Added Shader:getExternVariable(name).

Returns the base type name ('float', 'image', etc.), the number of components (2 for a vec2), and number of array elements (1 for a non-array variable) for the extern variable with the specified name in the shader.

Returns nil if the variable either doesn't exist or was optimized out by the driver's shader compiler.

src/modules/graphics/opengl/Shader.cpp

@@ -255,7 +255,7 @@ void Shader::mapActiveUniforms()
 		}
 
 		// If this is a built-in (LOVE-created) uniform, store the location.
-		BuiltinExtern builtin;
+		BuiltinUniform builtin;
 		if (builtinNames.find(u.name.c_str(), builtin))
 			builtinUniforms[int(builtin)] = u.location;
 
@@ -660,19 +660,36 @@ int Shader::getTextureUnit(const std::string &name)
 	return texunit;
 }
 
+Shader::UniformType Shader::getExternVariable(const std::string &name, int &components, int &count)
+{
+	auto it = uniforms.find(name);
+
+	if (it == uniforms.end())
+	{
+		components = 0;
+		count = 0;
+		return UNIFORM_UNKNOWN;
+	}
+
+	components = getUniformTypeSize(it->second.type);
+	count = (int) it->second.count;
+
+	return it->second.baseType;
+}
+
 bool Shader::hasVertexAttrib(OpenGL::VertexAttrib attrib) const
 {
 	return vertexAttributes[int(attrib)] != -1;
 }
 
-bool Shader::hasBuiltinExtern(BuiltinExtern builtin) const
+bool Shader::hasBuiltinUniform(BuiltinUniform builtin) const
 {
 	return builtinUniforms[int(builtin)] != -1;
 }
 
-bool Shader::sendBuiltinFloat(BuiltinExtern builtin, int size, const GLfloat *vec, int count)
+bool Shader::sendBuiltinFloat(BuiltinUniform builtin, int size, const GLfloat *vec, int count)
 {
-	if (!hasBuiltinExtern(builtin))
+	if (!hasBuiltinUniform(builtin))
 		return false;
 
 	GLint location = builtinUniforms[int(builtin)];
@@ -766,6 +783,16 @@ bool Shader::isSupported()
 	return GLEE_VERSION_2_0 && getGLSLVersion() >= "1.2";
 }
 
+bool Shader::getConstant(const char *in, UniformType &out)
+{
+	return uniformTypes.find(in, out);
+}
+
+bool Shader::getConstant(UniformType in, const char *&out)
+{
+	return uniformTypes.find(in, out);
+}
+
 StringMap<Shader::ShaderType, Shader::TYPE_MAX_ENUM>::Entry Shader::typeNameEntries[] =
 {
 	{"vertex", Shader::TYPE_VERTEX},
@@ -774,6 +801,17 @@ StringMap<Shader::ShaderType, Shader::TYPE_MAX_ENUM>::Entry Shader::typeNameEntr
 
 StringMap<Shader::ShaderType, Shader::TYPE_MAX_ENUM> Shader::typeNames(Shader::typeNameEntries, sizeof(Shader::typeNameEntries));
 
+StringMap<Shader::UniformType, Shader::UNIFORM_MAX_ENUM>::Entry Shader::uniformTypeEntries[] =
+{
+	{"float", Shader::UNIFORM_FLOAT},
+	{"int", Shader::UNIFORM_INT},
+	{"bool", Shader::UNIFORM_BOOL},
+	{"image", Shader::UNIFORM_SAMPLER},
+	{"unknown", Shader::UNIFORM_UNKNOWN},
+};
+
+StringMap<Shader::UniformType, Shader::UNIFORM_MAX_ENUM> Shader::uniformTypes(Shader::uniformTypeEntries, sizeof(Shader::uniformTypeEntries));
+
 StringMap<OpenGL::VertexAttrib, OpenGL::ATTRIB_MAX_ENUM>::Entry Shader::attribNameEntries[] =
 {
 	{"love_PseudoInstanceID", OpenGL::ATTRIB_PSEUDO_INSTANCE_ID},
@@ -781,12 +819,12 @@ StringMap<OpenGL::VertexAttrib, OpenGL::ATTRIB_MAX_ENUM>::Entry Shader::attribNa
 
 StringMap<OpenGL::VertexAttrib, OpenGL::ATTRIB_MAX_ENUM> Shader::attribNames(Shader::attribNameEntries, sizeof(Shader::attribNameEntries));
 
-StringMap<Shader::BuiltinExtern, Shader::BUILTIN_MAX_ENUM>::Entry Shader::builtinNameEntries[] =
+StringMap<Shader::BuiltinUniform, Shader::BUILTIN_MAX_ENUM>::Entry Shader::builtinNameEntries[] =
 {
 	{"love_ScreenSize", Shader::BUILTIN_SCREEN_SIZE},
 };
 
-StringMap<Shader::BuiltinExtern, Shader::BUILTIN_MAX_ENUM> Shader::builtinNames(Shader::builtinNameEntries, sizeof(Shader::builtinNameEntries));
+StringMap<Shader::BuiltinUniform, Shader::BUILTIN_MAX_ENUM> Shader::builtinNames(Shader::builtinNameEntries, sizeof(Shader::builtinNameEntries));
 
 } // opengl
 } // graphics