add Program.get_uniform_location()

include/glcxx/Program.hpp

@@ -54,6 +54,11 @@ namespace glcxx
                 bind_attributes(args...);
             }
 
+            GLint get_uniform_location(const char * uniform_name)
+            {
+                return glGetUniformLocation(m_id, uniform_name);
+            }
+
         protected:
             void allocate();
 

src/glcxx/Program.cpp

@@ -49,16 +49,4 @@ namespace glcxx
             throw Error(message);
         }
     }
-
-#if 0
-    for (;;)
-    {
-        const char *uniform_name = va_arg(va, const char *);
-        if (uniform_name == NULL)
-            break;
-        GLint loc = glGetUniformLocation(m_id, uniform_name);
-        m_uniform_locations.push_back(loc);
-        m_uniform_location_names[uniform_name] = loc;
-    }
-#endif
 }

test/frag.glsl

@@ -1,4 +1,6 @@
+uniform vec4 color;
+
 void main(void)
 {
-    gl_FragColor = vec4(0.5, 0.1, 0.9, 1.0);
+    gl_FragColor = color;
 }

test/test.cpp

@@ -48,6 +48,8 @@ void display(SDL_Window * window)
     glEnableVertexAttribArray(0);
     glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 2 * sizeof(GLfloat), NULL);
     program->use();
+    GLint uniform_location = program->get_uniform_location("color");
+    glUniform4f(uniform_location, 1.0, 0.6, 0.2, 1.0);
     glDrawArrays(GL_TRIANGLE_FAN, 0, 4);
     SDL_GL_SwapWindow(window);
 }