1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
|
#include <stdlib.h>
#include <gtk/gtk.h>
#include <gtk/gtkgl.h>
#include <GL/gl.h>
#include <GL/glu.h>
#include <gdk/x11/gdkglx.h> // X11 specific
gboolean gl_area_on_draw (GtkObject* area, GdkEventExpose* event, gpointer data) {
GdkGLDrawable* drawable = gtk_widget_get_gl_drawable (GTK_WIDGET (area));
GdkGLContext* context = gtk_widget_get_gl_context (GTK_WIDGET (area));
gboolean status = gdk_gl_drawable_gl_begin (drawable, context);
if (status == FALSE) {
return FALSE;
}
GtkAllocation allocation;
gtk_widget_get_allocation (GTK_WIDGET (area), &allocation);
GLdouble viewport_width = (GLdouble) allocation.width;
GLdouble viewport_height = (GLdouble) allocation.height;
// Z negative forward oriented.
GLdouble aspect = viewport_width / viewport_height;
GLdouble fovy = 35.0; // The one which looks to most natural.
GLdouble zNear = 2.0; // Enough for a moderately sized sample model.
GLdouble zFar = -2.0; // Idem.
// Z positive forward oriented.
GLdouble projection_dx = 0.0;
GLdouble projection_dy = 0.0;
GLdouble projection_dz = -3.0;
// Reset picture.
glViewport (0, 0, (GLint) viewport_width, (GLint) viewport_height);
glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
// Model defined in default coordinates.
glMatrixMode (GL_MODELVIEW);
glLoadIdentity ();
// Projection using perspective and a few units backward.
glMatrixMode (GL_PROJECTION);
glLoadIdentity ();
gluPerspective (fovy, aspect, zNear, zFar);
glTranslated (projection_dx, projection_dy, projection_dz);
// Use the line below instead of the two above, for non perspective view.
// glOrtho (-aspect, +aspect, -1.0, +1.0, zNear, zFar);
// Draw a 1x1 square center on origin and on the x*y plan.
// x*y*z, Z negative forward oriented.
glBegin (GL_QUADS);
glVertex3d ( 0.5, -0.5, 0.0);
glVertex3d ( 0.5, 0.5, 0.0);
glVertex3d (-0.5, 0.5, 0.0);
glVertex3d (-0.5, -0.5, 0.0);
glEnd ();
gdk_gl_drawable_swap_buffers (drawable);
gdk_gl_drawable_gl_end (drawable);
return TRUE; // Do not propagate the event.
}
int main(int argc, char *argv[]) {
GtkWidget* main_win;
GtkVBox* main_box;
GtkDrawingArea* gl_area;
GdkGLConfig* gl_config;
GdkGLContext* gl_context;
GLXContext glx_context; // X11 specific
gboolean res;
gtk_init(&argc, &argv);
if (gdk_gl_init_check(&argc, &argv) == FALSE ) {
fputs ("Failed to initialize GDKGLExt.\n", stderr);
return EXIT_FAILURE;
}
main_win = gtk_window_new(GTK_WINDOW_TOPLEVEL);
gtk_window_set_default_size(GTK_WINDOW(main_win), 400, 300);
gtk_window_set_title(GTK_WINDOW(main_win), "GTK OpenCL Proof of Concept");
gtk_signal_connect(GTK_OBJECT(main_win), "destroy", G_CALLBACK(gtk_main_quit), NULL);
main_box = GTK_VBOX(gtk_vbox_new(FALSE, 0));
gtk_container_add(GTK_CONTAINER(main_win), GTK_WIDGET(main_box));
gl_area = GTK_DRAWING_AREA(gtk_drawing_area_new());
gl_config = gdk_gl_config_new_by_mode(GDK_GL_MODE_RGBA | GDK_GL_MODE_DOUBLE | GDK_GL_MODE_DEPTH);
res = gtk_widget_set_gl_capability(GTK_WIDGET(gl_area), gl_config,
/* GdkGLContext *share_list */ NULL,
/* gboolean direct */ TRUE,
/* int render_type */ GDK_GL_RGBA_TYPE);
if ( !res ) {
fputs ("Failed to set_gl_capability(gl_area)\n", stderr);
return EXIT_FAILURE;
}
gtk_signal_connect(GTK_OBJECT(gl_area), "expose-event", GTK_SIGNAL_FUNC(gl_area_on_draw), NULL);
gtk_box_pack_start(GTK_BOX(main_box), GTK_WIDGET(gl_area), TRUE, TRUE, 0);
gtk_widget_show_all(main_win);
/* gl_area needs to be realized to do that (so, it is after gtk_widget_show_all(main_win) )*/
gl_context=gtk_widget_get_gl_context(GTK_WIDGET(gl_area));
if ( !gl_context) {
fputs ("Failed to get_gl_context(gl_area)\n", stderr);
return EXIT_FAILURE;
}
/* BEGIN : X11 specific */
glx_context=gdk_x11_gl_context_get_glxcontext(gl_context);
if ( !glx_context) {
fputs ("Failed to gdk_x11_gl_context_get_glxcontext(gl_context)\n", stderr);
return EXIT_FAILURE;
}
printf("glx_context==%p\n", (void *)glx_context);
/* END : X11 specific */
gtk_main();
return EXIT_SUCCESS;
}
|
