static void *
lp_setup_map_vertices(struct vbuf_render *vbr)
{
struct lp_setup_context *setup = lp_setup_context(vbr);
return setup->vertex_buffer;
}
static void
lp_setup_set_primitive(struct vbuf_render *vbr, unsigned prim)
{
lp_setup_context(vbr)->prim = prim;
}
/**
* This function is hit when the draw module is working in pass-through mode.
* It's up to us to convert the vertex array into point/line/tri prims.
*/
static void
lp_setup_draw_arrays(struct vbuf_render *vbr, uint start, uint nr)
{
struct lp_setup_context *setup = lp_setup_context(vbr);
const unsigned stride = setup->vertex_info->size * sizeof(float);
const void *vertex_buffer =
(void *) get_vert(setup->vertex_buffer, start, stride);
const boolean flatshade_first = setup->flatshade_first;
unsigned i;
if (!lp_setup_update_state(setup, TRUE))
return;
switch (setup->prim) {
case PIPE_PRIM_POINTS:
for (i = 0; i < nr; i++) {
setup->point( setup,
get_vert(vertex_buffer, i-0, stride) );
}
break;
case PIPE_PRIM_LINES:
for (i = 1; i < nr; i += 2) {
setup->line( setup,
get_vert(vertex_buffer, i-1, stride),
get_vert(vertex_buffer, i-0, stride) );
}
break;
case PIPE_PRIM_LINE_STRIP:
for (i = 1; i < nr; i ++) {
setup->line( setup,
get_vert(vertex_buffer, i-1, stride),
get_vert(vertex_buffer, i-0, stride) );
}
break;
case PIPE_PRIM_LINE_LOOP:
for (i = 1; i < nr; i ++) {
setup->line( setup,
get_vert(vertex_buffer, i-1, stride),
get_vert(vertex_buffer, i-0, stride) );
}
if (nr) {
setup->line( setup,
get_vert(vertex_buffer, nr-1, stride),
get_vert(vertex_buffer, 0, stride) );
}
break;
case PIPE_PRIM_TRIANGLES:
for (i = 2; i < nr; i += 3) {
setup->triangle( setup,
get_vert(vertex_buffer, i-2, stride),
get_vert(vertex_buffer, i-1, stride),
get_vert(vertex_buffer, i-0, stride) );
}
break;
case PIPE_PRIM_TRIANGLE_STRIP:
if (flatshade_first) {
for (i = 2; i < nr; i++) {
/* emit first triangle vertex as first triangle vertex */
setup->triangle( setup,
get_vert(vertex_buffer, i-2, stride),
get_vert(vertex_buffer, i+(i&1)-1, stride),
get_vert(vertex_buffer, i-(i&1), stride) );
}
}
else {
for (i = 2; i < nr; i++) {
/* emit last triangle vertex as last triangle vertex */
setup->triangle( setup,
get_vert(vertex_buffer, i+(i&1)-2, stride),
get_vert(vertex_buffer, i-(i&1)-1, stride),
get_vert(vertex_buffer, i-0, stride) );
}
}
break;
case PIPE_PRIM_TRIANGLE_FAN:
if (flatshade_first) {
for (i = 2; i < nr; i += 1) {
/* emit first non-spoke vertex as first vertex */
setup->triangle( setup,
get_vert(vertex_buffer, i-1, stride),
get_vert(vertex_buffer, i-0, stride),
get_vert(vertex_buffer, 0, stride) );
}
}
else {
for (i = 2; i < nr; i += 1) {
/* emit last non-spoke vertex as last vertex */
setup->triangle( setup,
get_vert(vertex_buffer, 0, stride),
get_vert(vertex_buffer, i-1, stride),
get_vert(vertex_buffer, i-0, stride) );
}
}
break;
case PIPE_PRIM_QUADS:
/* GL quads don't follow provoking vertex convention */
if (flatshade_first) {
/* emit last quad vertex as first triangle vertex */
for (i = 3; i < nr; i += 4) {
setup->triangle( setup,
get_vert(vertex_buffer, i-0, stride),
get_vert(vertex_buffer, i-3, stride),
get_vert(vertex_buffer, i-2, stride) );
setup->triangle( setup,
get_vert(vertex_buffer, i-0, stride),
get_vert(vertex_buffer, i-2, stride),
get_vert(vertex_buffer, i-1, stride) );
}
}
else {
/* emit last quad vertex as last triangle vertex */
for (i = 3; i < nr; i += 4) {
setup->triangle( setup,
get_vert(vertex_buffer, i-3, stride),
get_vert(vertex_buffer, i-2, stride),
get_vert(vertex_buffer, i-0, stride) );
setup->triangle( setup,
get_vert(vertex_buffer, i-2, stride),
get_vert(vertex_buffer, i-1, stride),
get_vert(vertex_buffer, i-0, stride) );
}
}
break;
case PIPE_PRIM_QUAD_STRIP:
/* GL quad strips don't follow provoking vertex convention */
if (flatshade_first) {
/* emit last quad vertex as first triangle vertex */
for (i = 3; i < nr; i += 2) {
setup->triangle( setup,
get_vert(vertex_buffer, i-0, stride),
get_vert(vertex_buffer, i-3, stride),
get_vert(vertex_buffer, i-2, stride) );
setup->triangle( setup,
get_vert(vertex_buffer, i-0, stride),
get_vert(vertex_buffer, i-1, stride),
get_vert(vertex_buffer, i-3, stride) );
}
}
else {
/* emit last quad vertex as last triangle vertex */
for (i = 3; i < nr; i += 2) {
setup->triangle( setup,
get_vert(vertex_buffer, i-3, stride),
get_vert(vertex_buffer, i-2, stride),
get_vert(vertex_buffer, i-0, stride) );
setup->triangle( setup,
get_vert(vertex_buffer, i-1, stride),
get_vert(vertex_buffer, i-3, stride),
get_vert(vertex_buffer, i-0, stride) );
}
}
break;
case PIPE_PRIM_POLYGON:
/* Almost same as tri fan but the _first_ vertex specifies the flat
* shading color.
*/
if (flatshade_first) {
/* emit first polygon vertex as first triangle vertex */
for (i = 2; i < nr; i += 1) {
setup->triangle( setup,
get_vert(vertex_buffer, 0, stride),
get_vert(vertex_buffer, i-1, stride),
get_vert(vertex_buffer, i-0, stride) );
}
}
else {
/* emit first polygon vertex as last triangle vertex */
for (i = 2; i < nr; i += 1) {
setup->triangle( setup,
get_vert(vertex_buffer, i-1, stride),
get_vert(vertex_buffer, i-0, stride),
get_vert(vertex_buffer, 0, stride) );
}
}
break;
default:
assert(0);
}
}
static boolean
lp_setup_set_primitive(struct vbuf_render *vbr, unsigned prim)
{
lp_setup_context(vbr)->prim = prim;
return TRUE;
}