Pileus Git - grits/blob - src/examples/tex.c

   1 #include <gtk/gtk.h>
   2 #include <gtk/gtkgl.h>
   3 #include <gdk/gdkkeysyms.h>
   4 #include <GL/gl.h>
   5 #include <GL/glu.h>
   6
   7 guint tex, texl, texr;
   8
   9 gboolean on_key_press(GtkWidget *widget, GdkEventKey *event, gpointer _)
  10 {
  11         if (event->keyval == GDK_q)
  12                 gtk_main_quit();
  13         return FALSE;
  14 }
  15
  16 gboolean on_expose(GtkWidget *drawing, GdkEventExpose *event, gpointer _)
  17 {
  18         glClearColor(0.5, 0.5, 1.0, 1.0);
  19         glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
  20
  21         glMatrixMode(GL_PROJECTION);
  22         glLoadIdentity();
  23         glOrtho(-1,1, -1,1, 10,-10);
  24         glMatrixMode(GL_MODELVIEW);
  25         glLoadIdentity();
  26         glTranslatef(0, 0, -5);
  27
  28         glEnable(GL_COLOR_MATERIAL);
  29         glDisable(GL_TEXTURE_2D);
  30         glColor3f(1.0, 1.0, 1.0);
  31         glBegin(GL_QUADS);
  32         glVertex3f(-0.25, -0.75, 0.0);
  33         glVertex3f(-0.25,  0.75, 0.0);
  34         glVertex3f( 0.25,  0.75, 0.0);
  35         glVertex3f( 0.25, -0.75, 0.0);
  36         glEnd();
  37
  38         /* Textures */
  39         glDisable(GL_COLOR_MATERIAL);
  40         glEnable(GL_TEXTURE_2D);
  41         glEnable(GL_BLEND);
  42
  43         gdouble y = 0.875;
  44
  45         /* Left */
  46         glBlendFunc(GL_ONE, GL_ZERO);
  47         glBindTexture(GL_TEXTURE_2D, texl);
  48         glBegin(GL_QUADS);
  49         glTexCoord2f(0.0, y); glVertex3f(-0.75,  0.0, 0.0);
  50         glTexCoord2f(0.0, 1.0); glVertex3f(-0.75,  0.5, 0.0);
  51         glTexCoord2f(2.0, 1.0); glVertex3f( 0.75,  0.5, 0.0);
  52         glTexCoord2f(2.0, y); glVertex3f( 0.75,  0.0, 0.0);
  53         glEnd();
  54
  55         /* Right */
  56         glBlendFunc(GL_ONE, GL_ONE);
  57         glBindTexture(GL_TEXTURE_2D, texr);
  58         glBegin(GL_QUADS);
  59         glTexCoord2f(-1.0, y); glVertex3f(-0.75, 0.0, 0.0);
  60         glTexCoord2f(-1.0, 1.0); glVertex3f(-0.75, 0.5, 0.0);
  61         glTexCoord2f( 1.0, 1.0); glVertex3f( 0.75, 0.5, 0.0);
  62         glTexCoord2f( 1.0, y); glVertex3f( 0.75, 0.0, 0.0);
  63         glEnd();
  64
  65         /* Bottom */
  66         glBlendFunc(GL_ONE, GL_ZERO);
  67         glBindTexture(GL_TEXTURE_2D, tex);
  68         glBegin(GL_QUADS);
  69         glTexCoord2f(0.0, 0.0); glVertex3f(-0.75, -0.5, 0.0);
  70         glTexCoord2f(0.0, 1.0-y); glVertex3f(-0.75, -0.0, 0.0);
  71         glTexCoord2f(1.0, 1.0-y); glVertex3f( 0.75, -0.0, 0.0);
  72         glTexCoord2f(1.0, 0.0); glVertex3f( 0.75, -0.5, 0.0);
  73         glEnd();
  74
  75
  76         /* Flush */
  77         GdkGLDrawable *gldrawable = gdk_gl_drawable_get_current();
  78         if (gdk_gl_drawable_is_double_buffered(gldrawable))
  79                 gdk_gl_drawable_swap_buffers(gldrawable);
  80         else
  81                 glFlush();
  82         return FALSE;
  83 }
  84 gboolean on_configure(GtkWidget *drawing, GdkEventConfigure *event, gpointer _)
  85 {
  86         glViewport(0, 0,
  87                 drawing->allocation.width,
  88                 drawing->allocation.height);
  89         return FALSE;
  90 }
  91
  92 guint load_tex(gchar *filename)
  93 {
  94         GdkPixbuf *pixbuf = gdk_pixbuf_new_from_file(filename, NULL);
  95         guchar    *pixels = gdk_pixbuf_get_pixels(pixbuf);
  96         int        width  = gdk_pixbuf_get_width(pixbuf);
  97         int        height = gdk_pixbuf_get_height(pixbuf);
  98         int        alpha  = gdk_pixbuf_get_has_alpha(pixbuf);
  99         guint      tex;
 100         glGenTextures(1, &tex);
 101         glBindTexture(GL_TEXTURE_2D, tex);
 102         glTexImage2D(GL_TEXTURE_2D, 0, 4, width, height, 0,
 103                         (alpha ? GL_RGBA : GL_RGB), GL_UNSIGNED_BYTE, pixels);
 104         glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
 105         glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
 106
 107         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_BORDER);
 108         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_BORDER);
 109         g_object_unref(pixbuf);
 110         return tex;
 111 }
 112
 113 int main(int argc, char **argv)
 114 {
 115         gtk_init(&argc, &argv);
 116
 117         GtkWidget   *window   = gtk_window_new(GTK_WINDOW_TOPLEVEL);
 118         GtkWidget   *drawing  = gtk_drawing_area_new();
 119         GdkGLConfig *glconfig = gdk_gl_config_new_by_mode((GdkGLConfigMode)(
 120                         GDK_GL_MODE_RGBA   | GDK_GL_MODE_DEPTH |
 121                         GDK_GL_MODE_DOUBLE | GDK_GL_MODE_ALPHA));
 122         g_signal_connect(window,  "destroy",         G_CALLBACK(gtk_main_quit), NULL);
 123         g_signal_connect(window,  "key-press-event", G_CALLBACK(on_key_press),  NULL);
 124         g_signal_connect(drawing, "expose-event",    G_CALLBACK(on_expose),     NULL);
 125         g_signal_connect(drawing, "configure-event", G_CALLBACK(on_configure),  NULL);
 126         gtk_widget_set_gl_capability(drawing, glconfig, NULL, TRUE, GDK_GL_RGBA_TYPE);
 127         gtk_container_add(GTK_CONTAINER(window), drawing);
 128         gtk_widget_show_all(window);
 129
 130         /* OpenGL setup */
 131         GdkGLContext  *glcontext  = gtk_widget_get_gl_context(GTK_WIDGET(drawing));
 132         GdkGLDrawable *gldrawable = gtk_widget_get_gl_drawable(GTK_WIDGET(drawing));
 133         gdk_gl_drawable_gl_begin(gldrawable, glcontext);
 134
 135         /* Load texture */
 136         texl = load_tex("tex_png/texls.png");
 137         texr = load_tex("tex_png/texrs.png");
 138         tex  = load_tex("tex_png/tex.png");
 139
 140         gtk_main();
 141
 142         gdk_gl_drawable_gl_end(gldrawable);
 143 }