wrong GTK and MacOS TBGRAPixel bytes sequence.

[mohsenti]

Hi,
I develop application with bgrabimap git when using direct access to pixels with bgrabitmap.Data Blue and Red byte are in wrong sequence.
I add -dBGRABITMAP_BGRAPIXEL to package and problem solve.

example source :

Code: Pascal  [Select][+][-]

1. program TransparentGtkWindow;
2.  
3. uses
4.   glib2,
5.   gdk2,
6.   gtk2,
7.   gtk2def,
8.   gtk2proc,
9.   gtk2int,
10.   gdk2pixbuf,
11.   gtk2extra,
12.   cairo,
13.   pango,
14.   pangocairo,
15.   BGRABitmap,
16.   BGRABitmapTypes,
17.   Classes,
18.   SysUtils,
19.   Graphics;
20.  
21. var
22.   Bitmap: TBGRABitmap;
23.  
24.   procedure gdk_window_input_shape_combine_mask(window: PGdkWindow; mask: PGdkBitmap; x, y: GInt); cdecl; external gdklib;
25.   function gtk_widget_get_window(widget: PGtkWidget): PGdkWindow; cdecl; external gtklib;
26.  
27.   procedure Destroy(widget: PGtkWidget; Data: pgpointer); cdecl;
28.   begin
29.     gtk_main_quit;
30.   end;
31.  
32.   procedure SplashExpose(widget: PGtkWidget; event: PGdkEventExpose; userdata: GPointer); cdecl;
33.   var
34.     cr: Pcairo_t;
35.  
36.     surface: Pcairo_surface_t;
37.   begin
38.     cr := gdk_cairo_create(widget^.window);
39.     cairo_set_operator(cr, CAIRO_OPERATOR_SOURCE);
40.     surface := cairo_image_surface_create_for_data(PByte(Bitmap.Data), CAIRO_FORMAT_ARGB32, Bitmap.Width, Bitmap.Height, cairo_format_stride_for_width(CAIRO_FORMAT_ARGB32, Bitmap.Width));
41.     cairo_set_source_surface(cr, surface, 100, 100);
42.     cairo_paint(cr);
43.     cairo_destroy(cr);
44.   end;
45.  
46.   procedure SplashScreenChanged(widget: PGtkWidget; old_screen: PGdkScreen; userdata: GPointer); cdecl;
47.   var
48.     Screen: PGdkScreen;
49.     Colormap: PGdkColormap;
50.   begin
51.     Screen := gtk_widget_get_screen(widget);
52.     Colormap := gdk_screen_get_rgba_colormap(Screen);
53.     gtk_widget_set_colormap(widget, Colormap);
54.   end;
55.  
56.  
57. var
58.   window, fixed_container, button: PGtkWidget;
59.  
60.   procedure clicked(win: PGtkWindow; event: PGdkEventButton; userdata: gpointer); cdecl;
61.   begin
62.     gtk_window_set_decorated(GTK_WINDOW(window), not gtk_window_get_decorated(GTK_WINDOW(window)));
63.   end;
64.  
65. begin
66.  
67.   Bitmap := TBGRABitmap.Create(100, 100);
68.   Bitmap.FillEllipseAntialias(100, 100, 100, 100, BGRA(255, 0, 0, 125));
69.  
70.   gtk_init(@argc, @argv);
71.   window := gtk_window_new(GTK_WINDOW_TOPLEVEL);
72.   gtk_widget_set_size_request(window, 500, 500);
73.   gtk_widget_set_app_paintable(window, True);
74.  
75.   g_signal_connect(G_OBJECT(window), 'destroy',
76.     GTK_SIGNAL_FUNC(@Destroy), NULL);
77.   g_signal_connect(G_OBJECT(window), 'expose-event',
78.     G_CALLBACK(@SplashExpose), NULL);
79.   g_signal_connect(G_OBJECT(window), 'screen-changed',
80.     G_CALLBACK(@SplashScreenChanged), nil);
81.  
82.   gtk_widget_add_events(window, GDK_BUTTON_PRESS_MASK);
83.  
84.   fixed_container := gtk_fixed_new();
85.   gtk_container_add(GTK_CONTAINER(window), fixed_container);
86.   button := gtk_button_new_with_label('button');
87.   g_signal_connect(G_OBJECT(button), 'button-press-event', G_CALLBACK(@clicked), NULL);
88.   gtk_widget_set_size_request(button, 150, 150);
89.   gtk_container_add(GTK_CONTAINER(fixed_container), button);
90.  
91.   SplashScreenChanged(window, nil, nil);
92.  
93.   gtk_window_set_decorated(GTK_WINDOW(window), False);
94.  
95.   gtk_widget_show_all(window);
96.   gtk_main;
97. end.
98.  

[circular]

Yes, you can do that. Or you can call SwapRedBlue before and after using the data depending on the value of TBGRAPixel_RGBAOrder.

Cairo and gtk seem to have a different channel order.