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/*
* ***** 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
*
* ***** END GPL LICENSE BLOCK *****
*/
/** \file blender/gpu/intern/gpu_element.c
* \ingroup gpu
*
* GPU element list (AKA index buffer)
*/
#include "MEM_guardedalloc.h"
#include "GPU_element.h"
#include "gpu_context_private.h"
#include <stdlib.h>
#define KEEP_SINGLE_COPY 1
static GLenum convert_index_type_to_gl(GPUIndexBufType type)
{
static const GLenum table[] = {
[GPU_INDEX_U8] = GL_UNSIGNED_BYTE, /* GL has this, Vulkan does not */
[GPU_INDEX_U16] = GL_UNSIGNED_SHORT,
[GPU_INDEX_U32] = GL_UNSIGNED_INT
};
return table[type];
}
uint GPU_indexbuf_size_get(const GPUIndexBuf *elem)
{
#if GPU_TRACK_INDEX_RANGE
static const uint table[] = {
[GPU_INDEX_U8] = sizeof(GLubyte), /* GL has this, Vulkan does not */
[GPU_INDEX_U16] = sizeof(GLushort),
[GPU_INDEX_U32] = sizeof(GLuint)
};
return elem->index_len * table[elem->index_type];
#else
return elem->index_len * sizeof(GLuint);
#endif
}
void GPU_indexbuf_init_ex(
GPUIndexBufBuilder *builder, GPUPrimType prim_type,
uint index_len, uint vertex_len, bool use_prim_restart)
{
builder->use_prim_restart = use_prim_restart;
builder->max_allowed_index = vertex_len - 1;
builder->max_index_len = index_len;
builder->index_len = 0; // start empty
builder->prim_type = prim_type;
builder->data = MEM_callocN(builder->max_index_len * sizeof(uint), "GPUIndexBuf data");
}
void GPU_indexbuf_init(GPUIndexBufBuilder *builder, GPUPrimType prim_type, uint prim_len, uint vertex_len)
{
uint verts_per_prim = 0;
switch (prim_type) {
case GPU_PRIM_POINTS:
verts_per_prim = 1;
break;
case GPU_PRIM_LINES:
verts_per_prim = 2;
break;
case GPU_PRIM_TRIS:
verts_per_prim = 3;
break;
case GPU_PRIM_LINES_ADJ:
verts_per_prim = 4;
break;
default:
#if TRUST_NO_ONE
assert(false);
#endif
return;
}
GPU_indexbuf_init_ex(builder, prim_type, prim_len * verts_per_prim, vertex_len, false);
}
void GPU_indexbuf_add_generic_vert(GPUIndexBufBuilder *builder, uint v)
{
#if TRUST_NO_ONE
assert(builder->data != NULL);
assert(builder->index_len < builder->max_index_len);
assert(v <= builder->max_allowed_index);
#endif
builder->data[builder->index_len++] = v;
}
void GPU_indexbuf_add_primitive_restart(GPUIndexBufBuilder *builder)
{
#if TRUST_NO_ONE
assert(builder->data != NULL);
assert(builder->index_len < builder->max_index_len);
assert(builder->use_prim_restart);
#endif
builder->data[builder->index_len++] = GPU_PRIM_RESTART;
}
void GPU_indexbuf_add_point_vert(GPUIndexBufBuilder *builder, uint v)
{
#if TRUST_NO_ONE
assert(builder->prim_type == GPU_PRIM_POINTS);
#endif
GPU_indexbuf_add_generic_vert(builder, v);
}
void GPU_indexbuf_add_line_verts(GPUIndexBufBuilder *builder, uint v1, uint v2)
{
#if TRUST_NO_ONE
assert(builder->prim_type == GPU_PRIM_LINES);
assert(v1 != v2);
#endif
GPU_indexbuf_add_generic_vert(builder, v1);
GPU_indexbuf_add_generic_vert(builder, v2);
}
void GPU_indexbuf_add_tri_verts(GPUIndexBufBuilder *builder, uint v1, uint v2, uint v3)
{
#if TRUST_NO_ONE
assert(builder->prim_type == GPU_PRIM_TRIS);
assert(v1 != v2 && v2 != v3 && v3 != v1);
#endif
GPU_indexbuf_add_generic_vert(builder, v1);
GPU_indexbuf_add_generic_vert(builder, v2);
GPU_indexbuf_add_generic_vert(builder, v3);
}
void GPU_indexbuf_add_line_adj_verts(GPUIndexBufBuilder *builder, uint v1, uint v2, uint v3, uint v4)
{
#if TRUST_NO_ONE
assert(builder->prim_type == GPU_PRIM_LINES_ADJ);
assert(v2 != v3); /* only the line need diff indices */
#endif
GPU_indexbuf_add_generic_vert(builder, v1);
GPU_indexbuf_add_generic_vert(builder, v2);
GPU_indexbuf_add_generic_vert(builder, v3);
GPU_indexbuf_add_generic_vert(builder, v4);
}
#if GPU_TRACK_INDEX_RANGE
/* Everything remains 32 bit while building to keep things simple.
* Find min/max after, then convert to smallest index type possible. */
static uint index_range(const uint values[], uint value_len, uint *min_out, uint *max_out)
{
if (value_len == 0) {
*min_out = 0;
*max_out = 0;
return 0;
}
uint min_value = values[0];
uint max_value = values[0];
for (uint i = 1; i < value_len; ++i) {
const uint value = values[i];
if (value == GPU_PRIM_RESTART)
continue;
else if (value < min_value)
min_value = value;
else if (value > max_value)
max_value = value;
}
*min_out = min_value;
*max_out = max_value;
return max_value - min_value;
}
static void squeeze_indices_byte(GPUIndexBufBuilder *builder, GPUIndexBuf *elem)
{
const uint *values = builder->data;
const uint index_len = elem->index_len;
/* data will never be *larger* than builder->data...
* converting in place to avoid extra allocation */
GLubyte *data = (GLubyte *)builder->data;
if (elem->max_index > 0xFF) {
const uint base = elem->min_index;
elem->base_index = base;
elem->min_index = 0;
elem->max_index -= base;
for (uint i = 0; i < index_len; ++i) {
data[i] = (values[i] == GPU_PRIM_RESTART) ? 0xFF : (GLubyte)(values[i] - base);
}
}
else {
elem->base_index = 0;
for (uint i = 0; i < index_len; ++i) {
data[i] = (GLubyte)(values[i]);
}
}
}
static void squeeze_indices_short(GPUIndexBufBuilder *builder, GPUIndexBuf *elem)
{
const uint *values = builder->data;
const uint index_len = elem->index_len;
/* data will never be *larger* than builder->data...
* converting in place to avoid extra allocation */
GLushort *data = (GLushort *)builder->data;
if (elem->max_index > 0xFFFF) {
const uint base = elem->min_index;
elem->base_index = base;
elem->min_index = 0;
elem->max_index -= base;
for (uint i = 0; i < index_len; ++i) {
data[i] = (values[i] == GPU_PRIM_RESTART) ? 0xFFFF : (GLushort)(values[i] - base);
}
}
else {
elem->base_index = 0;
for (uint i = 0; i < index_len; ++i) {
data[i] = (GLushort)(values[i]);
}
}
}
#endif /* GPU_TRACK_INDEX_RANGE */
GPUIndexBuf *GPU_indexbuf_build(GPUIndexBufBuilder *builder)
{
GPUIndexBuf *elem = MEM_callocN(sizeof(GPUIndexBuf), "GPUIndexBuf");
GPU_indexbuf_build_in_place(builder, elem);
return elem;
}
void GPU_indexbuf_build_in_place(GPUIndexBufBuilder *builder, GPUIndexBuf *elem)
{
#if TRUST_NO_ONE
assert(builder->data != NULL);
#endif
elem->index_len = builder->index_len;
elem->use_prim_restart = builder->use_prim_restart;
#if GPU_TRACK_INDEX_RANGE
uint range = index_range(builder->data, builder->index_len, &elem->min_index, &elem->max_index);
/* count the primitive restart index. */
if (elem->use_prim_restart) {
range += 1;
}
if (range <= 0xFF) {
elem->index_type = GPU_INDEX_U8;
squeeze_indices_byte(builder, elem);
}
else if (range <= 0xFFFF) {
elem->index_type = GPU_INDEX_U16;
squeeze_indices_short(builder, elem);
}
else {
elem->index_type = GPU_INDEX_U32;
elem->base_index = 0;
}
elem->gl_index_type = convert_index_type_to_gl(elem->index_type);
#endif
if (elem->vbo_id == 0) {
elem->vbo_id = GPU_buf_alloc();
}
/* send data to GPU */
/* 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, GPU_indexbuf_size_get(elem), builder->data, GL_STATIC_DRAW);
/* discard builder (one-time use) */
MEM_freeN(builder->data);
builder->data = NULL;
/* other fields are safe to leave */
}
void GPU_indexbuf_use(GPUIndexBuf *elem)
{
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, elem->vbo_id);
}
void GPU_indexbuf_discard(GPUIndexBuf *elem)
{
if (elem->vbo_id) {
GPU_buf_free(elem->vbo_id);
}
MEM_freeN(elem);
}
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