[cairo] Newbie - simple program doesn't work

[Behdad Esfahbod]

On Mon, 2006-07-10 at 05:57 -0400, Fabien Costantini wrote:
> 
> This is probably because cairo_fill() doesn't know what to fill in
> your code.
> you should add before your cairo_fill() call, something like :
>     cairo_rectangle(cr,0,0,WIDTH,HEIGHT);
> so that cairo_fill() knows that the closed path on which to apply the
> fill is your whole surface.

Or just use cairo_paint() instead.

> Fabien
> 
> ----- Message d'origine ----
> De : Baptiste Gaillard <b_gaillard at hotmail.com>
> À : cairo at cairographics.org
> Envoyé le : Lundi, 10 Juillet 2006, 11h34mn 47s
> Objet : [cairo] Newbie - simple program doesn't work
> 
> Hello, I'm begining with cairo with a very simple program that doesn't
> work, but I don't understand why !!!
> Here is the code:
>  
> #include <cairo-win32.h>
> 
> #define WIDTH 10000
> 
> #define HEIGHT 10000
> 
> void display_status(cairo_status_t status) {
> 
> switch(status) {
> 
> case CAIRO_STATUS_SUCCESS:
> 
> cout << "CAIRO_STATUS_SUCCESS" << endl;
> 
> break;
> 
> case CAIRO_STATUS_NULL_POINTER:
> 
> cout << "CAIRO_STATUS_NULL_POINTER" << endl;
> 
> break; 
> 
> case CAIRO_STATUS_NO_MEMORY:
> 
> cout << "CAIRO_STATUS_NO_MEMORY" << endl;
> 
> break; 
> 
> case CAIRO_STATUS_READ_ERROR:
> 
> cout << "CAIRO_STATUS_READ_ERROR" << endl;
> 
> break;
> 
> case CAIRO_STATUS_INVALID_CONTENT:
> 
> cout << "CAIRO_STATUS_INVALID_CONTENT" << endl;
> 
> break;
> 
> case CAIRO_STATUS_INVALID_FORMAT:
> 
> cout << "CAIRO_STATUS_INVALID_FORMAT" << endl;
> 
> break;
> 
> case CAIRO_STATUS_INVALID_VISUAL:
> 
> cout << "CAIRO_STATUS_INVALID_VISUAL" << endl;
> 
> break;
> 
> }
> 
> }
> 
> int main(int argc, char** argv) {
> 
> cairo_surface_t *surface;
> 
> cairo_t *cr;
> 
> surface = cairo_image_surface_create (CAIRO_FORMAT_RGB24, WIDTH,
> HEIGHT); 
> 
> display_status(cairo_surface_status (surface));
> 
> cr = cairo_create (surface);
> 
> display_status(cairo_surface_status (surface)); 
> 
> cairo_set_source_rgb(cr, 1,1,1);
> 
> cairo_fill(cr);
> 
> display_status(cairo_surface_status (surface));
> 
> cairo_surface_write_to_png (surface, "test.png"); 
> 
> display_status(cairo_surface_status (surface));
> 
> cairo_destroy (cr);
> 
> cairo_surface_destroy (surface);
> 
> return 0;
> 
> }
> 
>  
> 
> The program create a png image, but it's filled in black whereas it
> should be white. I tried to draw paths and other forms but it seems
> that the image buffer isn't 
> 
> modified. I'm working on Windows with DevC++ and use the cairo library
> provided with the GTK+ package for windows as indicated on the Cairo
> web site. 
> 
> So, do you know why this code doesn't work ?
> 
> Thanks
> 
>  
> 
> PS: sorry for my English, I'm french :-) 
> 
> 
> _______________________________________________
> cairo mailing list
> cairo at cairographics.org
> http://cairographics.org/cgi-bin/mailman/listinfo/cairo
> 
> 
> 
> 
> _______________________________________________
> cairo mailing list
> cairo at cairographics.org
> http://cairographics.org/cgi-bin/mailman/listinfo/cairo
-- 
behdad
http://behdad.org/

"Commandment Three says Do Not Kill, Amendment Two says Blood Will Spill"
        -- Dan Bern, "New American Language"