Add Gl.draw_rect().

src/jes/gui/gl.d

@@ -13,24 +13,47 @@ class Gl
     private FlatProgram m_flat_program;
     private TextProgram m_text_program;
     private RectProgram m_rect_program;
+    private gltk.Array m_rect_array;
+    private gltk.Buffer m_rect_buffer;
 
-    this()
+    private void build_flat_program()
     {
         m_flat_program = new FlatProgram(
                 build_shader(GL_VERTEX_SHADER, "share/jes/shaders/flat.v.glsl"),
                 build_shader(GL_FRAGMENT_SHADER, "share/jes/shaders/flat.f.glsl"),
                 "coords", 0);
+    }
 
+    private void build_text_program()
+    {
         m_text_program = new TextProgram(
                 build_shader(GL_VERTEX_SHADER, "share/jes/shaders/text.v.glsl"),
                 build_shader(GL_FRAGMENT_SHADER, "share/jes/shaders/text.f.glsl"),
                 "coords", 0);
+        m_text_program.use();
         m_text_program.set_texture(0);
+    }
 
+    private void build_rect_program()
+    {
         m_rect_program = new RectProgram(
                 build_shader(GL_VERTEX_SHADER, "share/jes/shaders/rect.v.glsl"),
                 build_shader(GL_FRAGMENT_SHADER, "share/jes/shaders/rect.f.glsl"),
                 "coords", 0);
+        m_rect_array = new gltk.Array();
+        m_rect_array.bind();
+        m_rect_buffer = new gltk.Buffer(GL_ARRAY_BUFFER);
+        GLint[] rect_coords = [0, 0,  1, 0,  1, 1,  0, 1];
+        m_rect_buffer.set_buffer_data(GL_STATIC_DRAW, rect_coords);
+        glEnableVertexAttribArray(0);
+        glVertexAttribPointer(0, 2, GL_INT, GL_FALSE, 0, null);
+    }
+
+    this()
+    {
+        build_flat_program();
+        build_text_program();
+        build_rect_program();
 
         glActiveTexture(GL_TEXTURE0);
         glEnable(GL_BLEND);
@@ -57,6 +80,17 @@ class Gl
         glyph.render();
     }
 
+    void draw_rect(int x, int y, int width, int height,
+            float r, float g, float b, float a)
+    {
+        m_rect_array.bind();
+        m_rect_program.use();
+        m_rect_program.set_color(r, g, b, a);
+        m_rect_program.set_position(x, y);
+        m_rect_program.set_size(width, height);
+        glDrawArrays(GL_TRIANGLE_FAN, 0, 4);
+    }
+
     private gltk.Shader build_shader(GLenum shader_type, string filename)
     {
         auto shader = new gltk.Shader(shader_type);

src/jes/gui/window.d

@@ -37,6 +37,7 @@ class Window
     {
         glClearColor(0.5, 0.0, 1.0, 0.0);
         glClear(GL_COLOR_BUFFER_BIT);
+        m_gl.draw_rect(50, 50, 20, 20, 0.0, 0.2, 0.4, 1.0);
         m_gl.draw_character(m_font, 'h', 50, 50, 1.0, 0.9, 0.8, 1.0);
         m_window.swap_buffers();
     }