From 10646b914b4d4f82f315e14d25de17dcd75dca34 Mon Sep 17 00:00:00 2001
From: Michael Orlitzky <michael@orlitzky.com>
Date: Thu, 3 Aug 2023 20:45:41 -0400
Subject: [PATCH] example.c: factor out svgtiny_diagram_from_path().

---
 example.c | 107 ++++++++++++++++++++++++++++++++----------------------
 1 file changed, 63 insertions(+), 44 deletions(-)

diff --git a/example.c b/example.c
index f582682..f6deced 100644
--- a/example.c
+++ b/example.c
@@ -65,63 +65,51 @@ void render_path(cairo_t *cr, float scale, struct svgtiny_shape *path) {
   }
 }
 
-
-int main(int argc, char** argv) {
-  int exit_code = 0;
-
-  /* Initial viewport width and height */
-  int width = 1024, height = 1024;
-  float scale = 1.0;
-  char* svgpath;
-  char* pngpath;
+/*
+ * @brief Parse an SVG file into an svgtiny_diagram structure.
+ *
+ * @param path
+ *   The path to the SVG file.
+ *
+ * @return If successful, a pointer to an @c svgtiny_diagram structure
+ *   is returned; if not, @c NULL is returned. You are expected to @c
+ *   svgtiny_free the result if it is valid.
+ */
+struct svgtiny_diagram* svgtiny_diagram_from_path(char* path,
+						  int width,
+						  int height) {
+  struct svgtiny_diagram *diagram;
 
   int fd;
-  size_t svgsize;
+  size_t bytecount;
   char *buffer;
   size_t bytesread;
   struct stat sb;
-
   svgtiny_code code;
-  struct svgtiny_diagram *diagram;
-  cairo_surface_t *surface;
-  cairo_t *cr = 0;
-  cairo_status_t cr_status;
-
-  unsigned int i;
-
-  /* Parse arguments, and maybe print usage */
-  if (argc < 3) {
-    printf("Usage: %s INPUT OUTPUT\n", argv[0]);
-    printf("Convert an SVG file (INPUT) to a PNG file (OUTPUT)\n");
-    return 2;
-  }
-
-  svgpath = argv[1];
-  pngpath = argv[2];
 
   /* load file into memory buffer */
-  fd = open(svgpath, O_RDONLY);
+  fd = open(path, O_RDONLY);
   if (fd == -1) {
-    perror(svgpath);
-    return 1;
+    perror(path);
+    return NULL;
   }
 
   if (fstat(fd, &sb)) {
-    perror(svgpath);
-    return 1;
+    perror(path);
+    return NULL;
   }
-  svgsize = sb.st_size;
+  bytecount = sb.st_size;
 
-  buffer = malloc(svgsize);
+  buffer = malloc(bytecount);
   if (!buffer) {
-    fprintf(stderr, "Unable to allocate %zd bytes\n", svgsize);
-    return 1;
+    fprintf(stderr, "Unable to allocate %zd bytes\n", bytecount);
+    return NULL;
   }
 
-  bytesread = read(fd, buffer, svgsize);
-  if (bytesread != svgsize) {
-    perror(svgpath);
-    return 1;
+  bytesread = read(fd, buffer, bytecount);
+  if (bytesread != bytecount) {
+    perror(path);
+    return NULL;
   }
   close(fd);
 
@@ -130,10 +118,10 @@ int main(int argc, char** argv) {
   diagram = svgtiny_create();
   if (!diagram) {
     fprintf(stderr, "svgtiny_create() failed\n");
-    return 1;
+    return NULL;
   }
 
-  code = svgtiny_parse(diagram, buffer, svgsize, svgpath, width, height);
+  code = svgtiny_parse(diagram, buffer, bytecount, path, width, height);
   free(buffer);
 
   if (code != svgtiny_OK) {
@@ -158,11 +146,42 @@ int main(int argc, char** argv) {
       break;
     }
     fprintf(stderr, "\n");
-    return 1;
+    return NULL;
   }
 
+  return diagram;
+}
+
+int main(int argc, char** argv) {
+  int exit_code = 0;
+
+  char* svgpath;
+  char* pngpath;
+  int pngwidth = 1024, pngheight = 1024;
+
+  float scale = 1.0;
+  struct svgtiny_diagram *diagram;
+  cairo_surface_t *surface;
+  cairo_t *cr = 0;
+  cairo_status_t cr_status;
+
+  unsigned int i;
+
+  /* Parse arguments, and maybe print usage */
+  if (argc < 3) {
+    printf("Usage: %s INPUT OUTPUT\n", argv[0]);
+    printf("Convert an SVG file (INPUT) to a PNG file (OUTPUT)\n");
+    return 2;
+  }
+
+  svgpath = argv[1];
+  pngpath = argv[2];
+
+  diagram = svgtiny_diagram_from_path(svgpath, pngwidth, pngheight);
 
-  surface = cairo_image_surface_create(CAIRO_FORMAT_RGB24, width, height);
+  surface = cairo_image_surface_create(CAIRO_FORMAT_RGB24,
+				       pngwidth,
+				       pngheight);
   if (!surface) {
     fprintf(stderr, "cairo_image_surface_create failed\n");
     exit_code = 1;
-- 
2.43.2