Convert gltk.Program to a class template to generate specialized program classes.

src/gltk/program.d

@@ -3,10 +3,21 @@ import gltk.shader;
 import derelict.opengl;
 import std.string;
 
-class Program
+class Program(uniforms...)
 {
+    /* The number of template parameters must be a multiple of 2. */
+    static assert((uniforms.length % 2) == 0);
+
     private GLuint m_id;
 
+    static foreach (i, v; uniforms)
+    {
+        static if ((i % 2) == 0)
+        {
+            mixin("private GLint m_uniform_" ~ v ~ ";");
+        }
+    }
+
     this(Args...)(Args args)
     {
         m_id = glCreateProgram();
@@ -35,7 +46,7 @@ class Program
         glBindAttribLocation(m_id, index, name.toStringz());
     }
 
-    void link() const
+    void link()
     {
         glLinkProgram(m_id);
 
@@ -56,6 +67,14 @@ class Program
             }
             throw new Exception(message);
         }
+
+        static foreach(i, v; uniforms)
+        {
+            static if ((i % 2) == 0)
+            {
+                mixin("m_uniform_" ~ v ~ " = glGetUniformLocation(m_id, \"" ~ v ~ "\");");
+            }
+        }
     }
 
     GLint get_uniform_location(string uniform_name) const
@@ -63,7 +82,7 @@ class Program
         return glGetUniformLocation(m_id, uniform_name.toStringz());
     }
 
-    void get_uniform_locations(Args...)(string uniform_name, GLint * uniform_location, Args args)
+    void get_uniform_locations(Args...)(string uniform_name, GLint * uniform_location, Args args) const
     {
         *uniform_location = get_uniform_location(uniform_name);
         static if (args.length > 0u)
@@ -82,19 +101,80 @@ class Program
         glUseProgram(m_id);
     }
 
-    private void build(Args...)(Shader s, Args args) const
+    private static string uniform_param_decl_list(string spec)
+    {
+        int count = spec[0] - '0';
+        string type;
+        if (spec[1] == 'i')
+        {
+            type = "GLint";
+        }
+        else if (spec[1..2] == "ui")
+        {
+            type = "GLuint";
+        }
+        else if (spec[1] == 'f')
+        {
+            type = "GLfloat";
+        }
+        assert(type != "");
+        if (spec[$ - 1] == 'v')
+        {
+            return "uint count, const " ~ type ~ " * v";
+        }
+        else
+        {
+            string[] decls;
+            for (int i = 0; i < count; i++)
+            {
+                decls ~= type ~ " v" ~ cast(char)('0' + i);
+            }
+            return decls.join(", ");
+        }
+    }
+
+    private static string uniform_param_list(string spec)
+    {
+        int count = spec[0] - '0';
+        if (spec[$ - 1] == 'v')
+        {
+            return "count, v";
+        }
+        else
+        {
+            string[] vees;
+            for (int i = 0; i < count; i++)
+            {
+                vees ~= "v" ~ cast(char)('0' + i);
+            }
+            return vees.join(", ");
+        }
+    }
+
+    static foreach (i, v; uniforms)
+    {
+        static if ((i % 2) == 0)
+        {
+            mixin("void set_" ~ v ~ "(" ~ uniform_param_decl_list(uniforms[i + 1]) ~ ")"
+                  "{"
+                  "    glUniform" ~ uniforms[i + 1] ~ "(m_uniform_" ~ v ~ ", " ~ uniform_param_list(uniforms[i + 1]) ~ ");"
+                  "}");
+        }
+    }
+
+    private void build(Args...)(Shader s, Args args)
     {
         attach_shader(s);
         build(args);
     }
 
-    private void build(Args...)(string attrib_name, uint index, Args args) const
+    private void build(Args...)(string attrib_name, uint index, Args args)
     {
         bind_attrib_location(attrib_name, index);
         build(args);
     }
 
-    private void build() const
+    private void build()
     {
         link();
     }

src/jes/gui/package.d

@@ -8,11 +8,8 @@ import jes.gui.font;
 class Gui
 {
     jtk.Window[] m_windows;
-    gltk.Program m_text_program;
+    alias TextProgram = gltk.Program!("viewport_size", "2i", "texture", "1i", "color", "4f", "position", "2i");
-    GLint m_viewport_size;
+    TextProgram m_text_program;
-    GLint m_texture;
-    GLint m_color;
-    GLint m_position;
     int width;
     int height;
 
@@ -47,12 +44,7 @@ class Gui
             v_shader.set_source_from_file("share/jes/shaders/text.v.glsl");
             auto f_shader = new gltk.Shader(GL_FRAGMENT_SHADER);
             f_shader.set_source_from_file("share/jes/shaders/text.f.glsl");
-            m_text_program = new gltk.Program(v_shader, f_shader, "coords", 0);
+            m_text_program = new TextProgram(v_shader, f_shader, "coords", 0);
-            m_text_program.get_uniform_locations(
-                    "viewport_size", &m_viewport_size,
-                    "texture", &m_texture,
-                    "color", &m_color,
-                    "position", &m_position);
             glActiveTexture(GL_TEXTURE0);
             glEnable(GL_BLEND);
             glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
@@ -93,10 +85,10 @@ class Gui
         auto font = new Font("share/jes/fonts/freefont-ttf-20120503/FreeMono.ttf", 20);
         auto glyph = font.get_glyph('h');
         m_text_program.use();
-        glUniform2i(m_viewport_size, width, height);
+        m_text_program.set_viewport_size(width, height);
-        glUniform1i(m_texture, 0);
+        m_text_program.set_texture(0);
-        glUniform4f(m_color, 1.0, 1.0, 1.0, 1.0);
+        m_text_program.set_color(1.0, 1.0, 1.0, 1.0);
-        glUniform2i(m_position, 10, 10);
+        m_text_program.set_position(100, 10);
         glyph.render();
         m_windows[0].swap_buffers();
     }