1 files changed, 75 insertions, 0 deletions
diff --git a/intern/gawain/gawain/gwn_element.h b/intern/gawain/gawain/gwn_element.h
new file mode 100644
index 00000000000..3081305769f
--- /dev/null
+++ b/intern/gawain/gawain/gwn_element.h
@@ -0,0 +1,75 @@
+
+// Gawain element list (AKA index buffer)
+//
+// This code is part of the Gawain library, with modifications
+// specific to integration with Blender.
+//
+// Copyright 2016 Mike Erwin
+//
+// This Source Code Form is subject to the terms of the Mozilla Public License, v. 2.0. If a copy of
+// the MPL was not distributed with this file, You can obtain one at https://mozilla.org/MPL/2.0/.
+
+#pragma once
+
+#include "gwn_primitive.h"
+
+#define GWN_TRACK_INDEX_RANGE 1
+
+typedef enum {
+	GWN_INDEX_U8, // GL has this, Vulkan does not
+	GWN_INDEX_U16,
+	GWN_INDEX_U32
+} Gwn_IndexBufType;
+
+typedef struct Gwn_IndexBuf {
+	unsigned index_ct;
+#if GWN_TRACK_INDEX_RANGE
+	Gwn_IndexBufType index_type;
+	GLenum gl_index_type;
+	unsigned min_index;
+	unsigned max_index;
+	unsigned base_index;
+#endif
+	void* data; // NULL indicates data in VRAM (unmapped) or not yet allocated
+	GLuint vbo_id; // 0 indicates not yet sent to VRAM
+} Gwn_IndexBuf;
+
+void GWN_indexbuf_use(Gwn_IndexBuf*);
+unsigned GWN_indexbuf_size_get(const Gwn_IndexBuf*);
+
+typedef struct Gwn_IndexBufBuilder {
+	unsigned max_allowed_index;
+	unsigned max_index_ct;
+	unsigned index_ct;
+	Gwn_PrimType prim_type;
+	unsigned* data;
+} Gwn_IndexBufBuilder;
+
+// supported primitives:
+//  GWN_PRIM_POINTS
+//  GWN_PRIM_LINES
+//  GWN_PRIM_TRIS
+
+void GWN_indexbuf_init(Gwn_IndexBufBuilder*, Gwn_PrimType, unsigned prim_ct, unsigned vertex_ct);
+//void GWN_indexbuf_init_custom(Gwn_IndexBufBuilder*, Gwn_PrimType, unsigned index_ct, unsigned vertex_ct);
+
+void GWN_indexbuf_add_generic_vert(Gwn_IndexBufBuilder*, unsigned v);
+
+void GWN_indexbuf_add_point_vert(Gwn_IndexBufBuilder*, unsigned v);
+void GWN_indexbuf_add_line_verts(Gwn_IndexBufBuilder*, unsigned v1, unsigned v2);
+void GWN_indexbuf_add_tri_verts(Gwn_IndexBufBuilder*, unsigned v1, unsigned v2, unsigned v3);
+
+Gwn_IndexBuf* GWN_indexbuf_build(Gwn_IndexBufBuilder*);
+void GWN_indexbuf_build_in_place(Gwn_IndexBufBuilder*, Gwn_IndexBuf*);
+
+void GWN_indexbuf_discard(Gwn_IndexBuf*);
+
+
+/* Macros */
+
+#define GWN_INDEXBUF_DISCARD_SAFE(elem) do { \
+	if (elem != NULL) { \
+		GWN_indexbuf_discard(elem); \
+		elem = NULL; \
+	} \
+} while (0)