first commit

CS4451/proj3/readppm.c

@@ -0,0 +1,33 @@
+
+#include <stdio.h>
+#include <assert.h>
+#include <stdlib.h>
+
+typedef struct _rgb {
+  unsigned char r,g,b;
+} rgb;
+
+typedef 
+struct _ppmimage {
+  int sizex,sizey;
+  rgb *color;
+} ppmimage;
+
+ppmimage read_ppmimage ( const char *name )
+{
+  ppmimage result;
+  int range;
+  FILE *fp = fopen(name,"rb");
+  if (!fp)
+    {
+      fprintf(stderr,"No file\n");
+      exit(1);
+    }
+  assert(getc(fp)=='P');
+  assert(getc(fp)=='6');
+  fscanf(fp,"%d%d%d\n",&result.sizex,&result.sizey,&range);
+  assert(range==255); // we'll use only rgb range 0...255 here
+  result.color = (rgb*)malloc(result.sizex*result.sizey*sizeof(rgb));
+  fread(result.color,sizeof(rgb),result.sizex*result.sizey,fp);
+  return result;
+}