[mutter] cogl: Remove unused explicit blend-enable controls

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit 5613f4f7f43cf2d98a15630a15992a17d25307a1
Author: Adam Jackson <ajax redhat com>
Date:   Fri Nov 1 17:07:01 2019 -0400

    cogl: Remove unused explicit blend-enable controls
    
    https://gitlab.gnome.org/GNOME/mutter/merge_requests/978

 cogl/cogl/cogl-pipeline-debug.c         | 20 +-----------
 cogl/cogl/cogl-pipeline-private.h       | 27 ---------------
 cogl/cogl/cogl-pipeline-state-private.h |  4 ---
 cogl/cogl/cogl-pipeline-state.c         | 58 ---------------------------------
 cogl/cogl/cogl-pipeline.c               | 22 +------------
 5 files changed, 2 insertions(+), 129 deletions(-)
---
diff --git a/cogl/cogl/cogl-pipeline-debug.c b/cogl/cogl/cogl-pipeline-debug.c
index 28df882bf..7555257d0 100644
--- a/cogl/cogl/cogl-pipeline-debug.c
+++ b/cogl/cogl/cogl-pipeline-debug.c
@@ -193,27 +193,9 @@ dump_pipeline_cb (CoglNode *node, void *user_data)
 
   if (pipeline->differences & COGL_PIPELINE_STATE_BLEND)
     {
-      const char *blend_enable_name;
-
       changes = TRUE;
-
-      switch (pipeline->blend_enable)
-        {
-        case COGL_PIPELINE_BLEND_ENABLE_AUTOMATIC:
-          blend_enable_name = "AUTO";
-          break;
-        case COGL_PIPELINE_BLEND_ENABLE_ENABLED:
-          blend_enable_name = "ENABLED";
-          break;
-        case COGL_PIPELINE_BLEND_ENABLE_DISABLED:
-          blend_enable_name = "DISABLED";
-          break;
-        default:
-          blend_enable_name = "UNKNOWN";
-        }
       g_string_append_printf (changes_label,
-                              "\\lblend=%s\\n",
-                              blend_enable_name);
+                              "\\lblend\\n");
     }
 
   if (pipeline->differences & COGL_PIPELINE_STATE_LAYERS)
diff --git a/cogl/cogl/cogl-pipeline-private.h b/cogl/cogl/cogl-pipeline-private.h
index 8031aa1e6..0d66a6a2b 100644
--- a/cogl/cogl/cogl-pipeline-private.h
+++ b/cogl/cogl/cogl-pipeline-private.h
@@ -62,7 +62,6 @@ typedef enum
 {
   /* sparse state */
   COGL_PIPELINE_STATE_COLOR_INDEX,
-  COGL_PIPELINE_STATE_BLEND_ENABLE_INDEX,
   COGL_PIPELINE_STATE_LAYERS_INDEX,
   COGL_PIPELINE_STATE_ALPHA_FUNC_INDEX,
   COGL_PIPELINE_STATE_ALPHA_FUNC_REFERENCE_INDEX,
@@ -99,8 +98,6 @@ typedef enum _CoglPipelineState
 {
   COGL_PIPELINE_STATE_COLOR =
     1L<<COGL_PIPELINE_STATE_COLOR_INDEX,
-  COGL_PIPELINE_STATE_BLEND_ENABLE =
-    1L<<COGL_PIPELINE_STATE_BLEND_ENABLE_INDEX,
   COGL_PIPELINE_STATE_LAYERS =
     1L<<COGL_PIPELINE_STATE_LAYERS_INDEX,
 
@@ -147,7 +144,6 @@ typedef enum _CoglPipelineState
 
 #define COGL_PIPELINE_STATE_AFFECTS_BLENDING \
   (COGL_PIPELINE_STATE_COLOR | \
-   COGL_PIPELINE_STATE_BLEND_ENABLE | \
    COGL_PIPELINE_STATE_LAYERS | \
    COGL_PIPELINE_STATE_BLEND | \
    COGL_PIPELINE_STATE_USER_SHADER | \
@@ -184,15 +180,6 @@ typedef struct
   float                        alpha_func_reference;
 } CoglPipelineAlphaFuncState;
 
-typedef enum _CoglPipelineBlendEnable
-{
-  /* XXX: we want to detect users mistakenly using TRUE or FALSE
-   * so start the enum at 2. */
-  COGL_PIPELINE_BLEND_ENABLE_ENABLED = 2,
-  COGL_PIPELINE_BLEND_ENABLE_DISABLED,
-  COGL_PIPELINE_BLEND_ENABLE_AUTOMATIC
-} CoglPipelineBlendEnable;
-
 typedef struct
 {
   /* Determines how this pipeline is blended with other primitives */
@@ -367,13 +354,6 @@ struct _CoglPipeline
   /* Determines if pipeline->big_state is valid */
   unsigned int          has_big_state:1;
 
-  /* By default blending is enabled automatically depending on the
-   * unlit color, the lighting colors or the texture format. The user
-   * can override this to explicitly enable or disable blending.
-   *
-   * This is a sparse property */
-  unsigned int          blend_enable:3;
-
   /* There are many factors that can determine if we need to enable
    * blending, this holds our final decision */
   unsigned int          real_blend_enable:1;
@@ -774,13 +754,6 @@ void
 _cogl_pipeline_apply_overrides (CoglPipeline *pipeline,
                                 CoglPipelineFlushOptions *options);
 
-CoglPipelineBlendEnable
-_cogl_pipeline_get_blend_enabled (CoglPipeline *pipeline);
-
-void
-_cogl_pipeline_set_blend_enabled (CoglPipeline *pipeline,
-                                  CoglPipelineBlendEnable enable);
-
 #ifdef COGL_DEBUG_ENABLED
 void
 _cogl_pipeline_set_static_breadcrumb (CoglPipeline *pipeline,
diff --git a/cogl/cogl/cogl-pipeline-state-private.h b/cogl/cogl/cogl-pipeline-state-private.h
index 21e1b5e55..e49fe8a45 100644
--- a/cogl/cogl/cogl-pipeline-state-private.h
+++ b/cogl/cogl/cogl-pipeline-state-private.h
@@ -108,10 +108,6 @@ void
 _cogl_pipeline_hash_color_state (CoglPipeline *authority,
                                  CoglPipelineHashState *state);
 
-void
-_cogl_pipeline_hash_blend_enable_state (CoglPipeline *authority,
-                                        CoglPipelineHashState *state);
-
 void
 _cogl_pipeline_hash_layers_state (CoglPipeline *authority,
                                   CoglPipelineHashState *state);
diff --git a/cogl/cogl/cogl-pipeline-state.c b/cogl/cogl/cogl-pipeline-state.c
index c012e45e5..ecfc4cd3b 100644
--- a/cogl/cogl/cogl-pipeline-state.c
+++ b/cogl/cogl/cogl-pipeline-state.c
@@ -407,56 +407,6 @@ cogl_pipeline_set_color4f (CoglPipeline *pipeline,
   cogl_pipeline_set_color (pipeline, &color);
 }
 
-CoglPipelineBlendEnable
-_cogl_pipeline_get_blend_enabled (CoglPipeline *pipeline)
-{
-  CoglPipeline *authority;
-
-  g_return_val_if_fail (cogl_is_pipeline (pipeline), FALSE);
-
-  authority =
-    _cogl_pipeline_get_authority (pipeline, COGL_PIPELINE_STATE_BLEND_ENABLE);
-  return authority->blend_enable;
-}
-
-static gboolean
-_cogl_pipeline_blend_enable_equal (CoglPipeline *authority0,
-                                   CoglPipeline *authority1)
-{
-  return authority0->blend_enable == authority1->blend_enable ? TRUE : FALSE;
-}
-
-void
-_cogl_pipeline_set_blend_enabled (CoglPipeline *pipeline,
-                                  CoglPipelineBlendEnable enable)
-{
-  CoglPipelineState state = COGL_PIPELINE_STATE_BLEND_ENABLE;
-  CoglPipeline *authority;
-
-  g_return_if_fail (cogl_is_pipeline (pipeline));
-  g_return_if_fail (enable > 1 &&
-                    "don't pass TRUE or FALSE to _set_blend_enabled!");
-
-  authority = _cogl_pipeline_get_authority (pipeline, state);
-
-  if (authority->blend_enable == enable)
-    return;
-
-  /* - Flush journal primitives referencing the current state.
-   * - Make sure the pipeline has no dependants so it may be modified.
-   * - If the pipeline isn't currently an authority for the state being
-   *   changed, then initialize that state from the current authority.
-   */
-  _cogl_pipeline_pre_change_notify (pipeline, state, NULL, FALSE);
-
-  pipeline->blend_enable = enable;
-
-  _cogl_pipeline_update_authority (pipeline, authority, state,
-                                   _cogl_pipeline_blend_enable_equal);
-
-  pipeline->dirty_real_blend_enable = TRUE;
-}
-
 static void
 _cogl_pipeline_set_alpha_test_function (CoglPipeline *pipeline,
                                         CoglPipelineAlphaFunc alpha_func)
@@ -1379,14 +1329,6 @@ _cogl_pipeline_hash_color_state (CoglPipeline *authority,
                                                _COGL_COLOR_DATA_SIZE);
 }
 
-void
-_cogl_pipeline_hash_blend_enable_state (CoglPipeline *authority,
-                                        CoglPipelineHashState *state)
-{
-  uint8_t blend_enable = authority->blend_enable;
-  state->hash = _cogl_util_one_at_a_time_hash (state->hash, &blend_enable, 1);
-}
-
 void
 _cogl_pipeline_hash_alpha_func_state (CoglPipeline *authority,
                                       CoglPipelineHashState *state)
diff --git a/cogl/cogl/cogl-pipeline.c b/cogl/cogl/cogl-pipeline.c
index 51f5b005e..afbac1bb8 100644
--- a/cogl/cogl/cogl-pipeline.c
+++ b/cogl/cogl/cogl-pipeline.c
@@ -104,7 +104,6 @@ _cogl_pipeline_init_default_pipeline (void)
 
   pipeline->real_blend_enable = FALSE;
 
-  pipeline->blend_enable = COGL_PIPELINE_BLEND_ENABLE_AUTOMATIC;
   pipeline->layer_differences = NULL;
   pipeline->n_layers = 0;
 
@@ -721,24 +720,12 @@ _cogl_pipeline_needs_blending_enabled (CoglPipeline *pipeline,
                                        const CoglColor *override_color,
                                        gboolean unknown_color_alpha)
 {
-  CoglPipeline *enable_authority;
   CoglPipeline *blend_authority;
   CoglPipelineBlendState *blend_state;
-  CoglPipelineBlendEnable enabled;
 
   if (G_UNLIKELY (COGL_DEBUG_ENABLED (COGL_DEBUG_DISABLE_BLENDING)))
     return FALSE;
 
-  /* We unconditionally check the _BLEND_ENABLE state first because
-   * all the other changes are irrelevent if blend_enable != _AUTOMATIC
-   */
-  enable_authority =
-    _cogl_pipeline_get_authority (pipeline, COGL_PIPELINE_STATE_BLEND_ENABLE);
-
-  enabled = enable_authority->blend_enable;
-  if (enabled != COGL_PIPELINE_BLEND_ENABLE_AUTOMATIC)
-    return enabled == COGL_PIPELINE_BLEND_ENABLE_ENABLED ? TRUE : FALSE;
-
   blend_authority =
     _cogl_pipeline_get_authority (pipeline, COGL_PIPELINE_STATE_BLEND);
 
@@ -826,9 +813,6 @@ _cogl_pipeline_copy_differences (CoglPipeline *dest,
   if (differences & COGL_PIPELINE_STATE_COLOR)
     dest->color = src->color;
 
-  if (differences & COGL_PIPELINE_STATE_BLEND_ENABLE)
-    dest->blend_enable = src->blend_enable;
-
   if (differences & COGL_PIPELINE_STATE_LAYERS)
     {
       GList *l;
@@ -977,7 +961,6 @@ _cogl_pipeline_init_multi_property_sparse_state (CoglPipeline *pipeline,
     /* XXX: avoid using a default: label so we get a warning if we
      * don't explicitly handle a newly defined state-group here. */
     case COGL_PIPELINE_STATE_COLOR:
-    case COGL_PIPELINE_STATE_BLEND_ENABLE:
     case COGL_PIPELINE_STATE_ALPHA_FUNC:
     case COGL_PIPELINE_STATE_ALPHA_FUNC_REFERENCE:
     case COGL_PIPELINE_STATE_NON_ZERO_POINT_SIZE:
@@ -2170,7 +2153,6 @@ _cogl_pipeline_equal (CoglPipeline *pipeline0,
             break;
           }
 
-        case COGL_PIPELINE_STATE_BLEND_ENABLE_INDEX:
         case COGL_PIPELINE_STATE_REAL_BLEND_ENABLE_INDEX:
         case COGL_PIPELINE_STATE_COUNT:
           g_warn_if_reached ();
@@ -2514,8 +2496,6 @@ _cogl_pipeline_init_state_hash_functions (void)
 {
   state_hash_functions[COGL_PIPELINE_STATE_COLOR_INDEX] =
     _cogl_pipeline_hash_color_state;
-  state_hash_functions[COGL_PIPELINE_STATE_BLEND_ENABLE_INDEX] =
-    _cogl_pipeline_hash_blend_enable_state;
   state_hash_functions[COGL_PIPELINE_STATE_LAYERS_INDEX] =
     _cogl_pipeline_hash_layers_state;
   state_hash_functions[COGL_PIPELINE_STATE_ALPHA_FUNC_INDEX] =
@@ -2545,7 +2525,7 @@ _cogl_pipeline_init_state_hash_functions (void)
 
   {
   /* So we get a big error if we forget to update this code! */
-  _COGL_STATIC_ASSERT (COGL_PIPELINE_STATE_SPARSE_COUNT == 15,
+  _COGL_STATIC_ASSERT (COGL_PIPELINE_STATE_SPARSE_COUNT == 14,
                        "Make sure to install a hash function for "
                        "newly added pipeline state and update assert "
                        "in _cogl_pipeline_init_state_hash_functions");