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[STR New]
Link: http://www.fltk.org/str.php?L2606
Version: 1.3-current
If using a negative line data size to flip a image alpha blending on X11
didn't use the line data size and this would cause reading outside of the
allocated data. I have attached a patch and the complete file that fixes
this problem.
Link: http://www.fltk.org/str.php?L2606
Version: 1.3-current
Index: src/Fl_Image.cxx
===================================================================
--- src/Fl_Image.cxx (revision 8592)
+++ src/Fl_Image.cxx (working copy)
@@ -378,13 +378,18 @@
#if !defined(WIN32) && !defined(__APPLE_QUARTZ__)
// Composite an image with alpha on systems that don't have accelerated
// alpha compositing...
-static void alpha_blend(Fl_RGB_Image *img, int X, int Y, int W, int H, int cx,
int cy) {
+static void alpha_blend(Fl_RGB_Image *img, int X, int Y, int W, int H, int cx,
int cy, int ld) {
uchar *srcptr = (uchar*)img->array + img->d() * (img->w() * cy + cx);
+ if(ld != 0)
+ srcptr = (uchar*)img->array + ld*cy + cx*img->d();
int srcskip = img->d() * (img->w() - W);
uchar *dst = new uchar[W * H * 3];
uchar *dstptr = dst;
+ if(ld < 0)
+ ld *= 2;
+
fl_read_image(dst, X, Y, W, H, 0);
uchar srcr, srcg, srcb, srca;
@@ -393,7 +398,7 @@
if (img->d() == 2) {
// Composite grayscale + alpha over RGB...
// Composite RGBA over RGB...
- for (int y = H; y > 0; y--, srcptr+=srcskip)
+ for (int y = H; y > 0; y--, srcptr+=srcskip) {
for (int x = W; x > 0; x--) {
srcg = *srcptr++;
srca = *srcptr++;
@@ -407,9 +412,11 @@
*dstptr++ = (srcg * srca + dstg * dsta) >> 8;
*dstptr++ = (srcg * srca + dstb * dsta) >> 8;
}
+ srcptr += ld;
+ }
} else {
// Composite RGBA over RGB...
- for (int y = H; y > 0; y--, srcptr+=srcskip)
+ for (int y = H; y > 0; y--, srcptr+=srcskip) {
for (int x = W; x > 0; x--) {
srcr = *srcptr++;
srcg = *srcptr++;
@@ -425,6 +432,8 @@
*dstptr++ = (srcg * srca + dstg * dsta) >> 8;
*dstptr++ = (srcb * srca + dstb * dsta) >> 8;
}
+ srcptr += ld;
+ }
}
fl_draw_image(dst, X, Y, W, H, 3, 0);
@@ -569,7 +578,7 @@
}
} else {
// Composite image with alpha manually each time...
- alpha_blend(img, X, Y, W, H, cx, cy);
+ alpha_blend(img, X, Y, W, H, cx, cy, img->ld());
}
}
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