[gtk/wip/chergert/glproto: 890/920] avoid walking gaps in location mapping array

[Christian Hergert <chergert src gnome org>]

commit 9ffb490c71f335e6d8b37bd0cd8328167e6335e7
Author: Christian Hergert <chergert redhat com>
Date:   Wed Feb 3 16:57:40 2021 -0800

    avoid walking gaps in location mapping array

 gsk/next/gskgluniformstate.c        | 59 ++++++++++++++++++++++++-------------
 gsk/next/gskgluniformstateprivate.h | 24 ++++++++++-----
 2 files changed, 54 insertions(+), 29 deletions(-)
---
diff --git a/gsk/next/gskgluniformstate.c b/gsk/next/gskgluniformstate.c
index 6cf8ccf541..1682ebdabe 100644
--- a/gsk/next/gskgluniformstate.c
+++ b/gsk/next/gskgluniformstate.c
@@ -101,6 +101,15 @@ rounded_rect_equal (const GskRoundedRect *r1,
   return memcmp (r1, r2, sizeof *r1) == 0;
 }
 
+static void
+clear_program_info (gpointer data)
+{
+  GskGLUniformProgram *program_info = data;
+
+  g_clear_pointer (&program_info->uniform_info, g_array_unref);
+  g_clear_pointer (&program_info->changed, g_array_unref);
+}
+
 GskGLUniformState *
 gsk_gl_uniform_state_new (void)
 {
@@ -112,6 +121,8 @@ gsk_gl_uniform_state_new (void)
   state->values_pos = 0;
   state->values_buf = g_malloc (4096);
 
+  g_array_set_clear_func (state->program_info, clear_program_info);
+
   return g_steal_pointer (&state);
 }
 
@@ -139,16 +150,19 @@ gsk_gl_uniform_state_unref (GskGLUniformState *state)
 static inline void
 program_changed (GskGLUniformState *state,
                  GskGLUniformInfo  *info,
-                 guint              program)
+                 guint              program,
+                 guint              location)
 {
   if (info->changed == FALSE)
     {
+      const GskGLUniformProgram *program_info = &g_array_index (state->program_info, GskGLUniformProgram, 
program);
+
       g_assert (program < state->program_info->len);
 
       info->changed = TRUE;
       info->initial = FALSE;
 
-      g_array_index (state->program_info, GskGLUniformProgram, program).n_changed++;
+      g_array_append_val (program_info->changed, location);
     }
 }
 
@@ -164,7 +178,8 @@ gsk_gl_uniform_state_clear_program (GskGLUniformState *state,
     return;
 
   program_info = &g_array_index (state->program_info, GskGLUniformProgram, program);
-  program_info->n_changed = 0;
+
+  g_clear_pointer (&program_info->changed, g_array_unref);
   g_clear_pointer (&program_info->uniform_info, g_array_unref);
 }
 
@@ -275,7 +290,7 @@ setup_info:
 
       program_info = &g_array_index (state->program_info, GskGLUniformProgram, program);
       program_info->uniform_info = g_array_new (FALSE, TRUE, sizeof (GskGLUniformInfo));
-      program_info->n_changed = 0;
+      program_info->changed = g_array_new (FALSE, FALSE, sizeof (guint));
     }
 
   g_assert (program_info != NULL);
@@ -325,7 +340,7 @@ gsk_gl_uniform_state_set1f (GskGLUniformState *state,
         {
           REPLACE_UNIFORM (info, u, GSK_GL_UNIFORM_FORMAT_1F, 1);
           u->v0 = value0;
-          program_changed (state, info, program);
+          program_changed (state, info, program, location);
         }
     }
 }
@@ -350,7 +365,7 @@ gsk_gl_uniform_state_set2f (GskGLUniformState *state,
           REPLACE_UNIFORM (info, u, GSK_GL_UNIFORM_FORMAT_2F, 1);
           u->v0 = value0;
           u->v1 = value1;
-          program_changed (state, info, program);
+          program_changed (state, info, program, location);
         }
     }
 }
@@ -377,7 +392,7 @@ gsk_gl_uniform_state_set3f (GskGLUniformState *state,
           u->v0 = value0;
           u->v1 = value1;
           u->v2 = value2;
-          program_changed (state, info, program);
+          program_changed (state, info, program, location);
         }
     }
 }
@@ -406,7 +421,7 @@ gsk_gl_uniform_state_set4f (GskGLUniformState *state,
           u->v1 = value1;
           u->v2 = value2;
           u->v3 = value3;
-          program_changed (state, info, program);
+          program_changed (state, info, program, location);
         }
     }
 }
@@ -429,7 +444,7 @@ gsk_gl_uniform_state_set1ui (GskGLUniformState *state,
         {
           REPLACE_UNIFORM (info, u, GSK_GL_UNIFORM_FORMAT_1UI, 1);
           u->v0 = value0;
-          program_changed (state, info, program);
+          program_changed (state, info, program, location);
         }
     }
 }
@@ -452,7 +467,7 @@ gsk_gl_uniform_state_set1i (GskGLUniformState *state,
         {
           REPLACE_UNIFORM (info, u, GSK_GL_UNIFORM_FORMAT_1I, 1);
           u->v0 = value0;
-          program_changed (state, info, program);
+          program_changed (state, info, program, location);
         }
     }
 }
@@ -477,7 +492,7 @@ gsk_gl_uniform_state_set2i (GskGLUniformState *state,
           REPLACE_UNIFORM (info, u, GSK_GL_UNIFORM_FORMAT_2I, 1);
           u->v0 = value0;
           u->v1 = value1;
-          program_changed (state, info, program);
+          program_changed (state, info, program, location);
         }
     }
 }
@@ -504,7 +519,7 @@ gsk_gl_uniform_state_set3i (GskGLUniformState *state,
           u->v0 = value0;
           u->v1 = value1;
           u->v2 = value2;
-          program_changed (state, info, program);
+          program_changed (state, info, program, location);
         }
     }
 }
@@ -533,7 +548,7 @@ gsk_gl_uniform_state_set4i (GskGLUniformState *state,
           u->v1 = value1;
           u->v2 = value2;
           u->v3 = value3;
-          program_changed (state, info, program);
+          program_changed (state, info, program, location);
         }
     }
 }
@@ -571,7 +586,7 @@ gsk_gl_uniform_state_set_rounded_rect (GskGLUniformState    *state,
           REPLACE_UNIFORM (info, u, GSK_GL_UNIFORM_FORMAT_ROUNDED_RECT, 1);
 
           memcpy (u, rounded_rect, sizeof *rounded_rect);
-          program_changed (state, info, program);
+          program_changed (state, info, program, location);
         }
     }
 }
@@ -600,7 +615,7 @@ gsk_gl_uniform_state_set_matrix (GskGLUniformState       *state,
 
       REPLACE_UNIFORM (info, u, GSK_GL_UNIFORM_FORMAT_MATRIX, 1);
       memcpy (u, matrix, sizeof *matrix);
-      program_changed (state, info, program);
+      program_changed (state, info, program, location);
     }
 }
 
@@ -638,7 +653,7 @@ gsk_gl_uniform_state_set_texture (GskGLUniformState *state,
         {
           REPLACE_UNIFORM (info, u, GSK_GL_UNIFORM_FORMAT_TEXTURE, 1);
           *u = texture_slot;
-          program_changed (state, info, program);
+          program_changed (state, info, program, location);
         }
     }
 }
@@ -676,7 +691,7 @@ gsk_gl_uniform_state_set_color (GskGLUniformState *state,
         {
           REPLACE_UNIFORM (info, u, GSK_GL_UNIFORM_FORMAT_COLOR, 1);
           memcpy (u, color, sizeof *color);
-          program_changed (state, info, program);
+          program_changed (state, info, program, location);
         }
     }
 }
@@ -703,7 +718,7 @@ gsk_gl_uniform_state_set1fv (GskGLUniformState *state,
         {
           REPLACE_UNIFORM (info, u, GSK_GL_UNIFORM_FORMAT_1FV, count);
           memcpy (u, value, sizeof (Uniform1f) * count);
-          program_changed (state, info, program);
+          program_changed (state, info, program, location);
         }
     }
 }
@@ -730,7 +745,7 @@ gsk_gl_uniform_state_set2fv (GskGLUniformState *state,
         {
           REPLACE_UNIFORM (info, u, GSK_GL_UNIFORM_FORMAT_2FV, count);
           memcpy (u, value, sizeof (Uniform2f) * count);
-          program_changed (state, info, program);
+          program_changed (state, info, program, location);
         }
     }
 }
@@ -757,7 +772,7 @@ gsk_gl_uniform_state_set3fv (GskGLUniformState *state,
         {
           REPLACE_UNIFORM (info, u, GSK_GL_UNIFORM_FORMAT_3FV, count);
           memcpy (u, value, sizeof (Uniform3f) * count);
-          program_changed (state, info, program);
+          program_changed (state, info, program, location);
         }
     }
 }
@@ -784,7 +799,7 @@ gsk_gl_uniform_state_set4fv (GskGLUniformState *state,
         {
           REPLACE_UNIFORM (info, u, GSK_GL_UNIFORM_FORMAT_4FV, count);
           memcpy (u, value, sizeof (Uniform4f) * count);
-          program_changed (state, info, program);
+          program_changed (state, info, program, location);
         }
     }
 }
@@ -831,6 +846,8 @@ gsk_gl_uniform_state_end_frame (GskGLUniformState *state)
           /* Now advance for this items data */
           allocator += size;
         }
+
+      program_info->changed->len = 0;
     }
 
   state->values_pos = allocator;
diff --git a/gsk/next/gskgluniformstateprivate.h b/gsk/next/gskgluniformstateprivate.h
index aeaf8399aa..b95a87e97e 100644
--- a/gsk/next/gskgluniformstateprivate.h
+++ b/gsk/next/gskgluniformstateprivate.h
@@ -27,8 +27,14 @@ G_BEGIN_DECLS
 
 typedef struct _GskGLUniformProgram
 {
+  /* Array of GskGLUniformInfo, index is GLSL location */
   GArray *uniform_info;
-  guint   n_changed;
+
+  /* To avoid walking unchanged locations in @uniform_info (or sparse
+   * elements used to map location->info), we use this to determine the
+   * specific uniforms that changed this frame.
+   */
+  GArray *changed;
 } GskGLUniformProgram;
 
 typedef struct _GskGLUniformState
@@ -205,23 +211,25 @@ gsk_gl_uniform_state_get_uniform_data (const GskGLUniformState *state,
       break;                                                                                       \
                                                                                                    \
     program_info = &g_array_index (state->program_info, GskGLUniformProgram, program_id);          \
-    if (program_info->n_changed == 0)                                                              \
+    if (program_info->changed->len == 0)                                                           \
       break;                                                                                       \
                                                                                                    \
-    for (guint i = 0; i < program_info->uniform_info->len; i++)                                    \
+    for (guint z = 0; z < program_info->changed->len; z++)                                         \
       {                                                                                            \
-        GskGLUniformInfo *info = &g_array_index (program_info->uniform_info, GskGLUniformInfo, i); \
+        guint location = g_array_index (program_info->changed, guint, z);                          \
+        GskGLUniformInfo *info = &g_array_index (program_info->uniform_info,                       \
+                                                 GskGLUniformInfo,                                 \
+                                                 location);                                        \
                                                                                                    \
-        if (!info->changed)                                                                        \
-          continue;                                                                                \
+        g_assert (info->changed);                                                                  \
                                                                                                    \
-        callback (info, i, user_data);                                                             \
+        callback (info, location, user_data);                                                      \
                                                                                                    \
         info->changed = FALSE;                                                                     \
         info->send_corners = FALSE;                                                                \
       }                                                                                            \
                                                                                                    \
-    program_info->n_changed = 0;                                                                   \
+    program_info->changed->len = 0;                                                                \
   } G_STMT_END
 
 G_END_DECLS