fix bug in handling rectangle with width or height of 0

stb_rect_pack.h

@@ -1,4 +1,4 @@
-// stb_rect_pack.h - v0.06 - public domain - rectangle packing
+// stb_rect_pack.h - v0.07 - public domain - rectangle packing
 // Sean Barrett 2014
 //
 // Useful for e.g. packing rectangular textures into an atlas.
@@ -28,10 +28,11 @@
 //  Minor features
 //    Martins Mozeiko
 //  Bugfixes / warning fixes
-//    [your name could be here]
+//    Jeremy Jaussaud
 //
 // Version history:
 //
+//     0.07  (2015-09-13)  fix bug with empty rects (w=0 or h=0)
 //     0.06  (2015-04-15)  added STBRP_SORT to allow replacing qsort
 //     0.05:  added STBRP_ASSERT to allow replacing assert
 //     0.04:  fixed minor bug in STBRP_LARGE_RECTS support
@@ -548,6 +549,10 @@ STBRP_DEF void stbrp_pack_rects(stbrp_context *context, stbrp_rect *rects, int n
 
    for (i=0; i < num_rects; ++i) {
       stbrp__findresult fr = stbrp__skyline_pack_rectangle(context, rects[i].w, rects[i].h);
+
+      if (rects[i].w == 0 || rects[i].h == 0) {
+         rects[i].x = rects[i].y = 0;  // empty rect needs no space
+      } else {
          if (fr.prev_link) {
             rects[i].x = (stbrp_coord) fr.x;
             rects[i].y = (stbrp_coord) fr.y;
@@ -555,6 +560,7 @@ STBRP_DEF void stbrp_pack_rects(stbrp_context *context, stbrp_rect *rects, int n
             rects[i].x = rects[i].y = STBRP__MAXVAL;
          }
       }
+   }
 
    // unsort
    STBRP_SORT(rects, num_rects, sizeof(rects[0]), rect_original_order);