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Diffstat (limited to 'packages/gtk1/examples/gtkgldemo.pp')
| -rw-r--r-- | packages/gtk1/examples/gtkgldemo.pp | 196 |
1 files changed, 196 insertions, 0 deletions
diff --git a/packages/gtk1/examples/gtkgldemo.pp b/packages/gtk1/examples/gtkgldemo.pp new file mode 100644 index 0000000000..60cdc8d129 --- /dev/null +++ b/packages/gtk1/examples/gtkgldemo.pp @@ -0,0 +1,196 @@ +{$MODE DELPHI} + +{$ifdef win32} + {$APPTYPE GUI} +{$endif} + +program gtkgldemo; + +uses glib, gdk, gtk, gtkglarea,gl; + + +function init(widget:PGtkWidget ):gint;cdecl; + +begin + if (gint(True)=gtk_gl_area_make_current(PGtkGLArea(widget))) then + begin + + glViewport(0,0, widget^.allocation.width, widget^.allocation.height); + glMatrixMode(GL_PROJECTION); + glLoadIdentity(); + glOrtho(0,100, 100,0, -1,1); + glMatrixMode(GL_MODELVIEW); + glLoadIdentity(); + + end; + + init:= gint(TRUE); +end; + + + + +(* When widget is exposed its contents are redrawn. *) + +function draw(widget: PGtkWidget; event: PGdkEventExpose): gint; cdecl; + +begin + + (* Draw only last expose. *) + if (event^.count > 0) then + exit(gint(TRUE)); + + (* OpenGL functions can be called only if make_current returns true *) + if (gint(True) = gtk_gl_area_make_current(PGtkGLArea(widget))) then + begin + + glClearColor(0,0,0,1); + glClear(GL_COLOR_BUFFER_BIT); + glColor3f(1,1,1); + glBegin(GL_TRIANGLES); + glVertex2f(10,10); + glVertex2f(10,90); + glVertex2f(90,90); + glEnd(); + + (* Swap backbuffer to front *) + gtk_gl_area_swapbuffers(PGtkGLArea(widget)); + + end; + + exit(gint(TRUE)); +end; + +(* When glarea widget size changes, viewport size is set to match the new size *) + +function reshape(widget:PGtkWidget; event: PGdkEventConfigure):gint; cdecl; +begin + + (* OpenGL functions can be called only if make_current returns true *) + if (gint(True) = gtk_gl_area_make_current(PGtkGLArea(widget))) then + begin + + glViewport(0, 0, widget^.allocation.width, widget^.allocation.height); + + end; + exit( gint(TRUE)); +end; + +var + window,glarea: PGtkWidget; + + (* Attribute list for gtkglarea widget. Specifies a + list of Boolean attributes and enum/integer + attribute/value pairs. The last attribute must be + GDK_GL_NONE. See glXChooseVisual manpage for further + explanation. + *) + + const + attrlist: array [1..11] of LongInt= + ( GDK_GL_RGBA, + GDK_GL_RED_SIZE, 1, + GDK_GL_GREEN_SIZE, 1, + GDK_GL_BLUE_SIZE, 1, + GDK_GL_DEPTH_SIZE,1, + GDK_GL_DOUBLEBUFFER, + GDK_GL_None + ); + +(* int attrlist[] = { + GDK_GL_RGBA, + GDK_GL_RED_SIZE,1, + GDK_GL_GREEN_SIZE,1, + GDK_GL_BLUE_SIZE,1, + GDK_GL_DOUBLEBUFFER, + GDK_GL_NONE + }; +*) + +begin + (* OpenGL functions can be called only if make_current returns true *) +{ if not InitGl then begin + WriteLn('OpenGL is not supported on this system'); + Halt(2); + end;} + + + (* initialize gtk *) + gtk_init(@argc, @argv); + + (* Attribute list for gtkglarea widget. Specifies a + list of Boolean attributes and enum/integer + attribute/value pairs. The last attribute must be + GDK_GL_NONE. See glXChooseVisual manpage for further + explanation. + *) + + + (* vendor dependent version info string *) + { info_str = gdk_gl_get_info(); + g_print(info_str); + g_free(info_str);} + + (* Check if OpenGL is supported. *) + { if (gdk_gl_query() = FALSE) then + begin + g_print("OpenGL not supported\n"); + return 0; + end;} + + + + + (* Create new top level window. *) + window := gtk_window_new( GTK_WINDOW_TOPLEVEL); + gtk_window_set_title(GTK_WINDOW(window), 'OpenGL Output'); + gtk_container_set_border_width(GTK_CONTAINER(window), 10); + + (* Quit form main if got delete event *) + gtk_signal_connect(GTK_OBJECT(window), 'delete_event', + GTK_SIGNAL_FUNC(@gtk_main_quit), NULL); + + + (* You should always delete gtk_gl_area widgets before exit or else + GLX contexts are left undeleted, this may cause problems (=core dump) + in some systems. + Destroy method of objects is not automatically called on exit. + You need to manually enable this feature. Do gtk_quit_add_destroy() + for all your top level windows unless you are certain that they get + destroy signal by other means. + *) + gtk_quit_add_destroy(1, GTK_OBJECT(window)); + + + (* Create new OpenGL widget. *) + glarea := GTK_WIDGET(gtk_gl_area_new(pgint(@attrlist))); + + (* Events for widget must be set before X Window is created *) + gtk_widget_set_events(GTK_WIDGET(glarea), + GDK_EXPOSURE_MASK or + GDK_BUTTON_PRESS_MASK); + + (* Connect signal handlers *) + (* Redraw image when exposed. *) + gtk_signal_connect(GTK_OBJECT(glarea), 'expose_event', GTK_SIGNAL_FUNC(@draw), Nil); + + (* When window is resized viewport needs to be resized also. *) + gtk_signal_connect(GTK_OBJECT(glarea), 'configure_event', GTK_SIGNAL_FUNC(@reshape), Nil); + + (* Do initialization when widget has been realized. *) + gtk_signal_connect(GTK_OBJECT(glarea), 'realize', GTK_SIGNAL_FUNC(@init), Nil); + + (* set minimum size *) + gtk_widget_set_usize(GTK_WIDGET(glarea), 400,400); + + (* put glarea into window and show it all *) + gtk_container_add(GTK_CONTAINER(window),GTK_WIDGET(glarea)); + + + gtk_widget_show(GTK_WIDGET(glarea)); + + gtk_widget_show(GTK_WIDGET(window)); + + gtk_main(); + +end. |