1 files changed, 268 insertions, 0 deletions
diff --git a/source/blender/gpu/intern/gpu_vertex_buffer.c b/source/blender/gpu/intern/gpu_vertex_buffer.c
new file mode 100644
index 00000000000..32f3d494015
--- /dev/null
+++ b/source/blender/gpu/intern/gpu_vertex_buffer.c
@@ -0,0 +1,268 @@
+/*
+ * ***** BEGIN GPL LICENSE BLOCK *****
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * The Original Code is Copyright (C) 2016 by Mike Erwin.
+ * All rights reserved.
+ *
+ * Contributor(s): Blender Foundation, Clément Foucault
+ *
+ * ***** END GPL LICENSE BLOCK *****
+ */
+
+/** \file blender/gpu/intern/gwn_vertex_buffer.c
+ *  \ingroup gpu
+ *
+ * Gawain vertex buffer
+ */
+
+#include "GPU_vertex_buffer.h"
+#include "GPU_buffer_id.h"
+#include "gpu_vertex_format_private.h"
+#include <stdlib.h>
+#include <string.h>
+
+#define KEEP_SINGLE_COPY 1
+
+static uint vbo_memory_usage;
+
+static GLenum convert_usage_type_to_gl(Gwn_UsageType type)
+{
+	static const GLenum table[] = {
+		[GWN_USAGE_STREAM] = GL_STREAM_DRAW,
+		[GWN_USAGE_STATIC] = GL_STATIC_DRAW,
+		[GWN_USAGE_DYNAMIC] = GL_DYNAMIC_DRAW
+	};
+	return table[type];
+}
+
+Gwn_VertBuf* GWN_vertbuf_create(Gwn_UsageType usage)
+{
+	Gwn_VertBuf* verts = malloc(sizeof(Gwn_VertBuf));
+	GWN_vertbuf_init(verts, usage);
+	return verts;
+}
+
+Gwn_VertBuf* GWN_vertbuf_create_with_format_ex(const Gwn_VertFormat* format, Gwn_UsageType usage)
+{
+	Gwn_VertBuf* verts = GWN_vertbuf_create(usage);
+	GWN_vertformat_copy(&verts->format, format);
+	if (!format->packed) {
+		VertexFormat_pack(&verts->format);
+	}
+	return verts;
+
+	/* this function might seem redundant, but there is potential for memory savings here... */
+	/* TODO: implement those memory savings */
+}
+
+void GWN_vertbuf_init(Gwn_VertBuf* verts, Gwn_UsageType usage)
+{
+	memset(verts, 0, sizeof(Gwn_VertBuf));
+	verts->usage = usage;
+	verts->dirty = true;
+}
+
+void GWN_vertbuf_init_with_format_ex(Gwn_VertBuf* verts, const Gwn_VertFormat* format, Gwn_UsageType usage)
+{
+	GWN_vertbuf_init(verts, usage);
+	GWN_vertformat_copy(&verts->format, format);
+	if (!format->packed) {
+		VertexFormat_pack(&verts->format);
+	}
+}
+
+void GWN_vertbuf_discard(Gwn_VertBuf* verts)
+{
+	if (verts->vbo_id) {
+		GWN_buf_id_free(verts->vbo_id);
+#if VRAM_USAGE
+		vbo_memory_usage -= GWN_vertbuf_size_get(verts);
+#endif
+	}
+	if (verts->data) {
+		free(verts->data);
+	}
+	free(verts);
+}
+
+uint GWN_vertbuf_size_get(const Gwn_VertBuf* verts)
+{
+	return vertex_buffer_size(&verts->format, verts->vertex_len);
+}
+
+/* create a new allocation, discarding any existing data */
+void GWN_vertbuf_data_alloc(Gwn_VertBuf* verts, uint v_len)
+{
+	Gwn_VertFormat* format = &verts->format;
+	if (!format->packed) {
+		VertexFormat_pack(format);
+	}
+#if TRUST_NO_ONE
+	/* catch any unnecessary use */
+	assert(verts->vertex_alloc != v_len || verts->data == NULL);
+#endif
+	/* only create the buffer the 1st time */
+	if (verts->vbo_id == 0) {
+		verts->vbo_id = GWN_buf_id_alloc();
+	}
+	/* discard previous data if any */
+	if (verts->data) {
+		free(verts->data);
+	}
+#if VRAM_USAGE
+	uint new_size = vertex_buffer_size(&verts->format, v_len);
+	vbo_memory_usage += new_size - GWN_vertbuf_size_get(verts);
+#endif
+	verts->dirty = true;
+	verts->vertex_len = verts->vertex_alloc = v_len;
+	verts->data = malloc(sizeof(GLubyte) * GWN_vertbuf_size_get(verts));
+}
+
+/* resize buffer keeping existing data */
+void GWN_vertbuf_data_resize(Gwn_VertBuf* verts, uint v_len)
+{
+#if TRUST_NO_ONE
+	assert(verts->data != NULL);
+	assert(verts->vertex_alloc != v_len);
+#endif
+
+#if VRAM_USAGE
+	uint new_size = vertex_buffer_size(&verts->format, v_len);
+	vbo_memory_usage += new_size - GWN_vertbuf_size_get(verts);
+#endif
+	verts->dirty = true;
+	verts->vertex_len = verts->vertex_alloc = v_len;
+	verts->data = realloc(verts->data, sizeof(GLubyte) * GWN_vertbuf_size_get(verts));
+}
+
+/* Set vertex count but does not change allocation.
+ * Only this many verts will be uploaded to the GPU and rendered.
+ * This is usefull for streaming data. */
+void GWN_vertbuf_vertex_count_set(Gwn_VertBuf* verts, uint v_len)
+{
+#if TRUST_NO_ONE
+	assert(verts->data != NULL); /* only for dynamic data */
+	assert(v_len <= verts->vertex_alloc);
+#endif
+
+#if VRAM_USAGE
+	uint new_size = vertex_buffer_size(&verts->format, v_len);
+	vbo_memory_usage += new_size - GWN_vertbuf_size_get(verts);
+#endif
+	verts->vertex_len = v_len;
+}
+
+void GWN_vertbuf_attr_set(Gwn_VertBuf* verts, uint a_idx, uint v_idx, const void* data)
+{
+	const Gwn_VertFormat* format = &verts->format;
+	const Gwn_VertAttr* a = format->attribs + a_idx;
+
+#if TRUST_NO_ONE
+	assert(a_idx < format->attr_len);
+	assert(v_idx < verts->vertex_alloc);
+	assert(verts->data != NULL);
+#endif
+	verts->dirty = true;
+	memcpy((GLubyte*)verts->data + a->offset + v_idx * format->stride, data, a->sz);
+}
+
+void GWN_vertbuf_attr_fill(Gwn_VertBuf* verts, uint a_idx, const void* data)
+{
+	const Gwn_VertFormat* format = &verts->format;
+	const Gwn_VertAttr* a = format->attribs + a_idx;
+
+#if TRUST_NO_ONE
+	assert(a_idx < format->attr_len);
+#endif
+	const uint stride = a->sz; /* tightly packed input data */
+
+	GWN_vertbuf_attr_fill_stride(verts, a_idx, stride, data);
+}
+
+void GWN_vertbuf_attr_fill_stride(Gwn_VertBuf* verts, uint a_idx, uint stride, const void* data)
+{
+	const Gwn_VertFormat* format = &verts->format;
+	const Gwn_VertAttr* a = format->attribs + a_idx;
+
+#if TRUST_NO_ONE
+	assert(a_idx < format->attr_len);
+	assert(verts->data != NULL);
+#endif
+	verts->dirty = true;
+	const uint vertex_len = verts->vertex_len;
+
+	if (format->attr_len == 1 && stride == format->stride) {
+		/* we can copy it all at once */
+		memcpy(verts->data, data, vertex_len * a->sz);
+	}
+	else {
+		/* we must copy it per vertex */
+		for (uint v = 0; v < vertex_len; ++v) {
+			memcpy((GLubyte*)verts->data + a->offset + v * format->stride, (const GLubyte*)data + v * stride, a->sz);
+		}
+	}
+}
+
+void GWN_vertbuf_attr_get_raw_data(Gwn_VertBuf* verts, uint a_idx, Gwn_VertBufRaw *access)
+{
+	const Gwn_VertFormat* format = &verts->format;
+	const Gwn_VertAttr* a = format->attribs + a_idx;
+
+#if TRUST_NO_ONE
+	assert(a_idx < format->attr_len);
+	assert(verts->data != NULL);
+#endif
+
+	verts->dirty = true;
+
+	access->size = a->sz;
+	access->stride = format->stride;
+	access->data = (GLubyte*)verts->data + a->offset;
+	access->data_init = access->data;
+#if TRUST_NO_ONE
+	access->_data_end = access->data_init + (size_t)(verts->vertex_alloc * format->stride);
+#endif
+}
+
+static void VertBuffer_upload_data(Gwn_VertBuf* verts)
+{
+	uint buffer_sz = GWN_vertbuf_size_get(verts);
+
+	/* orphan the vbo to avoid sync */
+	glBufferData(GL_ARRAY_BUFFER, buffer_sz, NULL, convert_usage_type_to_gl(verts->usage));
+	/* upload data */
+	glBufferSubData(GL_ARRAY_BUFFER, 0, buffer_sz, verts->data);
+
+	if (verts->usage == GWN_USAGE_STATIC) {
+		free(verts->data);
+		verts->data = NULL;
+	}
+	verts->dirty = false;
+}
+
+void GWN_vertbuf_use(Gwn_VertBuf* verts)
+{
+	glBindBuffer(GL_ARRAY_BUFFER, verts->vbo_id);
+	if (verts->dirty) {
+		VertBuffer_upload_data(verts);
+	}
+}
+
+uint GWN_vertbuf_get_memory_usage(void)
+{
+	return vbo_memory_usage;
+}