Artifact 84c839fe611422315f7326f40dcdc6b0718013bf:

• File operator/screen-rgba-rgba.crimp — part of check-in [8942f8463c] at 2010-07-15 22:05:09 on branch ak-experimental — 7 seven new binary operators (max, min, multiply, screen, add, subtract, difference) Added to C level (rgba/rgba only so far), Tcl level, and demos. No documentation yet. (user: andreask size: 579) [more...]

screen_rgba_rgba
Tcl_Obj* imageAObj
Tcl_Obj* imageBObj

/*
 * Pixel- and channel-wise 1-(1-A)*(1-B) combination of two images. The images
 * have to have equal dimensions. This could be done at Tcl level using a
 * combination of 'multiply' and 'invert'. Doing it in C on the other hand
 * avoids the three temporary images of that implementation.
 */

#define BINOP(a,b) (255 - (((255-(a))*(255-(b)))/255))
#include "binop_rgba_rgba.c"
#undef BINOP

/* vim: set sts=4 sw=4 tw=80 et ft=c: */
/*
 * Local Variables:
 * mode: c
 * c-basic-offset: 4
 * fill-column: 78
 * End:
 */