gecko/gfx/thebes/cairo-gdk-utils.c

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#include "cairo-gdk-utils.h"

#include <stdlib.h>

#if   HAVE_STDINT_H
#include <stdint.h>
#elif HAVE_INTTYPES_H
#include <inttypes.h>
#elif HAVE_SYS_INT_TYPES_H
#include <sys/int_types.h>
#endif


/* We have three basic strategies available:
   1) 'direct': cr targets a native surface, and other conditions are met: we can
      pass the underlying drawable directly to the callback
   2) 'opaque': the image is opaque: we can create a temporary cairo native surface,
      pass its underlying drawable to the callback, and paint the result
      using cairo
   3) 'default': create a temporary cairo native surface, fill with black, pass its
      underlying drawable to the callback, copy the results to a cairo
      image surface, repeat with a white background, update the on-black
      image alpha values by comparing the two images, then paint the on-black
      image using cairo
   Sure would be nice to have an X extension to do 3 for us on the server...
*/

static cairo_bool_t
_convert_coord_to_short (double coord, short *v)
{
    *v = (short)coord;
    /* XXX allow some tolerance here? */
    return *v == coord;
}

static cairo_bool_t
_convert_coord_to_unsigned_short (double coord, unsigned short *v)
{
    *v = (unsigned short)coord;
    /* XXX allow some tolerance here? */
    return *v == coord;
}


void cairo_draw_with_gdk (cairo_t *cr,
                           cairo_gdk_drawing_callback callback,
                           void * closure,
                           unsigned int width, unsigned int height,
                           cairo_gdk_drawing_opacity_t is_opaque,
                           cairo_gdk_drawing_support_t capabilities,
                           cairo_gdk_drawing_result_t *result)
{
    double device_offset_x, device_offset_y;
    short offset_x = 0, offset_y = 0;
    //cairo_surface_t * target = cairo_get_group_target (cr);
    cairo_surface_t * target = cairo_get_target (cr);
    cairo_matrix_t matrix;

    cairo_surface_get_device_offset (target, &device_offset_x, &device_offset_y);
    cairo_get_matrix (cr, &matrix);

    _convert_coord_to_short (matrix.x0 + device_offset_x, &offset_x);
    _convert_coord_to_short (matrix.y0 + device_offset_y, &offset_y);

    cairo_surface_flush (target);
    callback (closure, target, offset_x, offset_y, NULL, 0);
    cairo_surface_mark_dirty (target);
}