the easy way to get Imager on Win32

[imager.git] / paste.im

diff --git a/paste.im b/paste.im
index 45305df37a9f89af5dadd4a8f5b00dd60bd94b80..a168c46bb14dc86c5676de058e17a9a355691e48 100644 (file)
--- a/paste.im
+++ b/paste.im
@@ -1,22 +1,23 @@
 #include "imager.h"
 
 /*
-=item i_copyto(dest, src, x1, y1, x2, y2, tx, ty)
+=item i_copyto(C<dest>, C<src>, C<x1>, C<y1>, C<x2>, C<y2>, C<tx>, C<ty>)
 
 =category Image
 
-Copies image data from the area (x1,y1)-[x2,y2] in the source image to
-a rectangle the same size with it's top-left corner at (tx,ty) in the
-destination image.
+Copies image data from the area (C<x1>,C<y1>)-[C<x2>,C<y2>] in the
+source image to a rectangle the same size with it's top-left corner at
+(C<tx>,C<ty>) in the destination image.
 
-If x1 > x2 or y1 > y2 then the corresponding co-ordinates are swapped.
+If C<x1> > C<x2> or C<y1> > C<y2> then the corresponding co-ordinates
+are swapped.
 
 =cut
 */
 
 void
 i_copyto(i_img *im, i_img *src, int x1, int y1, int x2, int y2, int tx, int ty) {
-  int x, y, t, ttx, tty;
+  int y, t, ttx, tty;
   
   if (x2<x1) { t=x1; x1=x2; x2=t; }
   if (y2<y1) { t=y1; y1=y2; y2=t; }
@@ -69,7 +70,6 @@ i_adapt_fcolors
 #endif
 (int out_channels, int in_channels, IM_COLOR *colors, 
               size_t count) {
-  int i;
   if (out_channels == in_channels)
     return;
   if (count == 0)
@@ -326,7 +326,125 @@ i_adapt_fcolors_bg
     }
     break;
   }
+}
+
+/*
+=item i_gsamp_bg(im, l, r, y, samples, out_channels, bg)
+
+=item i_gsampf_bg(im, l, r, y, samples, out_channels, bg)
+
+This is similar to i_adapt_colors_bg() except it can only strip an
+alpha channel.  It cannot be used to convert a source RGB image to
+greyscale.
+
+The samples parameter MUST include enough space for all samples of the
+source image.
+
+=cut
+*/
+int
+#ifdef IM_EIGHT_BIT
+i_gsamp_bg
+#else
+i_gsampf_bg
+#endif
+(i_img *im, int l, int r, int y, IM_SAMPLE_T *samples, 
+ int out_channels, IM_COLOR const *bg) {
+  if (out_channels == im->channels)
+    return IM_GSAMP(im, l, r, y, samples, NULL, im->channels);
+  
+  switch (out_channels) {
+  case 1:
+    switch (im->channels) {
+    case 2:
+      {
+       int x;
+       IM_SAMPLE_T *inp = samples, *outp = samples;
+       IM_WORK_T grey_bg = IM_ROUND(color_to_grey(bg));
+       int count;
+
+       count = IM_GSAMP(im, l, r, y, samples, NULL, im->channels);
+       if (!count)
+         return 0;
+       
+       for (x = l; x < r; ++x) {
+         *outp++ = ( inp[0] * inp[1] +
+                     grey_bg * (IM_SAMPLE_MAX - inp[1])) / IM_SAMPLE_MAX;
+         inp += 2;
+       }
+
+       return count;
+      }
+      break;
+
+    default:
+      i_fatal(0, "i_gsamp_bg() can only remove alpha channels");
+      break;
+    }
+    break;
+  case 3:
+    switch (im->channels) {
+    case 1:
+      {
+       int channels[3] = { 0, 0, 0 };
+       return IM_GSAMP(im, l, r, y, samples, channels, out_channels);
+      }
+    case 2:
+      {
+       int x, ch;
+       IM_SAMPLE_T *inp = samples, *outp = samples;
+       int count;
+       int channels[4] = { 0, 0, 0, 1 };
+
+       count = IM_GSAMP(im, l, r, y, samples, channels, im->channels);
+       if (!count)
+         return 0;
+       
+       for (x = l; x < r; ++x) {
+         IM_WORK_T alpha = inp[3];
+         for (ch = 0; ch < 3; ++ch) {
+           *outp++ = ( *inp++ * alpha +
+                       bg->channel[ch] * (IM_SAMPLE_MAX - alpha)) / IM_SAMPLE_MAX;
+         }
+         ++inp;
+       }
+
+       return count;
+      }
+
+    case 4:
+      {
+       int x, ch;
+       IM_SAMPLE_T *inp = samples, *outp = samples;
+       int count;
+
+       count = IM_GSAMP(im, l, r, y, samples, NULL, im->channels);
+       if (!count)
+         return 0;
+       
+       for (x = l; x < r; ++x) {
+         IM_WORK_T alpha = inp[3];
+         for (ch = 0; ch < 3; ++ch) {
+           *outp++ = ( *inp++ * alpha +
+                       bg->channel[ch] * (IM_SAMPLE_MAX - alpha)) / IM_SAMPLE_MAX;
+         }
+         ++inp;
+       }
+
+       return count;
+      }
+      break;
+    default:
+      i_fatal(0, "i_gsamp_bg() can only remove alpha channels");
+      break;
+    }
+    break;
+
+  default:
+    i_fatal(0, "i_gsamp_bg() can only remove alpha channels");
+  }
 
+  return 0;
 }
 
 #/code