cogl-texture-2d-sliced: Fix the foreach callback for waste textures

When converting the virtual coordinates of the underlying texture for
a slice to virtual coordinates for the whole texture it was using the
size and offset of the intersection as the size of the child
texture. This would be incorrect if the texture contains waste or the
texture coordinates are not the default. Instead the sliced foreach
function now passes the CoglSpan to the callback instead of the
intersection.

http://bugzilla.clutter-project.org/show_bug.cgi?id=2398

diff --git a/clutter/cogl/cogl/cogl-texture-2d-sliced.c b/clutter/cogl/cogl/cogl-texture-2d-sliced.c
index 5f566b6..9a6aa0f 100644 (file)
--- a/clutter/cogl/cogl/cogl-texture-2d-sliced.c
+++ b/clutter/cogl/cogl/cogl-texture-2d-sliced.c
@@ -59,10 +59,8 @@ static const CoglTextureVtable cogl_texture_2d_sliced_vtable;
 typedef struct
 {
   CoglTexture2DSliced *tex;
-  float x_intersect_start;
-  float x_intersect_end;
-  float y_intersect_start;
-  float y_intersect_end;
+  CoglSpan *x_span;
+  CoglSpan *y_span;
 
   CoglTextureSliceCallback callback;
   void *user_data;
@@ -81,18 +79,14 @@ _cogl_texture_2d_sliced_foreach_cb (CoglHandle handle,
 
   /* Convert the virtual coordinates of the texture slice back to
      coordinates in the space of the outer texture */
-  virtual_coords_out[0] = (virtual_coords_in[0] *
-                           (data->x_intersect_end - data->x_intersect_start) +
-                           data->x_intersect_start) / data->tex->width;
-  virtual_coords_out[1] = (virtual_coords_in[1] *
-                           (data->y_intersect_end - data->y_intersect_start) +
-                           data->y_intersect_start) / data->tex->height;
-  virtual_coords_out[2] = (virtual_coords_in[2] *
-                           (data->x_intersect_end - data->x_intersect_start) +
-                           data->x_intersect_start) / data->tex->width;
-  virtual_coords_out[3] = (virtual_coords_in[3] *
-                           (data->y_intersect_end - data->y_intersect_start) +
-                           data->y_intersect_start) / data->tex->height;
+  virtual_coords_out[0] = (virtual_coords_in[0] * data->x_span->size +
+                           data->x_span->start) / data->tex->width;
+  virtual_coords_out[1] = (virtual_coords_in[1] * data->y_span->size +
+                           data->y_span->start) / data->tex->height;
+  virtual_coords_out[2] = (virtual_coords_in[2] * data->x_span->size +
+                           data->x_span->start) / data->tex->width;
+  virtual_coords_out[3] = (virtual_coords_in[3] * data->y_span->size +
+                           data->y_span->start) / data->tex->height;
 
   data->callback (data->tex,
                   gl_handle,
@@ -151,30 +145,31 @@ _cogl_texture_2d_sliced_foreach_sub_texture_in_region (
        !_cogl_span_iter_end (&iter_y);
        _cogl_span_iter_next (&iter_y))
     {
+      float y_intersect_start = iter_y.intersect_start;
+      float y_intersect_end = iter_y.intersect_end;
       float slice_ty1;
       float slice_ty2;
 
-      data.y_intersect_start = iter_y.intersect_start;
-      data.y_intersect_end = iter_y.intersect_end;
-
       /* Discard slices out of rectangle early */
       if (!iter_y.intersects)
         continue;
 
       if (iter_y.flipped)
         {
-          data.y_intersect_start = iter_y.intersect_end;
-          data.y_intersect_end = iter_y.intersect_start;
+          y_intersect_start = iter_y.intersect_end;
+          y_intersect_end = iter_y.intersect_start;
         }
 
       /* Localize slice texture coordinates */
-      slice_ty1 = data.y_intersect_start - iter_y.pos;
-      slice_ty2 = data.y_intersect_end - iter_y.pos;
+      slice_ty1 = y_intersect_start - iter_y.pos;
+      slice_ty2 = y_intersect_end - iter_y.pos;
 
       /* Normalize slice texture coordinates */
       slice_ty1 /= iter_y.span->size;
       slice_ty2 /= iter_y.span->size;
 
+      data.y_span = iter_y.span;
+
       /* Iterate the x axis of the virtual rectangle */
       for (_cogl_span_iter_begin (&iter_x,
                                   tex_2ds->slice_x_spans,
@@ -184,31 +179,32 @@ _cogl_texture_2d_sliced_foreach_sub_texture_in_region (
           !_cogl_span_iter_end (&iter_x);
           _cogl_span_iter_next (&iter_x))
         {
+          float x_intersect_start = iter_x.intersect_start;
+          float x_intersect_end = iter_x.intersect_end;
           float slice_tx1;
           float slice_tx2;
           CoglHandle slice_tex;
 
-          data.x_intersect_start = iter_x.intersect_start;
-          data.x_intersect_end = iter_x.intersect_end;
-
          /* Discard slices out of rectangle early */
          if (!iter_x.intersects)
             continue;
 
           if (iter_x.flipped)
             {
-              data.x_intersect_start = iter_x.intersect_end;
-              data.x_intersect_end = iter_x.intersect_start;
+              x_intersect_start = iter_x.intersect_end;
+              x_intersect_end = iter_x.intersect_start;
             }
 
          /* Localize slice texture coordinates */
-          slice_tx1 = data.x_intersect_start - iter_x.pos;
-          slice_tx2 = data.x_intersect_end - iter_x.pos;
+          slice_tx1 = x_intersect_start - iter_x.pos;
+          slice_tx2 = x_intersect_end - iter_x.pos;
 
           /* Normalize slice texture coordinates */
           slice_tx1 /= iter_x.span->size;
           slice_tx2 /= iter_x.span->size;
 
+          data.x_span = iter_x.span;
+
          /* Pluck out the cogl texture for this slice */
           slice_tex = g_array_index (tex_2ds->slice_textures, CoglHandle,
                                     iter_y.index * iter_x.array->len +