* convolution.c: support for wrap-around in convolutions.

* pipi.c: add the "--wrap" flag to tell libpipi that a given image wraps
    around.

git-svn-id: file:///srv/caca.zoy.org/var/lib/svn/libpipi/trunk@2703 92316355-f0b4-4df1-b90c-862c8a59935f

pipi/context.c

@@ -131,6 +131,12 @@ int pipi_command(pipi_context_t *ctx, char const *cmd, ...)
         pipi_free(src);
         ctx->images[ctx->nimages - 1] = dst;
     }
+    else if(!strcmp(cmd, "wrap"))
+    {
+        if(ctx->nimages <= 0)
+            return -1;
+        ctx->images[ctx->nimages - 1]->wrap = 1;
+    }
     else if(!strcmp(cmd, "gray"))
     {
         if(ctx->nimages <= 0)

pipi/filter/convolution.c

@@ -27,6 +27,12 @@
 #include "pipi.h"
 #include "pipi_internals.h"
 
+#define FLAG_GRAY ((FLAGS) & SET_FLAG_GRAY)
+#define FLAG_WRAP ((FLAGS) & SET_FLAG_WRAP)
+
+#define SET_FLAG_GRAY 0x01
+#define SET_FLAG_WRAP 0x02
+
 static pipi_image_t *conv_std_rgba_f(pipi_image_t *src,
                                      int m, int n, double mat[]);
 static pipi_image_t *conv_sep_rgba_f(pipi_image_t *src,
@@ -35,11 +41,11 @@ static pipi_image_t *conv_sep_rgba_f(pipi_image_t *src,
 #undef FUNC1
 #undef FUNC2
 #undef PIXEL
-#undef GRAY
+#undef FLAGS
 #define FUNC1 conv_std_rgba_f
 #define FUNC2 conv_sep_rgba_f
 #define PIXEL float
-#define GRAY 0
+#define FLAGS 0
 #include "convolution_template.h"
 
 static pipi_image_t *conv_std_y_f(pipi_image_t *src,
@@ -50,11 +56,41 @@ static pipi_image_t *conv_sep_y_f(pipi_image_t *src,
 #undef FUNC1
 #undef FUNC2
 #undef PIXEL
-#undef GRAY
+#undef FLAGS
 #define FUNC1 conv_std_y_f
 #define FUNC2 conv_sep_y_f
 #define PIXEL float
-#define GRAY 1
+#define FLAGS SET_FLAG_GRAY
+#include "convolution_template.h"
+
+static pipi_image_t *wrap_std_rgba_f(pipi_image_t *src,
+                                     int m, int n, double mat[]);
+static pipi_image_t *wrap_sep_rgba_f(pipi_image_t *src,
+                                     int m, double hvec[],
+                                     int n, double vvec[]);
+#undef FUNC1
+#undef FUNC2
+#undef PIXEL
+#undef FLAGS
+#define FUNC1 wrap_std_rgba_f
+#define FUNC2 wrap_sep_rgba_f
+#define PIXEL float
+#define FLAGS SET_FLAG_WRAP
+#include "convolution_template.h"
+
+static pipi_image_t *wrap_std_y_f(pipi_image_t *src,
+                                  int m, int n, double mat[]);
+static pipi_image_t *wrap_sep_y_f(pipi_image_t *src,
+                                  int m, double hvec[],
+                                  int n, double vvec[]);
+#undef FUNC1
+#undef FUNC2
+#undef PIXEL
+#undef FLAGS
+#define FUNC1 wrap_std_y_f
+#define FUNC2 wrap_sep_y_f
+#define PIXEL float
+#define FLAGS SET_FLAG_GRAY|SET_FLAG_WRAP
 #include "convolution_template.h"
 
 pipi_image_t *pipi_convolution(pipi_image_t *src, int m, int n, double mat[])
@@ -97,9 +133,17 @@ pipi_image_t *pipi_convolution(pipi_image_t *src, int m, int n, double mat[])
             if(fabs(p - q) > 0.0001 * 0.0001)
             {
                 if(src->last_modified == PIPI_PIXELS_Y_F)
+                {
+                    if(src->wrap)
+                        return wrap_std_y_f(src, m, n, mat);
                     return conv_std_y_f(src, m, n, mat);
+                }
                 else
+                {
+                    if(src->wrap)
+                        return wrap_std_rgba_f(src, m, n, mat);
                     return conv_std_rgba_f(src, m, n, mat);
+                }
             }
         }
     }
@@ -115,9 +159,11 @@ pipi_image_t *pipi_convolution(pipi_image_t *src, int m, int n, double mat[])
         vvec[j] = mat[j * m + besti] / tmp;
 
     if(src->last_modified == PIPI_PIXELS_Y_F)
-        ret = conv_sep_y_f(src, m, hvec, n, vvec);
+        ret = src->wrap ? wrap_sep_y_f(src, m, hvec, n, vvec)
+                        : conv_sep_y_f(src, m, hvec, n, vvec);
     else
-        ret = conv_sep_rgba_f(src, m, hvec, n, vvec);
+        ret = src->wrap ? wrap_sep_rgba_f(src, m, hvec, n, vvec)
+                        : conv_sep_rgba_f(src, m, hvec, n, vvec);
 
     free(hvec);
     free(vvec);

pipi/filter/convolution_template.h

@@ -18,7 +18,8 @@
  *   FUNC1  standard function name
  *   FUNC2  separable function name
  *   PIXEL  pixel type
- *   GRAY   1 (grayscale) or 0 (classic RGBA)
+ *   FLAGS  1 (grayscale)
+ *          2 (loop)
  */
 
 static pipi_image_t *FUNC1(pipi_image_t *src, int m, int n, double mat[])
@@ -31,20 +32,20 @@ static pipi_image_t *FUNC1(pipi_image_t *src, int m, int n, double mat[])
     w = src->w;
     h = src->h;
 
-    srcp = GRAY ? pipi_getpixels(src, PIPI_PIXELS_Y_F)
-                : pipi_getpixels(src, PIPI_PIXELS_RGBA_F);
+    srcp = FLAG_GRAY ? pipi_getpixels(src, PIPI_PIXELS_Y_F)
+                     : pipi_getpixels(src, PIPI_PIXELS_RGBA_F);
     srcdata = (PIXEL *)srcp->pixels;
 
     dst = pipi_new(w, h);
-    dstp = GRAY ? pipi_getpixels(dst, PIPI_PIXELS_Y_F)
-                : pipi_getpixels(dst, PIPI_PIXELS_RGBA_F);
+    dstp = FLAG_GRAY ? pipi_getpixels(dst, PIPI_PIXELS_Y_F)
+                     : pipi_getpixels(dst, PIPI_PIXELS_RGBA_F);
     dstdata = (PIXEL *)dstp->pixels;
 
     for(y = 0; y < h; y++)
     {
         for(x = 0; x < w; x++)
         {
-            if(GRAY)
+            if(FLAG_GRAY)
             {
                 double Y = 0.;
                 int x2, y2;
@@ -52,14 +53,14 @@ static pipi_image_t *FUNC1(pipi_image_t *src, int m, int n, double mat[])
                 for(j = 0; j < n; j++)
                 {
                     y2 = y + j - n / 2;
-                    if(y2 < 0) y2 = 0;
-                    else if(y2 >= h) y2 = h - 1;
+                    if(y2 < 0) y2 = FLAG_WRAP ? (h - 1 - (-y2 - 1) % h) : 0;
+                    else if(y2 >= h) y2 = FLAG_WRAP ? y2 % h : h - 1;
 
                     for(i = 0; i < m; i++)
                     {
                         x2 = x + i - m / 2;
-                        if(x2 < 0) x2 = 0;
-                        else if(x2 >= w) x2 = w - 1;
+                        if(x2 < 0) x2 = FLAG_WRAP ? (w - 1 - (-x2 - 1) % w) : 0;
+                        else if(x2 >= w) x2 = FLAG_WRAP ? x2 % w : w - 1;
 
                         Y += mat[j * m + i] * srcdata[y2 * w + x2];
                     }
@@ -75,16 +76,16 @@ static pipi_image_t *FUNC1(pipi_image_t *src, int m, int n, double mat[])
                 for(j = 0; j < n; j++)
                 {
                     y2 = y + j - n / 2;
-                    if(y2 < 0) y2 = 0;
-                    else if(y2 >= h) y2 = h - 1;
+                    if(y2 < 0) y2 = FLAG_WRAP ? (h - 1 - (-y2 - 1) % h) : 0;
+                    else if(y2 >= h) y2 = FLAG_WRAP ? y2 % h : h - 1;
 
                     for(i = 0; i < m; i++)
                     {
                         double f = mat[j * m + i];
 
                         x2 = x + i - m / 2;
-                        if(x2 < 0) x2 = 0;
-                        else if(x2 >= w) x2 = w - 1;
+                        if(x2 < 0) x2 = FLAG_WRAP ? (w - 1 - (-x2 - 1) % w) : 0;
+                        else if(x2 >= w) x2 = FLAG_WRAP ? x2 % w : w - 1;
 
                         R += f * srcdata[(y2 * w + x2) * 4];
                         G += f * srcdata[(y2 * w + x2) * 4 + 1];
@@ -114,22 +115,22 @@ static pipi_image_t *FUNC2(pipi_image_t *src,
     w = src->w;
     h = src->h;
 
-    srcp = GRAY ? pipi_getpixels(src, PIPI_PIXELS_Y_F)
-                : pipi_getpixels(src, PIPI_PIXELS_RGBA_F);
+    srcp = FLAG_GRAY ? pipi_getpixels(src, PIPI_PIXELS_Y_F)
+                     : pipi_getpixels(src, PIPI_PIXELS_RGBA_F);
     srcdata = (PIXEL *)srcp->pixels;
 
     dst = pipi_new(w, h);
-    dstp = GRAY ? pipi_getpixels(dst, PIPI_PIXELS_Y_F)
-                : pipi_getpixels(dst, PIPI_PIXELS_RGBA_F);
+    dstp = FLAG_GRAY ? pipi_getpixels(dst, PIPI_PIXELS_Y_F)
+                     : pipi_getpixels(dst, PIPI_PIXELS_RGBA_F);
     dstdata = (PIXEL *)dstp->pixels;
 
-    buffer = malloc(w * h * (GRAY ? 1 : 4) * sizeof(double));
+    buffer = malloc(w * h * (FLAG_GRAY ? 1 : 4) * sizeof(double));
 
     for(y = 0; y < h; y++)
     {
         for(x = 0; x < w; x++)
         {
-            if(GRAY)
+            if(FLAG_GRAY)
             {
                 double Y = 0.;
                 int x2;
@@ -137,8 +138,8 @@ static pipi_image_t *FUNC2(pipi_image_t *src,
                 for(i = 0; i < m; i++)
                 {
                     x2 = x + i - m / 2;
-                    if(x2 < 0) x2 = 0;
-                    else if(x2 >= w) x2 = w - 1;
+                    if(x2 < 0) x2 = FLAG_WRAP ? (w - 1 - (-x2 - 1) % w) : 0;
+                    else if(x2 >= w) x2 = FLAG_WRAP ? x2 % w : w - 1;
 
                     Y += hvec[i] * srcdata[y * w + x2];
                 }
@@ -155,8 +156,8 @@ static pipi_image_t *FUNC2(pipi_image_t *src,
                     double f = hvec[i];
 
                     x2 = x + i - m / 2;
-                    if(x2 < 0) x2 = 0;
-                    else if(x2 >= w) x2 = w - 1;
+                    if(x2 < 0) x2 = FLAG_WRAP ? (w - 1 - (-x2 - 1) % w) : 0;
+                    else if(x2 >= w) x2 = FLAG_WRAP ? x2 % w : w - 1;
 
                     R += f * srcdata[(y * w + x2) * 4];
                     G += f * srcdata[(y * w + x2) * 4 + 1];
@@ -174,7 +175,7 @@ static pipi_image_t *FUNC2(pipi_image_t *src,
     {
         for(x = 0; x < w; x++)
         {
-            if(GRAY)
+            if(FLAG_GRAY)
             {
                 double Y = 0.;
                 int y2;
@@ -182,8 +183,8 @@ static pipi_image_t *FUNC2(pipi_image_t *src,
                 for(j = 0; j < n; j++)
                 {
                     y2 = y + j - n / 2;
-                    if(y2 < 0) y2 = 0;
-                    else if(y2 >= h) y2 = h - 1;
+                    if(y2 < 0) y2 = FLAG_WRAP ? (h - 1 - (-y2 - 1) % h) : 0;
+                    else if(y2 >= h) y2 = FLAG_WRAP ? y2 % h : h - 1;
 
                     Y += vvec[j] * buffer[y2 * w + x];
                 }
@@ -200,8 +201,8 @@ static pipi_image_t *FUNC2(pipi_image_t *src,
                     double f = vvec[j];
 
                     y2 = y + j - n / 2;
-                    if(y2 < 0) y2 = 0;
-                    else if(y2 >= h) y2 = h - 1;
+                    if(y2 < 0) y2 = FLAG_WRAP ? (h - 1 - (-y2 - 1) % h) : 0;
+                    else if(y2 >= h) y2 = FLAG_WRAP ? y2 % h : h - 1;
 
                     R += f * buffer[(y2 * w + x) * 4];
                     G += f * buffer[(y2 * w + x) * 4 + 1];

pipi/pipi.c

@@ -57,6 +57,10 @@ pipi_image_t *pipi_copy(pipi_image_t *src)
 {
     pipi_image_t *dst = pipi_new(src->w, src->h);
 
+    /* Copy properties */
+    dst->wrap = src->wrap;
+
+    /* Copy pixels, if any */
     if(src->last_modified != PIPI_PIXELS_UNINITIALISED)
     {
         pipi_pixels_t *srcp, *dstp;

pipi/pipi_internals.h

@@ -25,6 +25,7 @@
 struct pipi_image
 {
     int w, h, pitch;
+    int wrap;
     pipi_format_t codec_format, last_modified;
 
     /* List of all possible pixel formats */

src/pipi.c

@@ -41,6 +41,11 @@ int main(int argc, char *argv[])
             if(pipi_command(ctx, "gray") != 0)
                 return EXIT_FAILURE;
         }
+        else if(!strcmp(argv[0], "--wrap"))
+        {
+            if(pipi_command(ctx, "wrap") != 0)
+                return EXIT_FAILURE;
+        }
         else if(!strcmp(argv[0], "--output") || !strcmp(argv[0], "-o"))
         {
             if(argv[1] == NULL)