1 /*
2  * This file is part of gtkD.
3  * 
4  * dui is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU Lesser General Public License as published by
6  * the Free Software Foundation; either version 3 of the License, or
7  * (at your option) any later version.
8  * 
9  * dui is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU Lesser General Public License for more details.
13  * 
14  * You should have received a copy of the GNU Lesser General Public License
15  * along with dui; if not, write to the Free Software
16  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110, USA
17  */
18 
19 module simpleGL.SimpleGL;
20 
21 private import gdk.Event;
22 private import gtk.DrawingArea;
23 private import gtk.Main;
24 private import gtk.MainWindow;
25 private import gtk.Widget;
26 private import glgdk.GLConfig;
27 private import glgdk.GLContext;
28 private import glgdk.GLdInit;
29 private import glgdk.GLWindow;
30 private import glgtk.GLCapability;
31 private import gtkglc.glgdktypes;
32 
33 private import gtkglc.gl;
34 private import gtkglc.glu;
35 
36 /**
37  * This is a Simple class extending the DrawingArea widget.
38  * A really simple Demo illustrating OpenGL with GtkD
39  * It uses the GLCapability mixin to add the GL capabilities to the widget.
40  * This example is provided under the terms of the GPL License.
41  * Note the initialization of the GLCapabilities on the constructor.
42  * 
43  * @author pac@tuxfamily.org
44  */
45 class SimpleGL : DrawingArea
46 {
47 
48 	GLfloat width;
49 	GLfloat height;
50 	
51 	/** need to include the mixin to add GL capabilities to this widget */
52 	mixin GLCapability;
53 
54 	/**
55 	 * Construct a simple DrawingArea and sets the GLCapabilities
56 	 */
57 	this()
58 	{
59 		super(300, 300);
60 		setGlCapability();	// set the GL capabilities for this widget
61 	}
62 
63 	/**
64 	 * put any gl initializations here
65 	 * returns true to consume the event
66 	 */
67 	void initGL()
68 	{
69 		resizeGL(null);
70 	}
71 	
72 	/**
73 	 * This method is called every time the window must be paint or repaint
74 	 * This is where you put the OpenGL call to draw something.
75 	 * This method call be called directly by the application without an event object
76 	 * to force redrawing of the scene.
77 	 * returns true to consume the event
78 	 */
79 	bool drawGL()
80 	{
81 		glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
82 		glLoadIdentity ();
83 
84 		gluLookAt(0, 0, 10, 0, 0, 0, 0, 1,0); //Set the camera position
85 
86 		//Just Draw a tri-colored triangle
87 		glBegin(GL_TRIANGLES);
88 		glColor3f(1.0f,0.0f,0.0f);
89 		glVertex3f( 0.0f, 1.0f, 0.0f);
90 		glColor3f(0.0f,1.0f,0.0f);
91 		glVertex3f(-1.0f,-1.0f, 0.0f);
92 		glColor3f(0.0f,0.0f,1.0f);
93 		glVertex3f( 1.0f,-1.0f, 0.0f);
94 		glEnd();
95 			
96 		return true;
97 	}
98 
99 	/**
100 	 * This method is called when the window is resized
101 	 * returns true to consume the event
102 	 */
103 	bool resizeGL(Event event = null)
104 	{
105 		GLfloat w;
106 		GLfloat h;
107 		
108 		if ( event is null || event.type != GdkEventType.CONFIGURE )
109 		{
110 			w = getWidth();
111 			h = getHeight();
112 		}
113 		else
114 		{
115 			w = event.configure.width;
116 			h = event.configure.height;
117 		}
118 		
119 		width = w;
120 		height = h;
121 		
122 		glViewport (0, 0, cast(int)w, cast(int)h); //Adjust the viewport according to new window dimensions 
123 
124 		/*
125 		 * Update the projection Matrix accoding to the new dimension
126 		 * and reset the OpenGL state to MODELVIEW
127 		 */
128 		glMatrixMode (GL_PROJECTION);
129 		glLoadIdentity ();
130 		gluPerspective(20, w/h, 0.1, 10);
131 		glMatrixMode (GL_MODELVIEW);
132 
133 		return true;
134 	}
135 }
136  
137 void main(string[] args)
138 {
139 	Main.init(args);
140 
141 	GLdInit.init(args);
142 	
143 	SimpleGL simpleGL = new SimpleGL();
144 	MainWindow window = new MainWindow("Simplest OpenGL Example");
145 	window.add(simpleGL);
146 	window.showAll();
147 		
148 	Main.run();
149 }