Add missing blit.c to repository.

git-svn-id: file:///srv/caca.zoy.org/var/lib/svn/libpipi/trunk@3560 92316355-f0b4-4df1-b90c-862c8a59935f

pipi/combine/blit.c

@@ -0,0 +1,89 @@
+/*
+ *  libpipi       Pathetic image processing interface 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.
+ */
+
+/*
+ * mean.c: Mean computation function
+ */
+
+#include "config.h"
+
+#include <stdlib.h>
+
+#include "pipi.h"
+#include "pipi_internals.h"
+
+pipi_image_t *pipi_blit(pipi_image_t *img1, pipi_image_t *img2, int x, int y)
+{
+    pipi_image_t *dst;
+    pipi_pixels_t *img1p, *img2p, *dstp;
+    float *img1data, *img2data, *dstdata;
+    int dx, dy, w1, h1, w2, h2;
+
+    w1 = img1->w;
+    h1 = img1->h;
+    w2 = img2->w;
+    h2 = img2->h;
+
+    dst = pipi_copy(img1);
+    dstp = pipi_get_pixels(dst, PIPI_PIXELS_RGBA_F32);
+    dstdata = (float *)dstp->pixels;
+
+    img1p = pipi_get_pixels(img1, PIPI_PIXELS_RGBA_F32);
+    img1data = (float *)img1p->pixels;
+    img2p = pipi_get_pixels(img2, PIPI_PIXELS_RGBA_F32);
+    img2data = (float *)img2p->pixels;
+
+    for(dy = 0; dy < h2; dy++)
+    {
+        if (y + dy < 0)
+            continue;
+
+        if (y + dy >= h1)
+            break;
+
+        for(dx = 0; dx < w2; dx++)
+        {
+            float p, q;
+            double t1, t2;
+
+            if (x + dx < 0)
+                continue;
+
+            if (x + dx >= w1)
+                break;
+
+            t1 = img2data[4 * (dy * w2 + dx) + 3];
+            t2 = 1.0 - t1;
+
+            p = img1data[4 * ((y + dy) * w1 + (x + dx))];
+            q = img2data[4 * (dy * w2 + dx)];
+            dstdata[4 * ((y + dy) * w1 + (x + dx))] = t2 * p + t1 * q;
+
+            p = img1data[4 * ((y + dy) * w1 + (x + dx)) + 1];
+            q = img2data[4 * (dy * w2 + dx) + 1];
+            dstdata[4 * ((y + dy) * w1 + (x + dx)) + 1] = t2 * p + t1 * q;
+
+            p = img1data[4 * ((y + dy) * w1 + (x + dx)) + 2];
+            q = img2data[4 * (dy * w2 + dx) + 2];
+            dstdata[4 * ((y + dy) * w1 + (x + dx)) + 2] = t2 * p + t1 * q;
+
+            p = img1data[4 * ((y + dy) * w1 + (x + dx)) + 3];
+            q = img2data[4 * (dy * w2 + dx) + 3];
+            dstdata[4 * ((y + dy) * w1 + (x + dx)) + 3] = t2 * p + t1 * q;
+        }
+    }
+
+    return dst;
+}
+