[Performous-commit] Tapio Vierros : Provide a nice interface for uniforms in Shader class.

[Tapio V. <aa...@us...>]

Module: performous
Branch: opengl2
Commit: 801c43948ef51a3c5a24710c5e0b1ce508da07ac

Author: Tapio Vierros <tap...@gm...>
Date:   Sat Nov  6 21:06:57 2010 +0200

Provide a nice interface for uniforms in Shader class.

---

 game/glshader.cc     |   15 ++++++++-------
 game/glshader.hh     |   28 ++++++++++++++++++++++------
 game/screen_intro.cc |    2 +-
 game/surface.hh      |   11 +++++------
 4 files changed, 36 insertions(+), 20 deletions(-)

diff --git a/game/glshader.cc b/game/glshader.cc
index 3d0f965..3a38510 100644
--- a/game/glshader.cc
+++ b/game/glshader.cc
@@ -53,6 +53,7 @@ Shader::Shader(const std::string& vert_path, const std::string& frag_path, bool
 
 
 Shader::~Shader() {
+	shaders[program] = NULL;
 	glDeleteProgram(program);
 	glDeleteShader(vert_shader);
 	glDeleteShader(frag_shader);
@@ -109,13 +110,6 @@ void Shader::loadFromMemory(const char* vert_source, const char* frag_source, bo
 	}
 	glutil::GLErrorChecker linkerror("Shader::loadFromMemory - glLinkProgram");
 
-	// Cache uniform locations
-	tex = glGetUniformLocation(program, "tex");
-	texRect = glGetUniformLocation(program, "texRect");
-	texMode = glGetUniformLocation(program, "texMode");
-	anim = glGetUniformLocation(program, "anim");
-	glutil::GLErrorChecker uniformerror("Shader::loadFromMemory - glGetUniformLocation");
-
 	shaders[program] = this;
 
 	if (use) bind();
@@ -128,6 +122,13 @@ void Shader::bind() {
 }
 
 
+GLint Shader::operator[](const std::string& uniform) {
+	UniformMap::iterator it = uniforms.find(uniform);
+	if (it == uniforms.end())
+		it->second = glGetUniformLocation(program, uniform.c_str());
+	return it->second;
+}
+
 
 void loadShaders() {
 	Window::shader.reset(new Shader(getThemePath("shaders/core.vert"), getThemePath("shaders/core.frag"), true));
diff --git a/game/glshader.hh b/game/glshader.hh
index 71c285d..1499654 100644
--- a/game/glshader.hh
+++ b/game/glshader.hh
@@ -19,11 +19,19 @@ struct Shader: public boost::noncopyable {
 	/** Binds the shader into use. */
 	void bind();
 
-	GLuint program, vert_shader, frag_shader; ///< shader object ids
-	// TODO: Should probably use an std::map for these and cache on-the-fly/on-demand.
-	//       Also provide a nice access to setting the uniform.
-	GLint tex, texRect, texMode, anim; ///< uniform locations
-	int gl_response;
+	/** Get uniform location. Uses caching internally. */
+	GLint operator[](const std::string& uniform);
+
+	/** Allow setting uniforms in a chain. Shader needs to be in use.*/
+
+	Shader& setUniform(const std::string& uniform, int value) {
+		glUniform1i((*this)[uniform], value);
+		return *this;
+	}
+	Shader& setUniform(const std::string& uniform, float value) {
+		glUniform1f((*this)[uniform], value);
+		return *this;
+	}
 
 	// Some operators
 	operator bool() const { return program != 0; }
@@ -37,8 +45,15 @@ struct Shader: public boost::noncopyable {
 		return shaders[i];
 	}
 
+	GLuint program, vert_shader, frag_shader; ///< shader object ids
+	int gl_response;
+
+  private:
+	typedef std::map<std::string, GLint> UniformMap;
+	UniformMap uniforms; ///< Cached uniform locations, use operator[] to access
+
 	typedef std::map<GLint, Shader*> ShaderMap;
-	static ShaderMap shaders;
+	static ShaderMap shaders; ///< Shader objects for reverse look-up by id
 };
 
 
@@ -49,6 +64,7 @@ struct UseShader {
 		new_shader.bind();
 	}
 	~UseShader() { glUseProgram(m_old); }
+
   private:
 	GLint m_old;
 };
diff --git a/game/screen_intro.cc b/game/screen_intro.cc
index 61e9023..ccca31b 100644
--- a/game/screen_intro.cc
+++ b/game/screen_intro.cc
@@ -116,7 +116,7 @@ void ScreenIntro::draw() {
 	{
 		UseShader s(*ThemeIntro::shader);
 		float anim = std::abs((((SDL_GetTicks() % 10000) / 10000.f) - 0.5f) * 2.0f);
-		glUniform1f(ThemeIntro::shader->anim, anim);
+		ThemeIntro::shader->setUniform("anim", anim);
 		theme->bg.draw();
 	}
 	if (m_menu.current().image) m_menu.current().image->draw();
diff --git a/game/surface.hh b/game/surface.hh
index 2a9ef6b..f173515 100644
--- a/game/surface.hh
+++ b/game/surface.hh
@@ -122,19 +122,18 @@ class UseTexture: boost::noncopyable {
 	/// constructor
 	template <GLenum Type> UseTexture(OpenGLTexture<Type> const& s):
 	  m_shader(*Shader::current()) {
-		glUniform1i(m_shader.tex, 0);
-		glUniform1i(m_shader.texRect, 1);
+		m_shader.setUniform("tex", 0).setUniform("texRect", 1);
 
 		switch (Type) {
-		  case GL_TEXTURE_2D:             glActiveTexture(GL_TEXTURE0); glUniform1i(m_shader.texMode, 1); break;
-		  case GL_TEXTURE_RECTANGLE_ARB:  glActiveTexture(GL_TEXTURE0+1); glUniform1i(m_shader.texMode, 2); break;
-		  default:                        glUniform1i(m_shader.texMode, 3); break;
+		  case GL_TEXTURE_2D:             glActiveTexture(GL_TEXTURE0); m_shader.setUniform("texMode", 1); break;
+		  case GL_TEXTURE_RECTANGLE_ARB:  glActiveTexture(GL_TEXTURE0+1); m_shader.setUniform("texMode", 2); break;
+		  default:                        m_shader.setUniform("texMode", 3); break;
 		}
 
 		glBindTexture(Type, s.id());
 	}
 	~UseTexture() {
-		glUniform1i(m_shader.texMode, 0);
+		m_shader.setUniform("texMode", 0);
 	}
 
   private: