avoid a possible sign-extension for offsets/sizes in SGI

[imager.git] / image.c

diff --git a/image.c b/image.c
index 56057e877b436f5fd1ba35fe4549dec619edcfcf..bd634ee1480b43ff15664653043a052a456c9661 100644 (file)
--- a/image.c
+++ b/image.c
@@ -44,8 +44,11 @@ im_context_t (*im_get_context)(void) = NULL;
 void i_linker_bug_fake(void) { ceil(1); }
 
 /*
-=item i_img_alloc()
+=item im_img_alloc(aIMCTX)
+X<im_img_alloc API>X<i_img_alloc API>
 =category Image Implementation
+=synopsis i_img *im = im_img_alloc(aIMCTX);
+=synopsis i_img *im = i_img_alloc();
 
 Allocates a new i_img structure.
 
@@ -79,13 +82,15 @@ im_img_alloc(pIMCTX) {
 }
 
 /*
-=item i_img_init(C<img>)
+=item im_img_init(aIMCTX, image)
+X<im_img_init API>X<i_img_init API>
 =category Image Implementation
+=synopsis im_img_init(aIMCTX, im);
+=synopsis i_img_init(im);
 
 Imager internal initialization of images.
 
-Currently this does very little, in the future it may be used to
-support threads, or color profiles.
+See L</im_img_alloc(aIMCTX)> for more information.
 
 =cut
 */
@@ -313,21 +318,15 @@ void
 i_img_info(i_img *im, i_img_dim *info) {
   dIMCTXim(im);
   im_log((aIMCTX,1,"i_img_info(im %p)\n",im));
-  if (im != NULL) {
-    im_log((aIMCTX,1,"i_img_info: xsize=%" i_DF " ysize=%" i_DF " channels=%d "
-           "mask=%ud\n",
-           i_DFc(im->xsize), i_DFc(im->ysize), im->channels,im->ch_mask));
-    im_log((aIMCTX,1,"i_img_info: idata=%p\n",im->idata));
-    info[0] = im->xsize;
-    info[1] = im->ysize;
-    info[2] = im->channels;
-    info[3] = im->ch_mask;
-  } else {
-    info[0] = 0;
-    info[1] = 0;
-    info[2] = 0;
-    info[3] = 0;
-  }
+
+  im_log((aIMCTX,1,"i_img_info: xsize=%" i_DF " ysize=%" i_DF " channels=%d "
+         "mask=%ud\n",
+         i_DFc(im->xsize), i_DFc(im->ysize), im->channels,im->ch_mask));
+  im_log((aIMCTX,1,"i_img_info: idata=%p\n",im->idata));
+  info[0] = im->xsize;
+  info[1] = im->ysize;
+  info[2] = im->channels;
+  info[3] = im->ch_mask;
 }
 
 /*
@@ -399,6 +398,85 @@ i_img_get_height(i_img *im) {
   return im->ysize;
 }
 
+/*
+=item i_img_color_model(im)
+=category Image Information
+=synopsis i_color_model_t cm = i_img_color_model(im);
+
+Returns the color model for the image.
+
+A future version of Imager will allow for images with extra channels
+beyond gray/rgb and alpha.
+
+=cut
+*/
+i_color_model_t
+i_img_color_model(i_img *im) {
+  return (i_color_model_t)im->channels;
+}
+
+/*
+=item i_img_alpha_channel(im, &channel)
+=category Image Information
+=synopsis int alpha_channel;
+=synopsis int has_alpha = i_img_alpha_channel(im, &alpha_channel);
+
+Work out the alpha channel for an image.
+
+If the image has an alpha channel, sets C<*channel> to the alpha
+channel index and returns non-zero.
+
+If the image has no alpha channel, returns zero and C<*channel> is not
+modified.
+
+C<channel> may be C<NULL>.
+
+=cut
+*/
+
+int
+i_img_alpha_channel(i_img *im, int *channel) {
+  i_color_model_t model = i_img_color_model(im);
+  switch (model) {
+  case icm_gray_alpha:
+  case icm_rgb_alpha:
+    if (channel) *channel = (int)model - 1;
+    return 1;
+
+  default:
+    return 0;
+  }
+}
+
+/*
+=item i_img_color_channels(im)
+=category Image Information
+=synopsis int color_channels = i_img_color_channels(im);
+
+Returns the number of color channels in the image.  For now this is
+always 1 (for grayscale) or 3 (for RGB) but may be 0 in some special
+cases in a future release of Imager.
+
+=cut
+*/
+
+int
+i_img_color_channels(i_img *im) {
+  i_color_model_t model = i_img_color_model(im);
+  switch (model) {
+  case icm_gray_alpha:
+  case icm_rgb_alpha:
+    return (int)model - 1;
+
+  case icm_gray:
+  case icm_rgb:
+    return (int)model;
+
+  default:
+    return 0;
+  }
+}
+
 /*
 =item i_copyto_trans(C<im>, C<src>, C<x1>, C<y1>, C<x2>, C<y2>, C<tx>, C<ty>, C<trans>)
 
@@ -1044,7 +1122,7 @@ i_haar(i_img *im) {
   i_img_dim mx,my;
   i_img_dim fx,fy;
   i_img_dim x,y;
-  int ch,c;
+  int ch;
   i_img *new_img,*new_img2;
   i_color val1,val2,dval1,dval2;
   dIMCTXim(im);
@@ -1060,7 +1138,6 @@ i_haar(i_img *im) {
   new_img=i_img_empty_ch(NULL,fx*2,fy*2,im->channels);
   new_img2=i_img_empty_ch(NULL,fx*2,fy*2,im->channels);
 
-  c=0; 
   for(y=0;y<my;y++) for(x=0;x<fx;x++) {
     i_gpix(im,x*2,y,&val1);
     i_gpix(im,x*2+1,y,&val2);
@@ -1127,7 +1204,8 @@ i_count_colors(i_img *im,int maxc) {
       for(x = 0; x < samp_cnt; ) {
           colorcnt += octt_add(ct, samp[x], samp[x+1], samp[x+2]);
           x += 3;
-          if (colorcnt > maxc) { 
+          if (colorcnt > maxc) {
+             myfree(samp);
               octt_delete(ct); 
               return -1; 
           }
@@ -1218,7 +1296,8 @@ i_get_anonymous_color_histo(i_img *im, unsigned int **col_usage, int maxc) {
       colorcnt += octt_add(ct, samp[x], samp[x+1], samp[x+2]);
       x += 3;
       if (colorcnt > maxc) { 
-       octt_delete(ct); 
+       octt_delete(ct);
+       myfree(samp);
        return -1; 
       }
     }
@@ -1631,6 +1710,9 @@ i_test_format_probe(io_glue *data, int length) {
     /* JPEG 2000 
        This might match a little loosely */
     FORMAT_ENTRY("\x00\x00\x00\x0CjP  \x0D\x0A\x87\x0A", "jp2"),
+
+    /* FLIF - Free Lossless Image Format - https://flif.info/spec.html */
+    FORMAT_ENTRY("FLIF", "flif")
   };
   static const struct magic_entry more_formats[] = {
     /* these were originally both listed as ico, but cur files can
@@ -1714,7 +1796,8 @@ i_img_is_monochrome(i_img *im, int *zero_is_white) {
   if (im->type == i_palette_type
       && i_colorcount(im) == 2) {
     i_color colors[2];
-    i_getcolors(im, 0, colors, 2);
+    if (!i_getcolors(im, 0, colors, 2))
+      return 0;
     if (im->channels == 3) {
       if (colors[0].rgb.r == 255 && 
           colors[0].rgb.g == 255 &&