[Bf-blender-cvs] [75c6119dc91] blender2.8: Fix: GWN Indexbuf creation was replacing the index buff bound to the last VAO

[Germano]

Commit: 75c6119dc919d9769ef699c833a01b10ba01b75a
Author: Germano
Date:   Wed Mar 21 11:55:38 2018 -0300
Branches: blender2.8
https://developer.blender.org/rB75c6119dc919d9769ef699c833a01b10ba01b75a

Fix: GWN Indexbuf creation was replacing the index buff bound to the last VAO

This led to problems such as the drawing of the navigate manipulator.
More details in the code comments.

===================================================================

M	intern/gawain/src/gwn_element.c

===================================================================

diff --git a/intern/gawain/src/gwn_element.c b/intern/gawain/src/gwn_element.c
index 0b7dc675f87..c56516817d6 100644
--- a/intern/gawain/src/gwn_element.c
+++ b/intern/gawain/src/gwn_element.c
@@ -262,8 +262,11 @@ void GWN_indexbuf_build_in_place(Gwn_IndexBufBuilder* builder, Gwn_IndexBuf* ele
 		elem->vbo_id = GWN_buf_id_alloc();
 
 	// send data to GPU
-	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, elem->vbo_id);
-	glBufferData(GL_ELEMENT_ARRAY_BUFFER, GWN_indexbuf_size_get(elem), builder->data, GL_STATIC_DRAW);
+	// GL_ELEMENT_ARRAY_BUFFER changes the state of the last VAO bound,
+	// so we use the GL_ARRAY_BUFFER here to create a buffer without
+	// interfering in the VAO state.
+	glBindBuffer(GL_ARRAY_BUFFER, elem->vbo_id);
+	glBufferData(GL_ARRAY_BUFFER, GWN_indexbuf_size_get(elem), builder->data, GL_STATIC_DRAW);
 
 	// discard builder (one-time use)
 	free(builder->data);