1 files changed, 125 insertions, 0 deletions
diff --git a/intern/gawain/gawain/gwn_vertex_buffer.h b/intern/gawain/gawain/gwn_vertex_buffer.h
new file mode 100644
index 00000000000..e9a37519b36
--- /dev/null
+++ b/intern/gawain/gawain/gwn_vertex_buffer.h
@@ -0,0 +1,125 @@
+
+// Gawain vertex 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_vertex_format.h"
+
+#define VRAM_USAGE 1
+// How to create a Gwn_VertBuf:
+// 1) verts = GWN_vertbuf_create() or GWN_vertbuf_init(verts)
+// 2) GWN_vertformat_attr_add(verts->format, ...)
+// 3) GWN_vertbuf_data_alloc(verts, vertex_ct) <-- finalizes/packs vertex format
+// 4) GWN_vertbuf_attr_fill(verts, pos, application_pos_buffer)
+
+// Is Gwn_VertBuf always used as part of a Gwn_Batch?
+
+typedef enum {
+	// can be extended to support more types
+	GWN_USAGE_STREAM,
+	GWN_USAGE_STATIC, // do not keep data in memory
+	GWN_USAGE_DYNAMIC
+} Gwn_UsageType;
+
+typedef struct Gwn_VertBuf {
+	Gwn_VertFormat format;
+	unsigned vertex_ct;    // number of verts we want to draw
+	unsigned vertex_alloc; // number of verts data
+	bool dirty;
+	GLubyte* data; // NULL indicates data in VRAM (unmapped)
+	GLuint vbo_id; // 0 indicates not yet allocated
+	Gwn_UsageType usage; // usage hint for GL optimisation
+} Gwn_VertBuf;
+
+Gwn_VertBuf* GWN_vertbuf_create(Gwn_UsageType);
+Gwn_VertBuf* GWN_vertbuf_create_with_format_ex(const Gwn_VertFormat*, Gwn_UsageType);
+
+#define GWN_vertbuf_create_with_format(format) \
+	GWN_vertbuf_create_with_format_ex(format, GWN_USAGE_STATIC)
+
+void GWN_vertbuf_discard(Gwn_VertBuf*);
+
+void GWN_vertbuf_init(Gwn_VertBuf*, Gwn_UsageType);
+void GWN_vertbuf_init_with_format_ex(Gwn_VertBuf*, const Gwn_VertFormat*, Gwn_UsageType);
+
+#define GWN_vertbuf_init_with_format(verts, format) \
+	GWN_vertbuf_init_with_format_ex(verts, format, GWN_USAGE_STATIC)
+
+unsigned GWN_vertbuf_size_get(const Gwn_VertBuf*);
+void GWN_vertbuf_data_alloc(Gwn_VertBuf*, unsigned v_ct);
+void GWN_vertbuf_data_resize(Gwn_VertBuf*, unsigned v_ct);
+void GWN_vertbuf_vertex_count_set(Gwn_VertBuf*, unsigned v_ct);
+
+// The most important set_attrib variant is the untyped one. Get it right first.
+// It takes a void* so the app developer is responsible for matching their app data types
+// to the vertex attribute's type and component count. They're in control of both, so this
+// should not be a problem.
+
+void GWN_vertbuf_attr_set(Gwn_VertBuf*, unsigned a_idx, unsigned v_idx, const void* data);
+void GWN_vertbuf_attr_fill(Gwn_VertBuf*, unsigned a_idx, const void* data); // tightly packed, non interleaved input data
+void GWN_vertbuf_attr_fill_stride(Gwn_VertBuf*, unsigned a_idx, unsigned stride, const void* data);
+
+// For low level access only
+typedef struct Gwn_VertBufRaw {
+	unsigned size;
+	unsigned stride;
+	GLubyte* data;
+	GLubyte* data_init;
+#if TRUST_NO_ONE
+	// Only for overflow check
+	GLubyte* _data_end;
+#endif
+} Gwn_VertBufRaw;
+
+GWN_INLINE void *GWN_vertbuf_raw_step(Gwn_VertBufRaw *a)
+	{
+	GLubyte* data = a->data;
+	a->data += a->stride;
+#if TRUST_NO_ONE
+	assert(data < a->_data_end);
+#endif
+	return (void *)data;
+	}
+
+GWN_INLINE unsigned GWN_vertbuf_raw_used(Gwn_VertBufRaw *a)
+	{
+	return ((a->data - a->data_init) / a->stride);
+	}
+
+void GWN_vertbuf_attr_get_raw_data(Gwn_VertBuf*, unsigned a_idx, Gwn_VertBufRaw *access);
+
+// TODO: decide whether to keep the functions below
+// doesn't immediate mode satisfy these needs?
+
+//	void setAttrib1f(unsigned a_idx, unsigned v_idx, float x);
+//	void setAttrib2f(unsigned a_idx, unsigned v_idx, float x, float y);
+//	void setAttrib3f(unsigned a_idx, unsigned v_idx, float x, float y, float z);
+//	void setAttrib4f(unsigned a_idx, unsigned v_idx, float x, float y, float z, float w);
+//
+//	void setAttrib3ub(unsigned a_idx, unsigned v_idx, unsigned char r, unsigned char g, unsigned char b);
+//	void setAttrib4ub(unsigned a_idx, unsigned v_idx, unsigned char r, unsigned char g, unsigned char b, unsigned char a);
+
+void GWN_vertbuf_use(Gwn_VertBuf*);
+
+
+// Metrics
+
+unsigned GWN_vertbuf_get_memory_usage(void);
+
+
+// Macros
+
+#define GWN_VERTBUF_DISCARD_SAFE(verts) do { \
+	if (verts != NULL) { \
+		GWN_vertbuf_discard(verts); \
+		verts = NULL; \
+	} \
+} while (0)