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[STR New] Link: http://www.fltk.org/str.php?L2257 Version: 1.3-current Alex Croy posted this to the fltk.dev list - I'm appending it here so we don't lose it... -------------- the problem is that the current implementation of fl_read_image seems to make a screenshot of the current view (?) instead of accessing the offscreen bitmap. I think I found a solution for this with the routine below. However, there is an additional problem: fl_begin_offscreen and fl_end_offscreen currently do not reset (or clear) the clipping region, which doesn't matter if your make a screenshot. The respective code is actually commented out in Fl_Double_Window. IMHO the calls to fl_push_no_clip and fl_pop_clip should be the last and first calls in l_begin_offscreen and fl_end_offscreen, respectively. Hope that helps somehow ... - Alex -------------------- Here comes the "new" fl_read_image routine: uchar * // O - Pixel buffer or NULL if failed fl_read_image_crutch( uchar *p, // I - Pixel buffer or NULL to allocate int x, // I - Left position int y, // I - Top position int w, // I - Width of area to read int h, // I - Height of area to read int alpha) { // I - Alpha value for image (0 for none) if(fl_window == (void *)0) { // sufficient condition for having an // active offscreen buffer?? CGContextRef src = (CGContextRef)fl_gc; // get bitmap context uchar *base = (uchar *)CGBitmapContextGetData(src); // get data if(!base) return NULL; int sw = CGBitmapContextGetWidth(src); int sh = CGBitmapContextGetHeight(src); // CGImageAlphaInfo bmpalpha = CGBitmapContextGetAlphaInfo(src); int rowBytes = CGBitmapContextGetBytesPerRow(src); int delta = CGBitmapContextGetBitsPerPixel(src)/8; if( (sw - x > w) || (sh - y > h) ) return NULL; // Allocate the image data array as needed... int d = alpha ? 4 : 3; printf("%i %i %i %i %i\n", sw, sh, rowBytes, delta, d); // DEBUG if (!p) p = new uchar[w * h * d]; // Initialize the default colors/alpha in the whole image... memset(p, alpha, w * h * d); // Copy the image from the off-screen buffer to the memory buffer. int idx, idy; // Current X & Y in image uchar *pdst, *psrc; for (idy = 0, pdst = p; idy < h; idy ++) { for (idx = 0, psrc = base + (idy + y) * rowBytes + x; idx < w; idx ++, psrc += delta, pdst += d) { pdst[0] = psrc[0]; // R pdst[1] = psrc[1]; // G pdst[2] = psrc[2]; // B } } return p; } else { // no active offscreen, use "old code" return fl_read_image(p, x, y, w, h, alpha); } } Link: http://www.fltk.org/str.php?L2257 Version: 1.3-current _______________________________________________ fltk-bugs mailing list [email protected] http://lists.easysw.com/mailman/listinfo/fltk-bugs
