1 files changed, 141 insertions, 0 deletions
diff --git a/third_party/spiro/ppedit/image.c b/third_party/spiro/ppedit/image.c
new file mode 100644
index 0000000..215d27d
--- /dev/null
+++ b/third_party/spiro/ppedit/image.c
@@ -0,0 +1,141 @@
+/*
+ppedit - A pattern plate editor for Spiro splines.
+Copyright (C) 2007 Raph Levien
+
+This program is free software; you can redistribute it and/or
+modify it under the terms of the GNU General Public License
+as published by the Free Software Foundation; either version 2
+of the License, or (at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+02110-1301, USA.
+
+*/
+#include <stdio.h>
+#include <string.h>
+#include "zmisc.h"
+#include "image.h"
+
+/* An image loaded into memory. */
+struct _image {
+    unsigned char *buf;
+    int width;
+    int height;
+    int rowstride;
+};
+
+static image *
+load_ppm_file(FILE *f, char **reason)
+{
+    image *result;
+    char line[256];
+    int xs, ys;
+    int depth;
+    int n;
+
+    fseek(f, 0, SEEK_SET);
+    fgets(line, sizeof(line), f);
+    do {
+	fgets(line, sizeof(line), f);
+    } while (line[0] == '#');
+    n = sscanf(line, "%d %d", &xs, &ys);
+    if (n != 2) {
+	*reason = "Error reading ppmraw size line";
+	fclose(f);
+	return NULL;
+    }
+    do {
+	fgets(line, sizeof(line), f);
+    } while (line[0] == '#');
+    n = sscanf(line, "%d", &depth);
+    if (n != 1) {
+	*reason = "Error reading ppmraw depth line";
+	fclose(f);
+	return NULL;
+    }
+    result = znew(image, 1);
+    result->rowstride = 3 * xs;
+    result->buf = zalloc(ys * result->rowstride);
+    result->width = xs;
+    result->height = ys;
+    fread(result->buf, 1, ys * result->rowstride, f);
+    fclose(f);
+    return result;
+}
+
+image *
+load_image_file(const char *fn, char **reason)
+{
+    FILE *f = fopen(fn, "rb");
+    unsigned char buf[256];
+    int n;
+
+    if (f == NULL) {
+	*reason = "Error opening file";
+	return NULL;
+    }
+    n = fread(buf, 1, sizeof(buf), f);
+    if (n < 4) {
+	*reason = "Short file";
+	fclose(f);
+	return NULL;
+    }
+    if (buf[0] != 'P' || buf[1] != '6') {
+	*reason = "Unrecognized magic";
+	fclose(f);
+	return NULL;
+    }
+    return load_ppm_file(f, reason);
+}
+
+void
+free_image(image *im)
+{
+    zfree(im->buf);
+    zfree(im);
+}
+
+void
+render_image(image *im, const double affine[6],
+	     unsigned char *buf, int rowstride, int x0, int y0, int x1, int y1)
+{
+    int y;
+    unsigned char *dest_line = buf;
+    int src_x0 = x0;
+
+    for (y = y0; y < y1; y++) {
+	int src_y = y;
+
+	if (src_y >= 0 && src_y < im->height) {
+	    unsigned char *img_line = im->buf + src_y * im->rowstride;
+	    int left_pad = -src_x0;
+	    int img_run, img_off, right_pad;
+
+	    if (left_pad > x1 - x0) left_pad = x1 - x0;
+	    if (left_pad > 0) {
+		memset(dest_line, 255, 3 * left_pad);
+	    } else left_pad = 0;
+	    img_off = src_x0;
+	    if (img_off < 0) img_off = 0;
+	    img_run = x1 - x0 - left_pad;
+	    if (img_run > im->width - img_off) img_run = im->width - img_off;
+	    if (img_run > 0) {
+		memcpy(dest_line + 3 * left_pad, img_line + 3 * img_off, 3 * img_run);
+	    } else img_run = 0;
+	    right_pad = x1 - x0 - left_pad - img_run;
+	    if (right_pad > 0) {
+		memset(dest_line + 3 * (left_pad + img_run), 255, 3 * right_pad);
+	    }
+	} else {
+	    memset(dest_line, 255, rowstride);
+	}
+	dest_line += rowstride;
+    }
+}