Add Image struct

ppm.c

@@ -3,21 +3,21 @@
 #include <stdio.h>
 #include <string.h>
 
-void write_p6_ppm(const char *filepath, u64 width, u64 height, Pixel *data) {
+void write_p6_ppm(const char *filepath, Image *img) {
   FILE *fp = fopen(filepath, "wb");
   if (!fp) {
     return;
   }
 
   char header[1024] = {0};
-  sprintf(header, "P6\n%llu %llu\n255\n", (unsigned long long)width,
-          (unsigned long long)height);
+  sprintf(header, "P6\n%llu %llu\n255\n", (unsigned long long)img->width,
+          (unsigned long long)img->height);
 
   u64 length = strlen(header);
   fwrite(&header, length, 1, fp);
 
-  u64 pixel_count = width * height;
-  fwrite(data, sizeof(Pixel), pixel_count, fp);
+  u64 pixel_count = img->width * img->height;
+  fwrite(img->data, sizeof(Pixel), pixel_count, fp);
 
   fclose(fp);
 }

ppm.h

@@ -6,4 +6,10 @@ typedef struct {
   u8 b;
 } Pixel;
 
-void write_p6_ppm(const char *filepath, u64 width, u64 height, Pixel *data);
+typedef struct {
+	u64 width;
+	u64 height;
+	Pixel *data;
+} Image;
+
+void write_p6_ppm(const char *filepath, Image *img);