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/*
* Mesa 3-D graphics library
*
* Copyright 2008 VMware, Inc.
* Copyright (C) 2010 LunarG Inc.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included
* in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*
* Authors:
* Keith Whitwell <keithw@vmware.com>
* Chia-I Wu <olv@lunarg.com>
*/
/* these macros are optional */
#ifndef LOCAL_VARS
#define LOCAL_VARS
#endif
#ifndef FUNC_ENTER
#define FUNC_ENTER do {} while (0)
#endif
#ifndef FUNC_EXIT
#define FUNC_EXIT do {} while (0)
#endif
#ifndef LINE_ADJ
#define LINE_ADJ(flags, a0, i0, i1, a1) LINE(flags, i0, i1)
#endif
#ifndef TRIANGLE_ADJ
#define TRIANGLE_ADJ(flags, i0, a0, i1, a1, i2, a2) TRIANGLE(flags, i0, i1, i2)
#endif
static void
FUNC(FUNC_VARS)
{
unsigned idx[6], i;
ushort flags;
LOCAL_VARS
FUNC_ENTER;
/* prim, prim_flags, count, and last_vertex_last should have been defined */
if (0) {
debug_printf("%s: prim 0x%x, prim_flags 0x%x, count %d, last_vertex_last %d\n",
__FUNCTION__, prim, prim_flags, count, last_vertex_last);
}
switch (prim) {
case PIPE_PRIM_POINTS:
for (i = 0; i < count; i++) {
idx[0] = GET_ELT(i);
POINT(idx[0]);
}
break;
case PIPE_PRIM_LINES:
flags = DRAW_PIPE_RESET_STIPPLE;
for (i = 0; i + 1 < count; i += 2) {
idx[0] = GET_ELT(i);
idx[1] = GET_ELT(i + 1);
LINE(flags, idx[0], idx[1]);
}
break;
case PIPE_PRIM_LINE_LOOP:
case PIPE_PRIM_LINE_STRIP:
if (count >= 2) {
flags = (prim_flags & DRAW_SPLIT_BEFORE) ? 0 : DRAW_PIPE_RESET_STIPPLE;
idx[1] = GET_ELT(0);
idx[2] = idx[1];
for (i = 1; i < count; i++, flags = 0) {
idx[0] = idx[1];
idx[1] = GET_ELT(i);
LINE(flags, idx[0], idx[1]);
}
/* close the loop */
if (prim == PIPE_PRIM_LINE_LOOP && !prim_flags)
LINE(flags, idx[1], idx[2]);
}
break;
case PIPE_PRIM_TRIANGLES:
flags = DRAW_PIPE_RESET_STIPPLE | DRAW_PIPE_EDGE_FLAG_ALL;
for (i = 0; i + 2 < count; i += 3) {
idx[0] = GET_ELT(i);
idx[1] = GET_ELT(i + 1);
idx[2] = GET_ELT(i + 2);
TRIANGLE(flags, idx[0], idx[1], idx[2]);
}
break;
case PIPE_PRIM_TRIANGLE_STRIP:
if (count >= 3) {
flags = DRAW_PIPE_RESET_STIPPLE | DRAW_PIPE_EDGE_FLAG_ALL;
idx[1] = GET_ELT(0);
idx[2] = GET_ELT(1);
if (last_vertex_last) {
for (i = 0; i + 2 < count; i++) {
idx[0] = idx[1];
idx[1] = idx[2];
idx[2] = GET_ELT(i + 2);
/* always emit idx[2] last */
if (i & 1)
TRIANGLE(flags, idx[1], idx[0], idx[2]);
else
TRIANGLE(flags, idx[0], idx[1], idx[2]);
}
}
else {
for (i = 0; i + 2 < count; i++) {
idx[0] = idx[1];
idx[1] = idx[2];
idx[2] = GET_ELT(i + 2);
/* always emit idx[0] first */
if (i & 1)
TRIANGLE(flags, idx[0], idx[2], idx[1]);
else
TRIANGLE(flags, idx[0], idx[1], idx[2]);
}
}
}
break;
case PIPE_PRIM_TRIANGLE_FAN:
if (count >= 3) {
flags = DRAW_PIPE_RESET_STIPPLE | DRAW_PIPE_EDGE_FLAG_ALL;
idx[0] = GET_ELT(0);
idx[2] = GET_ELT(1);
/* idx[0] is neither the first nor the last vertex */
if (last_vertex_last) {
for (i = 0; i + 2 < count; i++) {
idx[1] = idx[2];
idx[2] = GET_ELT(i + 2);
/* always emit idx[2] last */
TRIANGLE(flags, idx[0], idx[1], idx[2]);
}
}
else {
for (i = 0; i + 2 < count; i++) {
idx[1] = idx[2];
idx[2] = GET_ELT(i + 2);
/* always emit idx[1] first */
TRIANGLE(flags, idx[1], idx[2], idx[0]);
}
}
}
break;
case PIPE_PRIM_QUADS:
if (last_vertex_last) {
for (i = 0; i + 3 < count; i += 4) {
idx[0] = GET_ELT(i);
idx[1] = GET_ELT(i + 1);
idx[2] = GET_ELT(i + 2);
idx[3] = GET_ELT(i + 3);
flags = DRAW_PIPE_RESET_STIPPLE |
DRAW_PIPE_EDGE_FLAG_0 |
DRAW_PIPE_EDGE_FLAG_2;
/* always emit idx[3] last */
TRIANGLE(flags, idx[0], idx[1], idx[3]);
flags = DRAW_PIPE_EDGE_FLAG_0 |
DRAW_PIPE_EDGE_FLAG_1;
TRIANGLE(flags, idx[1], idx[2], idx[3]);
}
}
else {
for (i = 0; i + 3 < count; i += 4) {
idx[0] = GET_ELT(i);
idx[1] = GET_ELT(i + 1);
idx[2] = GET_ELT(i + 2);
idx[3] = GET_ELT(i + 3);
flags = DRAW_PIPE_RESET_STIPPLE |
DRAW_PIPE_EDGE_FLAG_0 |
DRAW_PIPE_EDGE_FLAG_1;
/* always emit idx[3] / idx[0] first */
if (quads_flatshade_last)
TRIANGLE(flags, idx[3], idx[0], idx[1]);
else
TRIANGLE(flags, idx[0], idx[1], idx[2]);
flags = DRAW_PIPE_EDGE_FLAG_1 |
DRAW_PIPE_EDGE_FLAG_2;
if (quads_flatshade_last)
TRIANGLE(flags, idx[3], idx[1], idx[2]);
else
TRIANGLE(flags, idx[0], idx[2], idx[3]);
}
}
break;
case PIPE_PRIM_QUAD_STRIP:
if (count >= 4) {
idx[2] = GET_ELT(0);
idx[3] = GET_ELT(1);
if (last_vertex_last) {
for (i = 0; i + 3 < count; i += 2) {
idx[0] = idx[2];
idx[1] = idx[3];
idx[2] = GET_ELT(i + 2);
idx[3] = GET_ELT(i + 3);
/* always emit idx[3] last */
flags = DRAW_PIPE_RESET_STIPPLE |
DRAW_PIPE_EDGE_FLAG_0 |
DRAW_PIPE_EDGE_FLAG_2;
TRIANGLE(flags, idx[2], idx[0], idx[3]);
flags = DRAW_PIPE_EDGE_FLAG_0 |
DRAW_PIPE_EDGE_FLAG_1;
TRIANGLE(flags, idx[0], idx[1], idx[3]);
}
}
else {
for (i = 0; i + 3 < count; i += 2) {
idx[0] = idx[2];
idx[1] = idx[3];
idx[2] = GET_ELT(i + 2);
idx[3] = GET_ELT(i + 3);
flags = DRAW_PIPE_RESET_STIPPLE |
DRAW_PIPE_EDGE_FLAG_0 |
DRAW_PIPE_EDGE_FLAG_1;
/* always emit idx[3] / idx[0 first */
if (quads_flatshade_last)
TRIANGLE(flags, idx[3], idx[2], idx[0]);
else
TRIANGLE(flags, idx[0], idx[3], idx[2]);
flags = DRAW_PIPE_EDGE_FLAG_1 |
DRAW_PIPE_EDGE_FLAG_2;
if (quads_flatshade_last)
TRIANGLE(flags, idx[3], idx[0], idx[1]);
else
TRIANGLE(flags, idx[0], idx[1], idx[3]);
}
}
}
break;
case PIPE_PRIM_POLYGON:
if (count >= 3) {
ushort edge_next, edge_finish;
if (last_vertex_last) {
flags = (DRAW_PIPE_RESET_STIPPLE |
DRAW_PIPE_EDGE_FLAG_0);
if (!(prim_flags & DRAW_SPLIT_BEFORE))
flags |= DRAW_PIPE_EDGE_FLAG_2;
edge_next = DRAW_PIPE_EDGE_FLAG_0;
edge_finish =
(prim_flags & DRAW_SPLIT_AFTER) ? 0 : DRAW_PIPE_EDGE_FLAG_1;
}
else {
flags = (DRAW_PIPE_RESET_STIPPLE |
DRAW_PIPE_EDGE_FLAG_1);
if (!(prim_flags & DRAW_SPLIT_BEFORE))
flags |= DRAW_PIPE_EDGE_FLAG_0;
edge_next = DRAW_PIPE_EDGE_FLAG_1;
edge_finish =
(prim_flags & DRAW_SPLIT_AFTER) ? 0 : DRAW_PIPE_EDGE_FLAG_2;
}
idx[0] = GET_ELT(0);
idx[2] = GET_ELT(1);
for (i = 0; i + 2 < count; i++, flags = edge_next) {
idx[1] = idx[2];
idx[2] = GET_ELT(i + 2);
if (i + 3 == count)
flags |= edge_finish;
/* idx[0] is both the first and the last vertex */
if (last_vertex_last)
TRIANGLE(flags, idx[1], idx[2], idx[0]);
else
TRIANGLE(flags, idx[0], idx[1], idx[2]);
}
}
break;
case PIPE_PRIM_LINES_ADJACENCY:
flags = DRAW_PIPE_RESET_STIPPLE;
for (i = 0; i + 3 < count; i += 4) {
idx[0] = GET_ELT(i);
idx[1] = GET_ELT(i + 1);
idx[2] = GET_ELT(i + 2);
idx[3] = GET_ELT(i + 3);
LINE_ADJ(flags, idx[0], idx[1], idx[2], idx[3]);
}
break;
case PIPE_PRIM_LINE_STRIP_ADJACENCY:
if (count >= 4) {
flags = (prim_flags & DRAW_SPLIT_BEFORE) ? 0 : DRAW_PIPE_RESET_STIPPLE;
idx[1] = GET_ELT(0);
idx[2] = GET_ELT(1);
idx[3] = GET_ELT(2);
for (i = 1; i + 2 < count; i++, flags = 0) {
idx[0] = idx[1];
idx[1] = idx[2];
idx[2] = idx[3];
idx[3] = GET_ELT(i + 2);
LINE_ADJ(flags, idx[0], idx[1], idx[2], idx[3]);
}
}
break;
case PIPE_PRIM_TRIANGLES_ADJACENCY:
flags = DRAW_PIPE_RESET_STIPPLE | DRAW_PIPE_EDGE_FLAG_ALL;
for (i = 0; i + 5 < count; i += 6) {
idx[0] = GET_ELT(i);
idx[1] = GET_ELT(i + 1);
idx[2] = GET_ELT(i + 2);
idx[3] = GET_ELT(i + 3);
idx[4] = GET_ELT(i + 4);
idx[5] = GET_ELT(i + 5);
TRIANGLE_ADJ(flags, idx[0], idx[1], idx[2], idx[3], idx[4], idx[5]);
}
break;
case PIPE_PRIM_TRIANGLE_STRIP_ADJACENCY:
if (count >= 6) {
flags = DRAW_PIPE_RESET_STIPPLE | DRAW_PIPE_EDGE_FLAG_ALL;
idx[0] = GET_ELT(1);
idx[2] = GET_ELT(0);
idx[4] = GET_ELT(2);
idx[3] = GET_ELT(4);
/*
* The vertices of the i-th triangle are stored in
* idx[0,2,4] = { 2*i, 2*i+2, 2*i+4 };
*
* The adjacent vertices are stored in
* idx[1,3,5] = { 2*i-2, 2*i+6, 2*i+3 }.
*
* However, there are two exceptions:
*
* For the first triangle, idx[1] = 1;
* For the last triangle, idx[3] = 2*i+5.
*/
if (last_vertex_last) {
for (i = 0; i + 5 < count; i += 2) {
idx[1] = idx[0];
idx[0] = idx[2];
idx[2] = idx[4];
idx[4] = idx[3];
idx[3] = GET_ELT(i + ((i + 7 < count) ? 6 : 5));
idx[5] = GET_ELT(i + 3);
/*
* alternate the first two vertices (idx[0] and idx[2]) and the
* corresponding adjacent vertices (idx[3] and idx[5]) to have
* the correct orientation
*/
if (i & 2) {
TRIANGLE_ADJ(flags,
idx[2], idx[1], idx[0], idx[5], idx[4], idx[3]);
}
else {
TRIANGLE_ADJ(flags,
idx[0], idx[1], idx[2], idx[3], idx[4], idx[5]);
}
}
}
else {
for (i = 0; i + 5 < count; i += 2) {
idx[1] = idx[0];
idx[0] = idx[2];
idx[2] = idx[4];
idx[4] = idx[3];
idx[3] = GET_ELT(i + ((i + 7 < count) ? 6 : 5));
idx[5] = GET_ELT(i + 3);
/*
* alternate the last two vertices (idx[2] and idx[4]) and the
* corresponding adjacent vertices (idx[1] and idx[5]) to have
* the correct orientation
*/
if (i & 2) {
TRIANGLE_ADJ(flags,
idx[0], idx[5], idx[4], idx[3], idx[2], idx[1]);
}
else {
TRIANGLE_ADJ(flags,
idx[0], idx[1], idx[2], idx[3], idx[4], idx[5]);
}
}
}
}
break;
default:
assert(0);
break;
}
FUNC_EXIT;
}
#undef LOCAL_VARS
#undef FUNC_ENTER
#undef FUNC_EXIT
#undef LINE_ADJ
#undef TRIANGLE_ADJ
#undef FUNC
#undef FUNC_VARS
#undef GET_ELT
#undef POINT
#undef LINE
#undef TRIANGLE
|
