void
vbo_split_prims(struct gl_context *ctx,
const struct gl_vertex_array *arrays[],
const struct _mesa_prim *prim,
GLuint nr_prims,
const struct _mesa_index_buffer *ib,
GLuint min_index,
GLuint max_index,
vbo_draw_func draw,
const struct split_limits *limits)
{
if (ib) {
if (limits->max_indices == 0) {
/* Could traverse the indices, re-emitting vertices in turn.
* But it's hard to see why this case would be needed - for
* software tnl, it is better to convert to non-indexed
* rendering after transformation is complete. Are there any devices
* with hardware tnl that cannot do indexed rendering?
*
* For now, this path is disabled.
*/
assert(0);
}
else if (max_index - min_index >= limits->max_verts) {
/* The vertex buffers are too large for hardware (or the
* swtnl module). Traverse the indices, re-emitting vertices
* in turn. Use a vertex cache to preserve some of the
* sharing from the original index list.
*/
vbo_split_copy(ctx, arrays, prim, nr_prims, ib, draw, limits);
}
else if (ib->count > limits->max_indices) {
/* The index buffer is too large for hardware. Try to split
* on whole-primitive boundaries, otherwise try to split the
* individual primitives.
*/
vbo_split_inplace(ctx, arrays, prim, nr_prims, ib,
min_index, max_index, draw, limits);
}
else {
/* Why were we called? */
assert(0);
}
}
else {
if (max_index - min_index >= limits->max_verts) {
/* The vertex buffer is too large for hardware (or the swtnl
* module). Try to split on whole-primitive boundaries,
* otherwise try to split the individual primitives.
*/
vbo_split_inplace(ctx, arrays, prim, nr_prims, ib,
min_index, max_index, draw, limits);
}
else {
/* Why were we called? */
assert(0);
}
}
}
/* Break large primitives into smaller ones. If not possible, convert
* the primitive to indexed and pass to split_elts().
*/
static void split_prims( struct split_context *split)
{
GLuint csr = 0;
GLuint i;
for (i = 0; i < split->nr_prims; i++) {
const struct _mesa_prim *prim = &split->prim[i];
GLuint first, incr;
GLboolean split_inplace = split_prim_inplace(prim->mode, &first, &incr);
GLuint count;
/* Always wrap on an even numbered vertex to avoid problems with
* triangle strips.
*/
GLuint available = align(split->limits->max_verts - csr - 1, 2);
assert(split->limits->max_verts >= csr);
if (prim->count < first)
continue;
count = prim->count - (prim->count - first) % incr;
if ((available < count && !split_inplace) ||
(available < first && split_inplace)) {
flush_vertex(split);
csr = 0;
available = align(split->limits->max_verts - csr - 1, 2);
}
if (available >= count) {
struct _mesa_prim *outprim = next_outprim(split);
*outprim = *prim;
csr += prim->count;
available = align(split->limits->max_verts - csr - 1, 2);
}
else if (split_inplace) {
GLuint j, nr;
for (j = 0 ; j < count ; ) {
GLuint remaining = count - j;
struct _mesa_prim *outprim = next_outprim(split);
nr = MIN2( available, remaining );
nr -= (nr - first) % incr;
outprim->mode = prim->mode;
outprim->begin = (j == 0 && prim->begin);
outprim->end = (nr == remaining && prim->end);
outprim->start = prim->start + j;
outprim->count = nr;
if (nr == remaining) {
/* Finished.
*/
j += nr;
csr += nr;
available = align(split->limits->max_verts - csr - 1, 2);
}
else {
/* Wrapped the primitive:
*/
j += nr - (first - incr);
flush_vertex(split);
csr = 0;
available = align(split->limits->max_verts - csr - 1, 2);
}
}
}
else if (split->ib == NULL) {
/* XXX: could at least send the first max_verts off from the
* inplace buffers.
*/
/* else convert to indexed primitive and pass to split_elts,
* which will do the necessary copying and turn it back into a
* vertex primitive for rendering...
*/
struct _mesa_index_buffer ib;
struct _mesa_prim tmpprim;
GLuint *elts = malloc(count * sizeof(GLuint));
GLuint j;
for (j = 0; j < count; j++)
elts[j] = prim->start + j;
ib.count = count;
ib.type = GL_UNSIGNED_INT;
ib.obj = split->ctx->Shared->NullBufferObj;
ib.ptr = elts;
tmpprim = *prim;
tmpprim.indexed = 1;
tmpprim.start = 0;
tmpprim.count = count;
flush_vertex(split);
vbo_split_copy(split->ctx,
split->array,
&tmpprim, 1,
&ib,
split->draw,
split->limits);
free(elts);
}
else {
flush_vertex(split);
vbo_split_copy(split->ctx,
split->array,
prim, 1,
split->ib,
split->draw,
split->limits);
}
}
flush_vertex(split);
}