From edb83e306bda8a78a8a72006f257922cda7adc69 Mon Sep 17 00:00:00 2001
From: Carl Worth <cworth@cworth.org>
Date: Fri, 24 Mar 2006 12:07:21 -0800
Subject: [PATCH] cairo-ps-surface: Simplify operation analysis.

Introduce a new pattern_operation_analyze function which allows a much
simpler idiom to be used by all of the drawing operations. This also
provides new assertions that when we are not analyzing we are never
called to perform an operation that we would analyze as
unsupported.
---
 src/cairo-ps-surface.c | 57 ++++++++++++++++++++++++++----------------
 1 file changed, 35 insertions(+), 22 deletions(-)

diff --git a/src/cairo-ps-surface.c b/src/cairo-ps-surface.c
index f90a9c83f..305240a10 100644
--- a/src/cairo-ps-surface.c
+++ b/src/cairo-ps-surface.c
@@ -644,7 +644,7 @@ pattern_supported (const cairo_pattern_t *pattern)
 
 static cairo_bool_t
 pattern_operation_supported (cairo_operator_t op,
-				  const cairo_pattern_t *pattern)
+			     const cairo_pattern_t *pattern)
 {
     if (! pattern_supported (pattern))
 	return FALSE;
@@ -655,6 +655,16 @@ pattern_operation_supported (cairo_operator_t op,
     return pattern_is_opaque (pattern);
 }
 
+static cairo_int_status_t
+pattern_operation_analyze (cairo_operator_t op,
+			   const cairo_pattern_t *pattern)
+{
+    if (pattern_operation_supported (op, pattern))
+	return CAIRO_STATUS_SUCCESS;
+    else
+	return CAIRO_INT_STATUS_UNSUPPORTED;
+}
+
 /* PS Output - this section handles output of the parts of the meta
  * surface we can render natively in PS. */
 
@@ -1132,11 +1142,18 @@ _cairo_ps_surface_paint (void			*abstract_surface,
     cairo_output_stream_t *stream = surface->stream;
     cairo_ps_surface_path_info_t info;
 
-    if (surface->paginated_mode == CAIRO_PAGINATED_MODE_ANALYZE) {
-	if (!pattern_operation_supported (op, source))
-	    return CAIRO_INT_STATUS_UNSUPPORTED;
-	return CAIRO_STATUS_SUCCESS;
-    }
+    if (surface->paginated_mode == CAIRO_PAGINATED_MODE_ANALYZE)
+	return pattern_operation_analyze (op, source);
+
+    /* XXX: It would be nice to be able to assert this condition
+     * here. But, we actually allow one 'cheat' that is used when
+     * painting the final image-based fallbacks. The final fallbacks
+     * do have alpha which we support by blending with white. This is
+     * possible only because there is nothing between the fallback
+     * images and the paper, nor is anything painted above. */
+    /*
+    assert (pattern_operation_supported (op, source));
+    */
     
     if (surface->need_start_page)
 	_cairo_ps_surface_start_page (surface);
@@ -1206,12 +1223,10 @@ _cairo_ps_surface_stroke (void			*abstract_surface,
     cairo_int_status_t status;
     cairo_ps_surface_path_info_t info;
 
-    if (surface->paginated_mode == CAIRO_PAGINATED_MODE_ANALYZE) {
-	if (!pattern_operation_supported (op, source))
-	    return CAIRO_INT_STATUS_UNSUPPORTED;
-    
-	return CAIRO_STATUS_SUCCESS;
-    }
+    if (surface->paginated_mode == CAIRO_PAGINATED_MODE_ANALYZE)
+	return pattern_operation_analyze (op, source);
+
+    assert (pattern_operation_supported (op, source));
     
     if (surface->need_start_page)
 	_cairo_ps_surface_start_page (surface);
@@ -1284,11 +1299,10 @@ _cairo_ps_surface_fill (void		*abstract_surface,
     cairo_ps_surface_path_info_t info;
     const char *ps_operator;
 
-    if (surface->paginated_mode == CAIRO_PAGINATED_MODE_ANALYZE) {
-	if (!pattern_operation_supported (op, source))
-	    return CAIRO_INT_STATUS_UNSUPPORTED;
-	return CAIRO_STATUS_SUCCESS;
-    }
+    if (surface->paginated_mode == CAIRO_PAGINATED_MODE_ANALYZE)
+	return pattern_operation_analyze (op, source);
+
+    assert (pattern_operation_supported (op, source));
     
     if (surface->need_start_page)
 	_cairo_ps_surface_start_page (surface);
@@ -1339,11 +1353,10 @@ _cairo_ps_surface_show_glyphs (void		     *abstract_surface,
     cairo_int_status_t status;
     cairo_path_fixed_t *path;
 
-    if (surface->paginated_mode == CAIRO_PAGINATED_MODE_ANALYZE) {
-	if (!pattern_operation_supported (op, source))
-	    return CAIRO_INT_STATUS_UNSUPPORTED;
-	return CAIRO_STATUS_SUCCESS;
-    }
+    if (surface->paginated_mode == CAIRO_PAGINATED_MODE_ANALYZE)
+	return pattern_operation_analyze (op, source);
+
+    assert (pattern_operation_supported (op, source));
 
     if (surface->need_start_page)
 	_cairo_ps_surface_start_page (surface);