Reorganise.

Outputs/OpenGL/Shaders/Rectangle.cpp

@@ -0,0 +1,74 @@
+//
+//  Rectangle.cpp
+//  Clock Signal
+//
+//  Created by Thomas Harte on 11/07/2018.
+//  Copyright © 2018 Thomas Harte. All rights reserved.
+//
+
+#include "Rectangle.hpp"
+
+using namespace Outputs::Display::OpenGL;
+
+Rectangle::Rectangle(const API api, const float x, const float y, const float width, const float height):
+	pixel_shader_(
+		api,
+		R"glsl(
+			in vec2 position;
+			void main(void) {
+				gl_Position = vec4(position, 0.0, 1.0);
+			}
+		)glsl",
+		R"glsl(
+			uniform vec4 colour;
+			out vec4 fragColour;
+
+			void main(void) {
+				fragColour = colour;
+			}
+		)glsl"
+	){
+	pixel_shader_.bind();
+
+	test_gl([&]{ glGenVertexArrays(1, &drawing_vertex_array_); });
+	test_gl([&]{ glGenBuffers(1, &drawing_array_buffer_); });
+
+	test_gl([&]{ glBindVertexArray(drawing_vertex_array_); });
+	test_gl([&]{ glBindBuffer(GL_ARRAY_BUFFER, drawing_array_buffer_); });
+
+	const GLint position_attribute = pixel_shader_.get_attrib_location("position");
+	test_gl([&]{ glEnableVertexAttribArray(GLuint(position_attribute)); });
+
+	test_gl([&]{
+		glVertexAttribPointer(
+			(GLuint)position_attribute,
+			2,
+			GL_FLOAT,
+			GL_FALSE,
+			2 * sizeof(GLfloat),
+			(void *)0
+		);
+	});
+
+	colour_uniform_ = pixel_shader_.get_uniform_location("colour");
+
+	// Store positions.
+	const float buffer[4*2] = {
+		x,			y,
+		x,			y + height,
+		x + width,	y,
+		x + width,	y + height
+	};
+
+	// Upload buffer.
+	test_gl([&]{ glBindBuffer(GL_ARRAY_BUFFER, drawing_array_buffer_); });
+	test_gl([&]{ glBufferData(GL_ARRAY_BUFFER, sizeof(buffer), buffer, GL_STATIC_DRAW); });
+}
+
+void Rectangle::draw(const float red, const float green, const float blue) {
+	pixel_shader_.bind();
+	test_gl([&]{ glUniform4f(colour_uniform_, red, green, blue, 1.0); });
+
+	test_gl([&]{ glBindVertexArray(drawing_vertex_array_); });
+	test_gl([&]{ glDrawArrays(GL_TRIANGLE_STRIP, 0, 4); });
+}