[gegl] transform: don't combine transform ops with different near-z values

[N/A <ell src gnome org>]

commit f9c9e6e7eeb1b3401f6846d48ae4f1a51d39ad65
Author: Ell <ell_se yahoo com>
Date:   Thu Mar 22 16:36:01 2018 -0400

    transform: don't combine transform ops with different near-z values
    
    Avoid combining consecutive transform ops when their near-z values
    are different, instead of taking the maximal value, which is not
    generally equivalent.  Note that under certain conditions we could
    still combine such ops, but we currently never do.

 operations/transform/transform-core.c |   70 +++++++++++----------------------
 1 files changed, 23 insertions(+), 47 deletions(-)
---
diff --git a/operations/transform/transform-core.c b/operations/transform/transform-core.c
index 02bafc3..42a33c8 100644
--- a/operations/transform/transform-core.c
+++ b/operations/transform/transform-core.c
@@ -80,8 +80,7 @@ static gboolean      gegl_transform_scanline_limits              (const GeglMatr
 static gboolean      gegl_transform_is_intermediate_node         (OpTransform          *transform);
 static gboolean      gegl_transform_is_composite_node            (OpTransform          *transform);
 static void          gegl_transform_get_source_matrix            (OpTransform          *transform,
-                                                                  GeglMatrix3          *output,
-                                                                  gdouble              *near_z);
+                                                                  GeglMatrix3          *output);
 static GeglRectangle gegl_transform_get_bounding_box             (GeglOperation        *op);
 static GeglRectangle gegl_transform_get_invalidated_by_change    (GeglOperation        *operation,
                                                                   const gchar          *input_pad,
@@ -101,8 +100,7 @@ static GeglNode     *gegl_transform_detect                       (GeglOperation
 static gboolean      gegl_matrix3_is_affine                      (GeglMatrix3          *matrix);
 static gboolean      gegl_transform_matrix3_allow_fast_translate (GeglMatrix3          *matrix);
 static void          gegl_transform_create_composite_matrix      (OpTransform          *transform,
-                                                                  GeglMatrix3          *matrix,
-                                                                  gdouble              *near_z);
+                                                                  GeglMatrix3          *matrix);
 
 /* ************************* */
 
@@ -303,27 +301,19 @@ gegl_transform_create_matrix (OpTransform *transform,
 
 static void
 gegl_transform_create_composite_matrix (OpTransform *transform,
-                                        GeglMatrix3 *matrix,
-                                        gdouble     *near_z)
+                                        GeglMatrix3 *matrix)
 {
   gegl_transform_create_matrix (transform, matrix);
 
   if (transform->origin_x || transform->origin_y)
     gegl_matrix3_originate (matrix, transform->origin_x, transform->origin_y);
 
-  if (near_z)
-    *near_z = transform->near_z;
-
   if (gegl_transform_is_composite_node (transform))
     {
       GeglMatrix3 source;
-      gdouble     source_near_z;
 
-      gegl_transform_get_source_matrix (transform, &source, &source_near_z);
+      gegl_transform_get_source_matrix (transform, &source);
       gegl_matrix3_multiply (matrix, &source, matrix);
-
-      if (near_z)
-        *near_z = MAX (*near_z, source_near_z);
     }
 }
 
@@ -672,10 +662,11 @@ gegl_transform_is_intermediate_node (OpTransform *transform)
         {
           GeglOperation *sink = gegl_node_get_gegl_operation (consumers[i]);
 
-          if (! IS_OP_TRANSFORM (sink)                           ||
-              transform->sampler != OP_TRANSFORM (sink)->sampler ||
+          if (! IS_OP_TRANSFORM (sink)                              ||
+              transform->sampler != OP_TRANSFORM (sink)->sampler    ||
               gegl_transform_get_abyss_policy (transform) !=
-              gegl_transform_get_abyss_policy (OP_TRANSFORM (sink)))
+              gegl_transform_get_abyss_policy (OP_TRANSFORM (sink)) ||
+              transform->near_z != OP_TRANSFORM (sink)->near_z)
             {
               is_intermediate = FALSE;
               break;
@@ -708,8 +699,7 @@ gegl_transform_is_composite_node (OpTransform *transform)
 
 static void
 gegl_transform_get_source_matrix (OpTransform *transform,
-                                  GeglMatrix3 *output,
-                                  gdouble     *near_z)
+                                  GeglMatrix3 *output)
 {
   GeglOperation *op = GEGL_OPERATION (transform);
   GeglNode *source_node;
@@ -722,7 +712,7 @@ gegl_transform_get_source_matrix (OpTransform *transform,
   source = gegl_node_get_gegl_operation (source_node);
   g_assert (IS_OP_TRANSFORM (source));
 
-  gegl_transform_create_composite_matrix (OP_TRANSFORM (source), output, near_z);
+  gegl_transform_create_composite_matrix (OP_TRANSFORM (source), output);
   /*gegl_matrix3_copy (output, OP_TRANSFORM (source)->matrix);*/
 }
 
@@ -731,7 +721,6 @@ gegl_transform_get_bounding_box (GeglOperation *op)
 {
   OpTransform  *transform = OP_TRANSFORM (op);
   GeglMatrix3   matrix;
-  gdouble       near_z;
   GeglRectangle in_rect   = {0,0,0,0},
                 have_rect = {0,0,0,0};
   gdouble       vertices [8];
@@ -756,7 +745,7 @@ gegl_transform_get_bounding_box (GeglOperation *op)
       gegl_rectangle_is_infinite_plane (&in_rect))
     return in_rect;
 
-  gegl_transform_create_composite_matrix (transform, &matrix, &near_z);
+  gegl_transform_create_composite_matrix (transform, &matrix);
 
   if (gegl_transform_is_intermediate_node (transform) ||
       gegl_matrix3_is_identity (&matrix))
@@ -785,8 +774,8 @@ gegl_transform_get_bounding_box (GeglOperation *op)
   /*
    * Clip polygon to the near plane.
    */
-  n_have_points = gegl_transform_depth_clip (&matrix, near_z, vertices, 4,
-                                             have_points);
+  n_have_points = gegl_transform_depth_clip (&matrix, transform->near_z,
+                                             vertices, 4, have_points);
 
   if (n_have_points > 1)
     {
@@ -862,7 +851,6 @@ gegl_transform_get_required_for_output (GeglOperation       *op,
 {
   OpTransform   *transform = OP_TRANSFORM (op);
   GeglMatrix3    inverse;
-  gdouble        near_z;
   GeglRectangle  requested_rect,
                  need_rect = {};
   GeglRectangle  context_rect;
@@ -880,7 +868,7 @@ gegl_transform_get_required_for_output (GeglOperation       *op,
       gegl_rectangle_is_infinite_plane (&requested_rect))
     return requested_rect;
 
-  gegl_transform_create_composite_matrix (transform, &inverse, &near_z);
+  gegl_transform_create_composite_matrix (transform, &inverse);
   gegl_matrix3_invert (&inverse);
 
   if (gegl_transform_is_intermediate_node (transform) ||
@@ -918,7 +906,7 @@ gegl_transform_get_required_for_output (GeglOperation       *op,
   /*
    * Clip polygon to the near plane.
    */
-  n_need_points = gegl_transform_depth_clip (&inverse, 1.0 / near_z,
+  n_need_points = gegl_transform_depth_clip (&inverse, 1.0 / transform->near_z,
                                              temp_points, n_temp_points,
                                              need_points);
 
@@ -955,7 +943,6 @@ gegl_transform_get_invalidated_by_change (GeglOperation       *op,
 {
   OpTransform   *transform = OP_TRANSFORM (op);
   GeglMatrix3    matrix;
-  gdouble        near_z;
   GeglRectangle  affected_rect = {};
 
   GeglRectangle  context_rect;
@@ -1009,7 +996,7 @@ gegl_transform_get_invalidated_by_change (GeglOperation       *op,
   context_rect = *gegl_sampler_get_context_rect (sampler);
   g_object_unref (sampler);
 
-  gegl_transform_create_composite_matrix (transform, &matrix, &near_z);
+  gegl_transform_create_composite_matrix (transform, &matrix);
 
   if (gegl_transform_is_intermediate_node (transform) ||
       gegl_matrix3_is_identity (&matrix))
@@ -1045,8 +1032,8 @@ gegl_transform_get_invalidated_by_change (GeglOperation       *op,
   /*
    * Clip polygon to the near plane.
    */
-  n_affected_points = gegl_transform_depth_clip (&matrix, near_z, vertices, 4,
-                                                 affected_points);
+  n_affected_points = gegl_transform_depth_clip (&matrix, transform->near_z,
+                                                 vertices, 4, affected_points);
 
   if (n_affected_points > 1)
     {
@@ -1068,7 +1055,6 @@ typedef struct ThreadData
                 GeglBuffer          *dest,
                 GeglBuffer          *src,
                 GeglMatrix3         *matrix,
-                gdouble              near_z,
                 const GeglRectangle *roi,
                 gint                 level);
 
@@ -1078,7 +1064,6 @@ typedef struct ThreadData
   GeglBuffer               *output;
   gint                     *pending;
   GeglMatrix3              *matrix;
-  gdouble                   near_z;
   gint                      level;
   gboolean                  success;
   GeglRectangle             roi;
@@ -1098,7 +1083,6 @@ static void thread_process (gpointer thread_data, gpointer input)
               data->output,
               input,
               data->matrix,
-              data->near_z,
               &data->roi,
               data->level);
 
@@ -1124,7 +1108,6 @@ transform_affine (GeglOperation       *operation,
                   GeglBuffer          *dest,
                   GeglBuffer          *src,
                   GeglMatrix3         *matrix,
-                  gdouble              near_z,
                   const GeglRectangle *roi,
                   gint                 level)
 {
@@ -1132,7 +1115,7 @@ transform_affine (GeglOperation       *operation,
   OpTransform     *transform = (OpTransform *) operation;
   const Babl      *format = babl_format ("RaGaBaA float");
   GeglMatrix3      inverse;
-  gdouble          inverse_near_z = 1.0 / near_z;
+  gdouble          inverse_near_z = 1.0 / transform->near_z;
   GeglMatrix2      inverse_jacobian;
   GeglAbyssPolicy  abyss_policy = gegl_transform_get_abyss_policy (transform);
   GeglSampler     *sampler = gegl_buffer_sampler_new_at_level (src,
@@ -1280,7 +1263,6 @@ transform_generic (GeglOperation       *operation,
                    GeglBuffer          *dest,
                    GeglBuffer          *src,
                    GeglMatrix3         *matrix,
-                   gdouble              near_z,
                    const GeglRectangle *roi,
                    gint                 level)
 {
@@ -1289,7 +1271,7 @@ transform_generic (GeglOperation       *operation,
   gint                 factor = 1 << level;
   GeglBufferIterator  *i;
   GeglMatrix3          inverse;
-  gdouble              inverse_near_z = 1.0 / near_z;
+  gdouble              inverse_near_z = 1.0 / transform->near_z;
   GeglAbyssPolicy      abyss_policy = gegl_transform_get_abyss_policy (transform);
   GeglSampler *sampler = gegl_buffer_sampler_new_at_level (src,
                                          babl_format("RaGaBaA float"),
@@ -1434,7 +1416,6 @@ transform_nearest (GeglOperation       *operation,
                    GeglBuffer          *dest,
                    GeglBuffer          *src,
                    GeglMatrix3         *matrix,
-                   gdouble              near_z,
                    const GeglRectangle *roi,
                    gint                 level)
 {
@@ -1444,7 +1425,7 @@ transform_nearest (GeglOperation       *operation,
   gint                 px_size   = babl_format_get_bytes_per_pixel (format);
   GeglBufferIterator  *i;
   GeglMatrix3          inverse;
-  gdouble              inverse_near_z = 1.0 / near_z;
+  gdouble              inverse_near_z = 1.0 / transform->near_z;
   GeglAbyssPolicy      abyss_policy = gegl_transform_get_abyss_policy (transform);
   GeglSampler *sampler = gegl_buffer_sampler_new_at_level (src, format,
                                          GEGL_SAMPLER_NEAREST,
@@ -1483,8 +1464,6 @@ transform_nearest (GeglOperation       *operation,
 
   gegl_matrix3_invert (&inverse);
 
-  near_z = 1.0 / near_z;
-
   /*
    * Fill the output tiles.
    */
@@ -1618,10 +1597,9 @@ gegl_transform_process (GeglOperation        *operation,
   GeglBuffer  *input;
   GeglBuffer  *output;
   GeglMatrix3  matrix;
-  gdouble      near_z;
   OpTransform *transform = (OpTransform *) operation;
 
-  gegl_transform_create_composite_matrix (transform, &matrix, &near_z);
+  gegl_transform_create_composite_matrix (transform, &matrix);
 
   if (gegl_transform_is_intermediate_node (transform) ||
       gegl_matrix3_is_identity (&matrix))
@@ -1675,7 +1653,6 @@ gegl_transform_process (GeglOperation        *operation,
                     GeglBuffer          *dest,
                     GeglBuffer          *src,
                     GeglMatrix3         *matrix,
-                    gdouble              near_z,
                     const GeglRectangle *roi,
                     gint                 level) = transform_generic;
 
@@ -1729,7 +1706,6 @@ gegl_transform_process (GeglOperation        *operation,
         {
           thread_data[i].func = func;
           thread_data[i].matrix = &matrix;
-          thread_data[i].near_z = near_z;
           thread_data[i].operation = operation;
           thread_data[i].context = context;
           thread_data[i].output = output;
@@ -1746,7 +1722,7 @@ gegl_transform_process (GeglOperation        *operation,
       }
       else
       {
-        func (operation, output, input, &matrix, near_z, result, level);
+        func (operation, output, input, &matrix, result, level);
       }
 
       g_clear_object (&input);