GPU: Remove GPU_INDEX_U8

This type of indices is not natively supported on modern GPU and
gives warning on some implementation. The memory savings it
provides is also quite minimal and unlikely to be visible on
nowadays hardware.

This remove some uneeded struct members and makes primitive
restart always enabled by default. This can be broken by addons
if they are not careful enough but many other states have this
problem.

Also leverage GL_PRIMITIVE_RESTART_FIXED_INDEX if
ARB_ES3_compatibility is supported. This removes all API calls
to change restart index depending on indices length.

1 files changed, 12 insertions, 28 deletions

diff --git a/source/blender/gpu/intern/gpu_batch.c b/source/blender/gpu/intern/gpu_batch.c
index d1cfd5c337d..fb2a87fc8d1 100644
--- a/source/blender/gpu/intern/gpu_batch.c
+++ b/source/blender/gpu/intern/gpu_batch.c
@@ -545,36 +545,26 @@ void GPU_batch_uniform_mat4(GPUBatch *batch, const char *name, const float data[
   glUniformMatrix4fv(uniform->location, 1, GL_FALSE, (const float *)data);
 }
 
-static void primitive_restart_enable(const GPUIndexBuf *el)
+static void primitive_restart_index(const GPUIndexBuf *el)
 {
-  // TODO(fclem) Replace by GL_PRIMITIVE_RESTART_FIXED_INDEX when we have ogl 4.3
-  glEnable(GL_PRIMITIVE_RESTART);
-  GLuint restart_index = (GLuint)0xFFFFFFFF;
-
 #if GPU_TRACK_INDEX_RANGE
-  if (el->index_type == GPU_INDEX_U8) {
-    restart_index = (GLuint)0xFF;
-  }
-  else if (el->index_type == GPU_INDEX_U16) {
-    restart_index = (GLuint)0xFFFF;
+  /* Can be removed if GL 4.3 is available. */
+  if (!GLEW_ARB_ES3_compatibility) {
+    /* Stay sync with GPU_state_init(). */
+    static int last_type = GPU_INDEX_U32;
+    if (el->index_type != last_type) {
+      GLuint restart_index = (el->index_type == GPU_INDEX_U16) ? (GLuint)0xFFFF :
+                                                                 (GLuint)0xFFFFFFFF;
+      glPrimitiveRestartIndex(restart_index);
+    }
   }
 #endif
-
-  glPrimitiveRestartIndex(restart_index);
-}
-
-static void primitive_restart_disable(void)
-{
-  glDisable(GL_PRIMITIVE_RESTART);
 }
 
 static void *elem_offset(const GPUIndexBuf *el, int v_first)
 {
 #if GPU_TRACK_INDEX_RANGE
-  if (el->index_type == GPU_INDEX_U8) {
-    return (GLubyte *)0 + v_first;
-  }
-  else if (el->index_type == GPU_INDEX_U16) {
+  if (el->index_type == GPU_INDEX_U16) {
     return (GLushort *)0 + v_first;
   }
 #endif
@@ -641,9 +631,7 @@ void GPU_batch_draw_advanced(GPUBatch *batch, int v_first, int v_count, int i_fi
 #endif
     void *v_first_ofs = elem_offset(el, v_first);
 
-    if (el->use_prim_restart) {
-      primitive_restart_enable(el);
-    }
+    primitive_restart_index(el);
 
     if (GLEW_ARB_base_instance) {
       glDrawElementsInstancedBaseVertexBaseInstance(
@@ -653,10 +641,6 @@ void GPU_batch_draw_advanced(GPUBatch *batch, int v_first, int v_count, int i_fi
       glDrawElementsInstancedBaseVertex(
           batch->gl_prim_type, v_count, index_type, v_first_ofs, i_count, base_index);
     }
-
-    if (el->use_prim_restart) {
-      primitive_restart_disable();
-    }
   }
   else {
     if (GLEW_ARB_base_instance) {