Add much faster image writer (binary instead of text).

andportnoy · Jan 12, 2019 · 752e5f4 · 752e5f4
1 parent 3574099
commit 752e5f4
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Showing 4 changed files with 14 additions and 4 deletions.
diff --git a/evolve_image.c b/evolve_image.c
@@ -186,7 +186,7 @@ void write_images(Image **images, size_t n_images) {
         sprintf(filename, "images/random%07lu.ppm", i);
         file = fopen(filename, "w");
         if (file) {
-            write_image(file, images[i]);
+            write_image_P6(file, images[i]);
             fclose(file);
             printf("\33[2K\rSaved image %lu...", i);
             fflush(stdout);

diff --git a/evolve_row.c b/evolve_row.c
@@ -207,7 +207,7 @@ void main_row_generation(int argc, char *argv[]) {
     image = generate_image((size_t)width, (size_t)height, chosen_row_evolver);
     file = fopen(argv[4], "w");
     if (file) {
-        write_image(file, image);
+        write_image_P6(file, image);
         fclose(file);
     } else {
         fprintf(stderr, "Failed to open file.\n");

diff --git a/image.c b/image.c
@@ -58,7 +58,7 @@ void print_image(const Image *image) {
     }
 }
 
-void write_image(FILE *file, const Image *image) {
+void write_image_P3(FILE *file, const Image *image) {
     size_t i, j;
 
     /* Print PPM header. */
@@ -72,6 +72,15 @@ void write_image(FILE *file, const Image *image) {
     }
 }
 
+void write_image_P6(FILE *file, const Image *image) {
+    /* Print PPM header. */
+    fprintf(file, "P6\n%lu %lu\n%d\n", image->width, image->height, COLOR_RANGE);
+    fwrite(image->pixels,
+           sizeof(*(image->pixels)),
+           (image->width)*(image->height),
+           file);
+}
+
 void set_random_image(Image *image) {
     size_t length;
     size_t i;

diff --git a/image.h b/image.h
@@ -21,7 +21,8 @@ void write_pixel(FILE *file, const Pixel *pixel);
 Pixel *pixel_at(const Image *image, size_t x, size_t y);
 void set_random_row(Pixel *row, size_t width);
 void print_image(const Image *image);
-void write_image(FILE *file, const Image *image);
+void write_image_P3(FILE *file, const Image *image);
+void write_image_P6(FILE *file, const Image *image);
 void set_random_image(Image *image);
 Image *malloc_image(size_t width, size_t height);
 Image *malloc_random_image(size_t width, size_t height);