Move utility functions from main.c to util.c

1 files changed, 128 insertions, 0 deletions

diff --git a/src/util.c b/src/util.c
new file mode 100644
index 0000000..3902157
--- /dev/null
+++ b/src/util.c
@@ -0,0 +1,128 @@
+/* Copyright (c) 2015 Harry Jeffery
+
+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 "util.h"
+
+#include <fontconfig/fontconfig.h>
+
+TTF_Font *load_font(const char *font_spec)
+{
+  int font_size;
+  char *font_name;
+
+  /* figure out font size from name, or default to 24 */
+  char *sep = strchr(font_spec, ':');
+  if(sep) {
+    font_name = strndup(font_spec, sep - font_spec);
+    font_size = strtol(sep+1, NULL, 10);
+  } else {
+    font_name = strdup(font_spec);
+    font_size = 24;
+  }
+
+
+  FcConfig *cfg = FcInitLoadConfigAndFonts();
+  FcPattern *pattern = FcNameParse((const FcChar8*)font_name);
+  FcConfigSubstitute(cfg, pattern, FcMatchPattern);
+  FcDefaultSubstitute(pattern);
+
+  TTF_Font *ret = NULL;
+
+  FcResult result = FcResultNoMatch;
+  FcPattern* font = FcFontMatch(cfg, pattern, &result);
+  if (font) {
+    FcChar8 *path = NULL;
+    if (FcPatternGetString(font, FC_FILE, 0, &path) == FcResultMatch) {
+      ret = TTF_OpenFont((char*)path, font_size);
+    }
+    FcPatternDestroy(font);
+  }
+  FcPatternDestroy(pattern);
+
+  free(font_name);
+  return ret;
+}
+
+SDL_Texture *create_chequered(SDL_Renderer *renderer)
+{
+  SDL_RendererInfo ri;
+  SDL_GetRendererInfo(renderer, &ri);
+  int width = 512;
+  int height = 512;
+  if(ri.max_texture_width != 0 && ri.max_texture_width < width) {
+    width = ri.max_texture_width;
+  }
+  if(ri.max_texture_height != 0 && ri.max_texture_height < height) {
+    height = ri.max_texture_height;
+  }
+  const int box_size = 16;
+  /* Create a chequered texture */
+  const unsigned char l = 196;
+  const unsigned char d = 96;
+
+  size_t pixels_len = 3 * width * height;
+  unsigned char *pixels = malloc(pixels_len);
+  for(int y = 0; y < height; y++) {
+    for(int x = 0; x < width; x += box_size) {
+      unsigned char color = l;
+      if(((x/box_size) % 2 == 0) ^ ((y/box_size) % 2 == 0)) {
+        color = d;
+      }
+      memset(pixels + 3 * x + 3 * width * y, color, 3 * box_size);
+    }
+  }
+  SDL_Texture *ret = SDL_CreateTexture(renderer, SDL_PIXELFORMAT_RGB24,
+    SDL_TEXTUREACCESS_STATIC,
+    width, height);
+  SDL_UpdateTexture(ret, NULL, pixels, 3 * width);
+  free(pixels);
+  return ret;
+}
+
+static int parse_hex_digit(char c) {
+  if(c >= '0' && c <= '9') {
+    return c - '0';
+  } else if (c >= 'a' && c <= 'f') {
+    return c - 'a' + 10;
+  } else if (c >= 'A' && c <= 'F') {
+    return c - 'A' + 10;
+  }
+  return -1;
+}
+
+int parse_hex_color(const char* str,
+  unsigned char *r, unsigned char *g, unsigned char *b)
+{
+  if(str[0] == '#') {
+    ++str;
+  }
+
+  if(strlen(str) != 6) {
+    return 1;
+  }
+
+  for(int i = 0; i < 6; ++i) {
+    if(!isxdigit(str[i])) {
+      return 1;
+    }
+  }
+
+  *r = (parse_hex_digit(str[0]) << 4) + parse_hex_digit(str[1]);
+  *g = (parse_hex_digit(str[2]) << 4) + parse_hex_digit(str[3]);
+  *b = (parse_hex_digit(str[4]) << 4) + parse_hex_digit(str[5]);
+  return 0;
+}