rewrite HDR rle logic

tests/image_test.c

@@ -51,10 +51,24 @@ void test_ycbcr(void)
 }
 #endif
 
+float hdr_data[200][200][3];
+
 int main(int argc, char **argv)
 {
    int w,h;
    //test_ycbcr();
+
+   #if 0
+   // test hdr asserts
+   for (h=0; h < 100; h += 2)
+      for (w=0; w < 200; ++w)
+         hdr_data[h][w][0] = (float) rand(),
+         hdr_data[h][w][1] = (float) rand(),
+         hdr_data[h][w][2] = (float) rand();
+
+   stbi_write_hdr("output/test.hdr", 200,200,3,hdr_data[0][0]);
+   #endif
+
    if (argc > 1) {
       int i, n;