* codec.c: support for stock images in pipi_load().

* stock.c: start working on stock image generation; for instance:
      pipi pipi:bayer64 -o image.png
    will generate a 64x64 Bayer dithering pattern and save it to image.png.

git-svn-id: file:///srv/caca.zoy.org/var/lib/svn/libpipi/trunk@2695 92316355-f0b4-4df1-b90c-862c8a59935f

pipi/Makefile.am

@@ -19,6 +19,7 @@ libpipi_la_SOURCES = \
 	context.c \
 	pixels.c \
 	codec.c \
+	stock.c \
 	resize.c \
 	dither.c \
 	measure.c \

pipi/codec.c

@@ -16,17 +16,21 @@
  * codec.c: image I/O functions
  */
 
-#include <stdio.h>
-#include <stdlib.h>
-
 #include "config.h"
 #include "common.h"
 
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
 #include "pipi.h"
 #include "pipi_internals.h"
 
-pipi_image_t *pipi_load(const char *name)
+pipi_image_t *pipi_load(char const *name)
 {
+    if(!strncmp(name, "pipi:", 5))
+        return pipi_load_stock(name + 5);
+
 #if USE_IMLIB2
     return pipi_load_imlib2(name);
 #elif USE_OPENCV

pipi/pipi.h

@@ -71,7 +71,8 @@ extern pipi_context_t *pipi_create_context(void);
 extern void pipi_destroy_context(pipi_context_t *);
 extern int pipi_command(pipi_context_t *, char const *, ...);
 
-extern pipi_image_t *pipi_load(const char *);
+extern pipi_image_t *pipi_load(char const *);
+extern pipi_image_t *pipi_load_stock(char const *);
 extern pipi_image_t *pipi_new(int, int);
 extern pipi_image_t *pipi_copy(pipi_image_t *);
 extern void pipi_free(pipi_image_t *);

pipi/stock.c

@@ -0,0 +1,70 @@
+/*
+ *  libpipi       Proper image processing implementation library
+ *  Copyright (c) 2004-2008 Sam Hocevar <sam@zoy.org>
+ *                All Rights Reserved
+ *
+ *  $Id$
+ *
+ *  This library is free software. It comes without any warranty, to
+ *  the extent permitted by applicable law. You can redistribute it
+ *  and/or modify it under the terms of the Do What The Fuck You Want
+ *  To Public License, Version 2, as published by Sam Hocevar. See
+ *  http://sam.zoy.org/wtfpl/COPYING for more details.
+ */
+
+/*
+ * stock.c: stock images
+ */
+
+#include "config.h"
+#include "common.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "pipi.h"
+#include "pipi_internals.h"
+
+pipi_image_t *pipi_load_stock(char const *name)
+{
+    pipi_image_t *ret;
+    pipi_pixels_t *pix;
+    float *data;
+
+    /* Generate a Bayer dithering pattern. */
+    if(!strncmp(name, "bayer", 5))
+    {
+        int i, j, n = atoi(name + 5);
+
+        if(n <= 0 || (n & (n - 1))) /* is n a power of two? */
+            return NULL;
+
+        ret = pipi_new(n, n);
+        pix = pipi_getpixels(ret, PIPI_PIXELS_Y_F);
+        data = (float *)pix->pixels;
+
+        for(j = 0; j < n; j++)
+            for(i = 0; i < n; i++)
+            {
+                int k, l, x = 0;
+
+                for(k = 1, l = n * n / 4; k < n; k *= 2, l /= 4)
+                {
+                    if((i & k) && (j & k))
+                        x += l;
+                    else if(i & k)
+                        x += 3 * l;
+                    else if(j & k)
+                        x += 2 * l;
+                }
+
+                data[j * n + i] = (double)(x + 1) / (n * n + 1);
+            }
+
+        return ret;
+    }
+
+    return NULL;
+}
+