Internally compose and pass an array of shader source codes to OpenGL, instead of relying on #line to make sure the line number is correct for shader error messages (resolves issue #882)

src/modules/graphics/opengl/Shader.cpp

@@ -66,21 +66,25 @@ Shader *Shader::current = nullptr;
 GLint Shader::maxTexUnits = 0;
 std::vector<int> Shader::textureCounters;
 
-Shader::Shader(const ShaderSources &sources)
-	: shaderSources(sources)
-	, program(0)
+Shader::Shader(const std::vector<std::string> &vertcode, const std::vector<std::string> &pixelcode)
+	: program(0)
 	, builtinUniforms()
 	, vertexAttributes()
 	, lastCanvas((Canvas *) -1)
 	, lastViewport()
 {
-	if (shaderSources.empty())
+	if (vertcode.empty() && pixelcode.empty())
 		throw love::Exception("Cannot create shader: no source code!");
 
+	shaderSources[TYPE_VERTEX] = vertcode;
+	shaderSources[TYPE_PIXEL] = pixelcode;
+
 	if (maxTexUnits <= 0)
 	{
 		GLint maxtexunits;
 		glGetIntegerv(GL_MAX_COMBINED_TEXTURE_IMAGE_UNITS, &maxtexunits);
+
+		// TU 0 is never used for stored Shader images.
 		maxTexUnits = std::max(maxtexunits - 1, 0);
 	}
 
@@ -106,7 +110,7 @@ Shader::~Shader()
 	unloadVolatile();
 }
 
-GLuint Shader::compileCode(ShaderType type, const std::string &code)
+GLuint Shader::compileCode(ShaderType type, const std::vector<std::string> &code)
 {
 	GLenum glshadertype;
 	const char *typestr;
@@ -142,9 +146,18 @@ GLuint Shader::compileCode(ShaderType type, const std::string &code)
 			throw love::Exception("Cannot create %s shader object.", typestr);
 	}
 
-	const char *src = code.c_str();
-	size_t srclen = code.length();
-	glShaderSource(shaderid, 1, (const GLchar **)&src, (GLint *)&srclen);
+	std::vector<const GLchar *> codelist;
+	std::vector<GLint> lengthlist;
+
+	for (size_t i = 0; i < code.size(); i++)
+	{
+		codelist.push_back((const GLchar *) code[i].c_str());
+		lengthlist.push_back((GLint) code[i].length());
+	}
+
+	// The code parameter is a list of source code "files." We can hand them
+	// all to OpenGL at once using glShaderSource.
+	glShaderSource(shaderid, codelist.size(), &codelist[0], &lengthlist[0]);
 
 	glCompileShader(shaderid);
 
@@ -276,10 +289,12 @@ bool Shader::loadVolatile()
 
 	std::vector<GLuint> shaderids;
 
-	ShaderSources::const_iterator source;
-	for (source = shaderSources.begin(); source != shaderSources.end(); ++source)
+	for (int i = 0; i < (int) TYPE_MAX_ENUM; i++)
 	{
-		GLuint shaderid = compileCode(source->first, source->second);
+		if (shaderSources[i].empty())
+			continue;
+
+		GLuint shaderid = compileCode((ShaderType) i, shaderSources[i]);
 		shaderids.push_back(shaderid);
 	}
 
@@ -288,7 +303,7 @@ bool Shader::loadVolatile()
 
 	createProgram(shaderids);
 
-	// Retreive all active uniform variables in this shader from OpenGL.
+	// Get all active uniform variables in this shader from OpenGL.
 	mapActiveUniforms();
 
 	for (int i = 0; i < int(OpenGL::ATTRIB_MAX_ENUM); i++)