Added alpha-mapping support

Former-commit-id: ba4598e9e5efc47e04e72dc709d64d214d77e9a1

src/Nazara/Renderer/GLSLShader.cpp

@@ -61,10 +61,12 @@ bool NzGLSLShader::Compile()
 		static NzString successStr("Linkage successful");
 		m_log = successStr;
 
+		// Pour éviter de se tromper entre le nom et la constante
 		#define CacheUniform(name) m_uniformLocations[nzShaderUniform_##name] = GetUniformLocation(#name)
 
 		CacheUniform(CameraPosition);
 		CacheUniform(LightCount);
+		CacheUniform(MaterialAlphaMap);
 		CacheUniform(MaterialAmbient);
 		CacheUniform(MaterialDiffuse);
 		CacheUniform(MaterialDiffuseMap);

src/Nazara/Renderer/Material.cpp

@@ -31,6 +31,7 @@ NzMaterial::NzMaterial(NzMaterial&& material)
 	Copy(material);
 
 	// Nous "volons" la référence du matériau
+	material.m_alphaMap = nullptr;
 	material.m_customShader = nullptr;
 	material.m_diffuseMap = nullptr;
 	material.m_emissiveMap = nullptr;
@@ -46,6 +47,19 @@ void NzMaterial::Apply(const NzShader* shader) const
 	int shininessLocation = shader->GetUniformLocation(nzShaderUniform_MaterialShininess);
 	int specularColorLocation = shader->GetUniformLocation(nzShaderUniform_MaterialSpecular);
 
+	if (m_alphaMap)
+	{
+		int alphaMapLocation = shader->GetUniformLocation(nzShaderUniform_MaterialAlphaMap);
+		if (alphaMapLocation != -1)
+		{
+			nzUInt8 textureUnit;
+			if (shader->SendTexture(alphaMapLocation, m_alphaMap, &textureUnit))
+				NzRenderer::SetTextureSampler(textureUnit, m_diffuseSampler);
+			else
+				NazaraWarning("Failed to send diffuse map");
+		}
+	}
+
 	if (ambientColorLocation != -1)
 		shader->SendColor(ambientColorLocation, m_ambientColor);
 
@@ -327,6 +341,7 @@ bool NzMaterial::LoadFromStream(NzInputStream& stream, const NzMaterialParams& p
 
 void NzMaterial::Reset()
 {
+	m_alphaMap.Reset();
 	m_customShader.Reset();
 	m_diffuseMap.Reset();
 	m_emissiveMap.Reset();
@@ -353,6 +368,32 @@ void NzMaterial::Reset()
 	m_zWriteEnabled = true;
 }
 
+bool NzMaterial::SetAlphaMap(const NzString& texturePath)
+{
+	std::unique_ptr<NzTexture> texture(new NzTexture);
+	if (!texture->LoadFromFile(texturePath))
+	{
+		NazaraError("Failed to load texture from \"" + texturePath + '"');
+		return false;
+	}
+
+	texture->SetPersistent(false);
+
+	SetAlphaMap(texture.get());
+	texture.release();
+
+	return true;
+}
+
+void NzMaterial::SetAlphaMap(NzTexture* map)
+{
+	m_alphaMap = map;
+	if (m_alphaMap)
+		m_shaderFlags |= nzShaderFlags_AlphaMapping;
+	else
+		m_shaderFlags &= ~nzShaderFlags_AlphaMapping;
+}
+
 void NzMaterial::SetAmbientColor(const NzColor& ambient)
 {
 	m_ambientColor = ambient;
@@ -551,6 +592,7 @@ NzMaterial& NzMaterial::operator=(NzMaterial&& material)
 	Copy(material);
 
 	// Comme ça nous volons la référence du matériau
+	material.m_alphaMap = nullptr;
 	material.m_customShader = nullptr;
 	material.m_diffuseMap = nullptr;
 	material.m_emissiveMap = nullptr;
@@ -581,6 +623,7 @@ NzMaterial* NzMaterial::GetDefault()
 
 void NzMaterial::Copy(const NzMaterial& material)
 {
+	m_alphaMap.Reset();
 	m_customShader.Reset();
 	m_diffuseMap.Reset();
 	m_emissiveMap.Reset();
@@ -591,6 +634,7 @@ void NzMaterial::Copy(const NzMaterial& material)
 	std::memcpy(this, &material, sizeof(NzMaterial)); // Autorisé dans notre cas, et bien plus rapide
 
 	// Ensuite une petite astuce pour récupérer correctement les références
+	m_alphaMap.Release();
 	m_customShader.Release();
 	m_diffuseMap.Release();
 	m_emissiveMap.Release();
@@ -598,6 +642,7 @@ void NzMaterial::Copy(const NzMaterial& material)
 	m_normalMap.Release();
 	m_specularMap.Release();
 
+	m_alphaMap = material.m_alphaMap;
 	m_customShader = material.m_customShader;
 	m_diffuseMap = material.m_diffuseMap;
 	m_heightMap = material.m_heightMap;

src/Nazara/Renderer/ShaderBuilder.cpp

@@ -75,6 +75,9 @@ namespace
 			              "uniform vec4 MaterialAmbient;\n";
 		}
 
+		if (flags & nzShaderFlags_AlphaMapping)
+			sourceCode += "uniform sampler2D MaterialAlphaMap;\n";
+
 		if ((flags & nzShaderFlags_DiffuseMapping) == 0 || flags & nzShaderFlags_Lighting)
 			sourceCode += "uniform vec4 MaterialDiffuse;\n";
 
@@ -280,17 +283,27 @@ 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 += "vec3 emission = vec3(" + textureLookupKW + "(MaterialEmissiveMap, vTexCoord));\n"
-				               + fragmentColorKW + " = vec4(mix(lighting, emission, length(emission)), MaterialDiffuse.a);";
+				               + fragmentColorKW + " = vec4(mix(lighting, emission, length(emission)), alpha);\n";
 				///NOTE: Pour un shader avec un coût réduit avec une qualité moyenne, il est possible de remplacer "length(emission)" par "dot(emission, emission)"
 			}
 			else
-				sourceCode += fragmentColorKW + " = vec4(lighting, MaterialDiffuse.a);";
+				sourceCode += fragmentColorKW + " = vec4(lighting, alpha);\n";
 		}
 		else if (flags & nzShaderFlags_DiffuseMapping)
-			sourceCode += fragmentColorKW + " = " + textureLookupKW + "(MaterialDiffuseMap, vTexCoord);\n";
+		{
+			if (flags & nzShaderFlags_AlphaMapping)
+				sourceCode += fragmentColorKW + " = vec4(" + textureLookupKW + "(MaterialDiffuseMap, vTexCoord).rgb, " + textureLookupKW + "(MaterialAlphaMap, vTexCoord).r);\n";
+			else
+				sourceCode += fragmentColorKW + " = " + textureLookupKW + "(MaterialDiffuseMap, vTexCoord);\n";
+		}
 		else
 			sourceCode += fragmentColorKW + " = MaterialDiffuse;\n";