Pass rect and matrix by value in geometry functions.

Several things irk me about passing values as const pointers:

* They can be NULL, which is not a valid value.
* They require explicit temporary variables for storage.
* They don't compose easily in a legible manner, requiring
  weird pointer passing semantics where the variable being assigned
  is hidden as an argument in the innermost function call.
* We can't change the value through the pointer, requiring yet more
  local variables to hold copies of the input value.

In the device interface where we pass a matrix to a function, we often
find ourselves making a local copy of the matrix so we can concatenate
other transforms to it. This copying is a lot of unnecessary busywork
that I hope to eventually avoid by laying the groundwork with this
commit.

This is a rather large API change, so I apologize for the inconvenience,
but I hope the end result and gain in legibility will be worth the pain.

1 files changed, 2 insertions, 2 deletions

diff --git a/include/mupdf/fitz/shade.h b/include/mupdf/fitz/shade.h
index 24cb4cb2..7b821a34 100644
--- a/include/mupdf/fitz/shade.h
+++ b/include/mupdf/fitz/shade.h
@@ -115,7 +115,7 @@ void fz_drop_shade_imp(fz_context *ctx, fz_storable *shade);
 
 	Returns r, updated to contain the bounds for the shading.
 */
-fz_rect *fz_bound_shade(fz_context *ctx, fz_shade *shade, const fz_matrix *ctm, fz_rect *r);
+fz_rect fz_bound_shade(fz_context *ctx, fz_shade *shade, fz_matrix ctm);
 
 /*
 	fz_paint_shade: Render a shade to a given pixmap.
@@ -194,7 +194,7 @@ typedef void (fz_shade_process_fn)(fz_context *ctx, void *arg, fz_vertex *av, fz
 	process_arg: An opaque argument passed through from caller
 	to callback functions.
 */
-void fz_process_shade(fz_context *ctx, fz_shade *shade, const fz_matrix *ctm,
+void fz_process_shade(fz_context *ctx, fz_shade *shade, fz_matrix ctm,
 			fz_shade_prepare_fn *prepare,
 			fz_shade_process_fn *process,
 			void *process_arg);