Implement basic PPM image writer

ppm.c

@@ -0,0 +1,22 @@
+#include "ppm.h"
+#include "aliases.h"
+#include <stdio.h>
+#include <string.h>
+
+void write_p6_ppm(const char *filepath, u64 width, u64 height, Pixel *data) {
+  FILE *fp = fopen(filepath, "wb");
+  if (!fp) {
+    return;
+  }
+
+  char header[1024] = {0};
+  sprintf(header, "P6\n%lu %lu\n255\n", width, height);
+
+  u64 length = strlen(header);
+  fwrite(&header, length, 1, fp);
+
+  u64 pixel_count = width * height;
+  fwrite(data, sizeof(Pixel), pixel_count, fp);
+
+  fclose(fp);
+}

ppm.h

@@ -0,0 +1,9 @@
+#include "aliases.h"
+
+typedef struct {
+  u8 r;
+  u8 g;
+  u8 b;
+} Pixel;
+
+void write_p6_ppm(const char *filepath, u64 width, u64 height, Pixel *data);