialDiffuse;\n";
+		{
+			sourceCode += fragmentColorKW + " = MaterialDiffuse";
+
+			if (flags & nzShaderFlags_DiffuseMapping)
+				sourceCode += "*vec4(" + textureLookupKW + "(MaterialDiffuseMap, vTexCoord).rgb, alpha);\n";
+
+			sourceCode += ";\n";
+		}
 
 		sourceCode += "}\n";