add new comparison method rgb_difference that resembles arithmetical difference per...

[imager.git] / rotate.im

diff --git a/rotate.im b/rotate.im
index 8a2a226bae04864824eafc8493eb22f60344cdaa..96981be7ae6030a0f2279ded3849e5d97c0a40e9 100644 (file)
--- a/rotate.im
+++ b/rotate.im
@@ -130,7 +130,6 @@ static i_color interp_i_color(i_color before, i_color after, double pos,
   i_color out;
   int ch;
 
-  pos -= floor(pos);
   if (channels == 1 || channels == 3) {
     for (ch = 0; ch < channels; ++ch)
       out.channel[ch] = ((1-pos) * before.channel[ch] + pos * after.channel[ch]) + 0.5;
@@ -152,6 +151,10 @@ static i_color interp_i_color(i_color before, i_color after, double pos,
        out.channel[ch] = I_LIMIT_8(out_level);
       }
     }
+    else {
+      for (ch = 0; ch < channels-1; ++ch)
+       out.channel[ch] = 0;
+    }
 
     out.channel[channels-1] = total_cover;
   }
@@ -166,7 +169,6 @@ static i_fcolor interp_i_fcolor(i_fcolor before, i_fcolor after, double pos,
   i_fcolor out;
   int ch;
 
-  pos -= floor(pos);
   if (channels == 1 || channels == 3) {
     for (ch = 0; ch < channels; ++ch)
       out.channel[ch] = (1-pos) * before.channel[ch] + pos * after.channel[ch];
@@ -188,6 +190,10 @@ static i_fcolor interp_i_fcolor(i_fcolor before, i_fcolor after, double pos,
        out.channel[ch] = I_LIMIT_DOUBLE(out_level);
       }
     }
+    else {
+      for (ch = 0; ch < channels-1; ++ch)
+       out.channel[ch] = 0;
+    }
 
     out.channel[channels-1] = total_cover;
   }
@@ -207,7 +213,6 @@ i_img *i_matrix_transform_bg(i_img *src, i_img_dim xsize, i_img_dim ysize, const
 #code src->bits <= 8
     IM_COLOR *vals = mymalloc(xsize * sizeof(IM_COLOR));
     IM_COLOR back;
-    i_fsample_t fsamp;
 
 #ifdef IM_EIGHT_BIT
     if (backp) {
@@ -215,6 +220,7 @@ i_img *i_matrix_transform_bg(i_img *src, i_img_dim xsize, i_img_dim ysize, const
     }
     else if (fbackp) {
       for (ch = 0; ch < src->channels; ++ch) {
+       i_fsample_t fsamp;
        fsamp = fbackp->channel[ch];
        back.channel[ch] = fsamp < 0 ? 0 : fsamp > 1 ? 255 : fsamp * 255;
       }
@@ -252,43 +258,50 @@ i_img *i_matrix_transform_bg(i_img *src, i_img_dim xsize, i_img_dim ysize, const
        if (fabs(sz) > 0.0000001 
            && sx >= -1 && sx < src->xsize
            && sy >= -1 && sy < src->ysize) {
+         double fsx = floor(sx);
+         double fsy = floor(sy);
+         i_img_dim bx = fsx;
+         i_img_dim by = fsy;
 
          ROT_DEBUG(fprintf(stderr, "map " i_DFp " to %g,%g\n", i_DFcp(x, y), sx, sy));
-         if (sx != (i_img_dim)sx) {
-           if (sy != (i_img_dim)sy) {
+         if (sx != fsx) {
+           double dx = sx - fsx;
+           if (sy != fsy) {
              IM_COLOR c[2][2]; 
              IM_COLOR ci2[2];
+             double dy = sy - fsy;
              ROT_DEBUG(fprintf(stderr, " both non-int\n"));
              for (i = 0; i < 2; ++i)
                for (j = 0; j < 2; ++j)
-                 if (IM_GPIX(src, floor(sx)+i, floor(sy)+j, &c[j][i]))
+                 if (IM_GPIX(src, bx+i, by+j, &c[j][i]))
                    c[j][i] = back;
              for (j = 0; j < 2; ++j)
-               ci2[j] = interp_i_color(c[j][0], c[j][1], sx, src->channels);
-             vals[x] = interp_i_color(ci2[0], ci2[1], sy, src->channels);
+               ci2[j] = interp_i_color(c[j][0], c[j][1], dx, src->channels);
+             vals[x] = interp_i_color(ci2[0], ci2[1], dy, src->channels);
            }
            else {
              IM_COLOR ci2[2];
              ROT_DEBUG(fprintf(stderr, " y int, x non-int\n"));
              for (i = 0; i < 2; ++i)
-               if (IM_GPIX(src, floor(sx)+i, sy, ci2+i))
+               if (IM_GPIX(src, bx+i, sy, ci2+i))
                  ci2[i] = back;
-             vals[x] = interp_i_color(ci2[0], ci2[1], sx, src->channels);
+             vals[x] = interp_i_color(ci2[0], ci2[1], dx, src->channels);
            }
          }
          else {
-           if (sy != (i_img_dim)sy) {
+           if (sy != fsy) {
              IM_COLOR ci2[2];
+             double dy = sy - fsy;
              ROT_DEBUG(fprintf(stderr, " x int, y non-int\n"));
              for (i = 0; i < 2; ++i)
-               if (IM_GPIX(src, sx, floor(sy)+i, ci2+i))
+               if (IM_GPIX(src, bx, by+i, ci2+i))
                  ci2[i] = back;
-             vals[x] = interp_i_color(ci2[0], ci2[1], sy, src->channels);
+             vals[x] = interp_i_color(ci2[0], ci2[1], dy, src->channels);
            }
            else {
              ROT_DEBUG(fprintf(stderr, " both int\n"));
              /* all the world's an integer */
-             if (IM_GPIX(src, sx, sy, vals+x))
+             if (IM_GPIX(src, bx, by, vals+x))
                vals[x] = back;
            }
          }
@@ -307,7 +320,6 @@ i_img *i_matrix_transform_bg(i_img *src, i_img_dim xsize, i_img_dim ysize, const
     /* don't interpolate for a palette based image */
     i_palidx *vals = mymalloc(xsize * sizeof(i_palidx));
     i_palidx back = 0;
-    i_color min;
     int minval = 256 * 4;
     i_img_dim ix, iy;
     i_color want_back;
@@ -338,7 +350,6 @@ i_img *i_matrix_transform_bg(i_img *src, i_img_dim xsize, i_img_dim ysize, const
       }
       if (tempval < minval) {
         back = i;
-        min = temp;
         minval = tempval;
       }
     }
@@ -402,7 +413,7 @@ i_matrix_mult(double *dest, const double *left, const double *right) {
 
 #define numfmt "%23g"
 
-ROT_DEBUG(static dump_mat(const char *name, double *f) {
+ROT_DEBUG(static void dump_mat(const char *name, double *f) {
   fprintf(stderr, "%s:\n  " numfmt " " numfmt " " numfmt "\n"
          "  " numfmt " " numfmt " " numfmt "\n"
          "  " numfmt " " numfmt " " numfmt "\n",
@@ -417,6 +428,8 @@ i_img *i_rotate_exact_bg(i_img *src, double amount,
   double temp[9], matrix[9];
   i_img_dim x1, x2, y1, y2, newxsize, newysize;
 
+  ROT_DEBUG(fprintf(stderr, "rotate angle %.20g\n", amount));
+
   /* first translate the centre of the image to (0,0) */
   xlate1[0] = 1;
   xlate1[2] = (src->xsize-1)/2.0;