[gtk/wip/chergert/glproto] make bitfield go a bit further

[Christian Hergert <chergert src gnome org>]

commit c3154df7a747802e0a24ccb971a1a29c39919edf
Author: Christian Hergert <chergert redhat com>
Date:   Tue Feb 16 20:49:09 2021 -0800

    make bitfield go a bit further
    
    two more bits out of nowhere!

 gsk/next/gskgluniformstate.c        |  5 +++--
 gsk/next/gskgluniformstateprivate.h | 15 +++++++++------
 2 files changed, 12 insertions(+), 8 deletions(-)
---
diff --git a/gsk/next/gskgluniformstate.c b/gsk/next/gskgluniformstate.c
index 8bda3acf48..4422b05552 100644
--- a/gsk/next/gskgluniformstate.c
+++ b/gsk/next/gskgluniformstate.c
@@ -101,7 +101,7 @@ gsk_gl_uniform_state_init_value (GskGLUniformState        *state,
   guint offset;
 
   g_assert (state != NULL);
-  g_assert (array_count < 256);
+  g_assert (array_count < 64);
   g_assert ((int)format >= 0 && format < GSK_GL_UNIFORM_FORMAT_LAST);
   g_assert (format > 0);
   g_assert (program != NULL);
@@ -197,7 +197,8 @@ gsk_gl_uniform_state_end_frame (GskGLUniformState *state)
           /* Adjust alignment for value */
           allocator += gsk_gl_uniform_state_align (allocator, size);
 
-          info->info.offset = allocator;
+          /* Offset is in slots of 4 bytes */
+          info->info.offset = allocator / 4;
           info->info.initial = TRUE;
           info->stamp = 0;
 
diff --git a/gsk/next/gskgluniformstateprivate.h b/gsk/next/gskgluniformstateprivate.h
index 6c4f7dbd2c..db670a224f 100644
--- a/gsk/next/gskgluniformstateprivate.h
+++ b/gsk/next/gskgluniformstateprivate.h
@@ -139,7 +139,7 @@ gpointer             gsk_gl_uniform_state_init_value  (GskGLUniformState
                                                        GskGLUniformInfoElement  **infoptr);
 
 #define gsk_gl_uniform_state_get_uniform_data(state,offset) \
-  ((gconstpointer)(state->values_buf + offset))
+  ((gconstpointer)(state->values_buf + (offset*4)))
 
 #define gsk_gl_uniform_state_snapshot(state, program_info, callback, user_data) \
   G_STMT_START {                                                                \
@@ -151,7 +151,7 @@ gpointer             gsk_gl_uniform_state_init_value  (GskGLUniformState
         g_assert (location < GL_MAX_UNIFORM_LOCATIONS);                         \
         g_assert (location < program_info->n_uniforms);                         \
                                                                                 \
-        if (info->info.format > 0)                       \
+        if (info->info.format > 0)                                              \
           callback (&info->info, location, user_data);                          \
       }                                                                         \
   } G_STMT_END
@@ -182,7 +182,7 @@ gsk_gl_uniform_state_get_value (GskGLUniformState        *state,
   if G_LIKELY (format == info->info.format && array_count <= info->info.array_count)
     {
       *infoptr = info;
-      return state->values_buf + info->info.offset;
+      return state->values_buf + (info->info.offset*4);
     }
 
   return gsk_gl_uniform_state_init_value (state, program, format, array_count, location, infoptr);
@@ -215,22 +215,25 @@ gsk_gl_uniform_state_realloc (GskGLUniformState *state,
       state->values_buf = g_realloc (state->values_buf, state->values_len);
     }
 
-  *offset = state->values_pos + padding;
+  /* offsets are in slots of 4 to use fewer bits */
+  g_assert ((state->values_pos + padding) % 4 == 0);
+  *offset = (state->values_pos + padding) / 4;
   state->values_pos += padding + size;
 
-  return state->values_buf + *offset;
+  return state->values_buf + (*offset * 4);
 }
 
 #define GSK_GL_UNIFORM_STATE_REPLACE(info, u, type, count)                                \
   G_STMT_START {                                                                          \
     if ((info)->info.initial && count == (info)->info.array_count)                        \
       {                                                                                   \
-        u = (gpointer)(state->values_buf + (info)->info.offset);                          \
+        u = (gpointer)(state->values_buf + ((info)->info.offset*4));                      \
       }                                                                                   \
     else                                                                                  \
       {                                                                                   \
         guint offset;                                                                     \
         u = gsk_gl_uniform_state_realloc (state, sizeof(type) * MAX (1, count), &offset); \
+        g_assert (offset < (1 << 20));                                                    \
         (info)->info.offset = offset;                                                     \
         /* We might have increased array length */                                        \
         (info)->info.array_count = count;                                                 \