Heya,
I want to write a program that startup takes a screenshot of what ever is on the screen to use as a background within the program.
I've already found the fantastic code to get a bitmap from the clipboard, so I thought that using 'simulate_key(KEY_PRTSCR);' would copy it to the clipboard, but Windows doesn't accept the key press (it ignores it) I guess that simulate_key simply sets that keys flag to true, but what I'd like to find out is; is there another way to capture the screen image?
I've included the code below.
Cheers
Phoenix
| 1 | #include <allegro.h> |
| 2 | #include <winalleg.h> |
| 3 | |
| 4 | BITMAP* getBitmapFromClipboard() { |
| 5 | BITMAP *result = NULL; |
| 6 | |
| 7 | if (!IsClipboardFormatAvailable(CF_BITMAP)) { |
| 8 | return NULL; |
| 9 | } |
| 10 | |
| 11 | if (OpenClipboard(win_get_window())) { |
| 12 | HBITMAP hbmp; |
| 13 | |
| 14 | hbmp = GetClipboardData(CF_BITMAP); |
| 15 | if (hbmp != NULL) { |
| 16 | result = convert_hbitmap_to_bitmap(hbmp); |
| 17 | } |
| 18 | CloseClipboard(); |
| 19 | } |
| 20 | return result; |
| 21 | } |
| 22 | |
| 23 | |
| 24 | |
| 25 | int main(int argc, char** argv) { |
| 26 | BITMAP *bmp; |
| 27 | |
| 28 | allegro_init(); |
| 29 | install_timer(); |
| 30 | install_mouse(); |
| 31 | install_keyboard(); |
| 32 | simulate_keypress(KEY_PRTSCR); |
| 33 | rest(1000); |
| 34 | set_color_depth(32); |
| 35 | set_gfx_mode(1,1024,768, 0, 0); |
| 36 | |
| 37 | bmp = getBitmapFromClipboard(); |
| 38 | |
| 39 | if (bmp) { |
| 40 | // Draw a rectangle on it just to test!! |
| 41 | rectfill(bmp,100,100,200,200,makecol(255,0,255)); |
| 42 | blit(bmp, screen, 0, 0, 0, 0, bmp->w, bmp->h); |
| 43 | } |
| 44 | clear_keybuf(); |
| 45 | readkey(); |
| 46 | |
| 47 | destroy_bitmap(bmp); |
| 48 | |
| 49 | allegro_exit(); |
| 50 | } |
| 51 | END_OF_MAIN() |
]]>
Allegro does not provide a way to grab an image of the desktop. Each operating system has a different means of accessing the desktop image. For Windows, you might want to look at the sourcecode for ChromaPlas to see how it's done on Windows.
AE.
]]>Basically, you would use GetDC(NULL) to get a HDC for the entire screen.
Then, you can use Windows specific Allegro functions, described here in the manual. Specifically, you want blit_from_hdc.
If you want to use that, be sure to include winalleg.h.
]]>Grabbing a picture of the desktop is no longer possible for screen savers as of XP.
]]>But you can grab a screenshot in a screen saver, right?
]]>Grabbing a picture of the desktop is no longer possible for screen savers as of XP.
Is that only as of XP SP2? I could have sworn I've gotten ChromaPlas in desptop-image mode to work on an XP-based machine.
Even if it were true, it would be a pity, as it would prevent the many screensavers that maipulate the desktop image from working.
AE.
]]>