mutter/cogl/cogl-indices.c

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/*
* Cogl
*
* An object oriented GL/GLES Abstraction/Utility Layer
*
* Copyright (C) 2010 Intel Corporation.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library. If not, see
* <http://www.gnu.org/licenses/>.
*
*
*
* Authors:
* Robert Bragg <robert@linux.intel.com>
* Neil Roberts <neil@linux.intel.com>
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "cogl-util.h"
#include "cogl-object-private.h"
#include "cogl-context-private.h"
#include "cogl-indices.h"
#include "cogl-indices-private.h"
#include "cogl-index-buffer.h"
#include <stdarg.h>
static void _cogl_indices_free (CoglIndices *indices);
COGL_OBJECT_DEFINE (Indices, indices);
static size_t
sizeof_indices_type (CoglIndicesType type)
{
switch (type)
{
case COGL_INDICES_TYPE_UNSIGNED_BYTE:
return 1;
case COGL_INDICES_TYPE_UNSIGNED_SHORT:
return 2;
case COGL_INDICES_TYPE_UNSIGNED_INT:
return 4;
}
g_return_val_if_reached (0);
}
CoglIndices *
cogl_indices_new_for_buffer (CoglIndicesType type,
CoglIndexBuffer *buffer,
size_t offset)
{
CoglIndices *indices = g_slice_new (CoglIndices);
indices->buffer = cogl_object_ref (buffer);
indices->offset = offset;
indices->type = type;
indices->immutable_ref = 0;
return _cogl_indices_object_new (indices);
}
CoglIndices *
cogl_indices_new (CoglContext *context,
CoglIndicesType type,
const void *indices_data,
int n_indices)
{
size_t buffer_bytes = sizeof_indices_type (type) * n_indices;
CoglIndexBuffer *index_buffer = cogl_index_buffer_new (context, buffer_bytes);
CoglBuffer *buffer = COGL_BUFFER (index_buffer);
CoglIndices *indices;
cogl_buffer_set_data (buffer,
0,
indices_data,
buffer_bytes);
indices = cogl_indices_new_for_buffer (type, index_buffer, 0);
cogl_object_unref (index_buffer);
return indices;
}
CoglIndexBuffer *
cogl_indices_get_buffer (CoglIndices *indices)
{
return indices->buffer;
}
CoglIndicesType
cogl_indices_get_type (CoglIndices *indices)
{
_COGL_RETURN_VAL_IF_FAIL (cogl_is_indices (indices),
COGL_INDICES_TYPE_UNSIGNED_BYTE);
return indices->type;
}
size_t
cogl_indices_get_offset (CoglIndices *indices)
{
_COGL_RETURN_VAL_IF_FAIL (cogl_is_indices (indices), 0);
return indices->offset;
}
static void
warn_about_midscene_changes (void)
{
static CoglBool seen = FALSE;
if (!seen)
{
g_warning ("Mid-scene modification of indices has "
"undefined results\n");
seen = TRUE;
}
}
void
cogl_indices_set_offset (CoglIndices *indices,
size_t offset)
{
_COGL_RETURN_IF_FAIL (cogl_is_indices (indices));
if (G_UNLIKELY (indices->immutable_ref))
warn_about_midscene_changes ();
indices->offset = offset;
}
static void
_cogl_indices_free (CoglIndices *indices)
{
cogl_object_unref (indices->buffer);
g_slice_free (CoglIndices, indices);
}
CoglIndices *
_cogl_indices_immutable_ref (CoglIndices *indices)
{
_COGL_RETURN_VAL_IF_FAIL (cogl_is_indices (indices), NULL);
indices->immutable_ref++;
_cogl_buffer_immutable_ref (COGL_BUFFER (indices->buffer));
return indices;
}
void
_cogl_indices_immutable_unref (CoglIndices *indices)
{
_COGL_RETURN_IF_FAIL (cogl_is_indices (indices));
_COGL_RETURN_IF_FAIL (indices->immutable_ref > 0);
indices->immutable_ref--;
_cogl_buffer_immutable_unref (COGL_BUFFER (indices->buffer));
}
CoglIndices *
cogl_get_rectangle_indices (CoglContext *ctx, int n_rectangles)
{
int n_indices = n_rectangles * 6;
/* Check if the largest index required will fit in a byte array... */
if (n_indices <= 256 / 4 * 6)
{
/* Generate the byte array if we haven't already */
if (ctx->rectangle_byte_indices == NULL)
{
uint8_t *byte_array = g_malloc (256 / 4 * 6 * sizeof (uint8_t));
uint8_t *p = byte_array;
int i, vert_num = 0;
for (i = 0; i < 256 / 4; i++)
{
*(p++) = vert_num + 0;
*(p++) = vert_num + 1;
*(p++) = vert_num + 2;
*(p++) = vert_num + 0;
*(p++) = vert_num + 2;
*(p++) = vert_num + 3;
vert_num += 4;
}
ctx->rectangle_byte_indices
= cogl_indices_new (ctx,
COGL_INDICES_TYPE_UNSIGNED_BYTE,
byte_array,
256 / 4 * 6);
g_free (byte_array);
}
return ctx->rectangle_byte_indices;
}
else
{
if (ctx->rectangle_short_indices_len < n_indices)
{
uint16_t *short_array;
uint16_t *p;
int i, vert_num = 0;
if (ctx->rectangle_short_indices != NULL)
cogl_object_unref (ctx->rectangle_short_indices);
/* Pick a power of two >= MAX (512, n_indices) */
if (ctx->rectangle_short_indices_len == 0)
ctx->rectangle_short_indices_len = 512;
while (ctx->rectangle_short_indices_len < n_indices)
ctx->rectangle_short_indices_len *= 2;
/* Over-allocate to generate a whole number of quads */
p = short_array = g_malloc ((ctx->rectangle_short_indices_len
+ 5) / 6 * 6
* sizeof (uint16_t));
/* Fill in the complete quads */
for (i = 0; i < ctx->rectangle_short_indices_len; i += 6)
{
*(p++) = vert_num + 0;
*(p++) = vert_num + 1;
*(p++) = vert_num + 2;
*(p++) = vert_num + 0;
*(p++) = vert_num + 2;
*(p++) = vert_num + 3;
vert_num += 4;
}
ctx->rectangle_short_indices
= cogl_indices_new (ctx,
COGL_INDICES_TYPE_UNSIGNED_SHORT,
short_array,
ctx->rectangle_short_indices_len);
g_free (short_array);
}
return ctx->rectangle_short_indices;
}
}