/**************************************************************************
*
* Copyright 2007 Tungsten Graphics, Inc., Cedar Park, Texas.
* All Rights Reserved.
*
* 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, sub license, 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 (including the
* next paragraph) 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 NON-INFRINGEMENT.
* IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS 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.
*
**************************************************************************/
/*
* Binning code for triangles
*/
#include "util/u_math.h"
#include "util/u_memory.h"
#include "util/u_rect.h"
#include "util/u_sse.h"
#include "lp_perf.h"
#include "lp_setup_context.h"
#include "lp_rast.h"
#include "lp_state_fs.h"
#include "lp_state_setup.h"
#define NUM_CHANNELS 4
#if defined(PIPE_ARCH_SSE)
#include <emmintrin.h>
#endif
static INLINE int
subpixel_snap(float a)
{
return util_iround(FIXED_ONE * a);
}
static INLINE float
fixed_to_float(int a)
{
return a * (1.0 / FIXED_ONE);
}
/* Position and area in fixed point coordinates */
struct fixed_position {
int x[4];
int y[4];
int area;
int dx01;
int dy01;
int dx20;
int dy20;
};
/**
* Alloc space for a new triangle plus the input.a0/dadx/dady arrays
* immediately after it.
* The memory is allocated from the per-scene pool, not per-tile.
* \param tri_size returns number of bytes allocated
* \param num_inputs number of fragment shader inputs
* \return pointer to triangle space
*/
struct lp_rast_triangle *
lp_setup_alloc_triangle(struct lp_scene *scene,
unsigned nr_inputs,
unsigned nr_planes,
unsigned *tri_size)
{
unsigned input_array_sz = NUM_CHANNELS * (nr_inputs + 1) * sizeof(float);
unsigned plane_sz = nr_planes * sizeof(struct lp_rast_plane);
struct lp_rast_triangle *tri;
*tri_size = (sizeof(struct lp_rast_triangle) +
3 * input_array_sz +
plane_sz);
tri = lp_scene_alloc_aligned( scene, *tri_size, 16 );
if (tri == NULL)
return NULL;
tri->inputs.stride = input_array_sz;
{
char *a = (char *)tri;
char *b = (char *)&GET_PLANES(tri)[nr_planes];
assert(b - a == *tri_size);
}
return tri;
}
void
lp_setup_print_vertex(struct lp_setup_context *setup,
const char *name,
const float (*v)[4])
{
const struct lp_setup_variant_key *key = &setup->setup.variant->key;
int i, j;
debug_printf(" wpos (%s[0]) xyzw %f %f %f %f\n",
name,
v[0][0], v[0][1], v[0][2], v[0][3]);
for (i = 0; i < key->num_inputs; i++) {
const float *in = v[key->inputs[i].src_index];
debug_printf(" in[%d] (%s[%d]) %s%s%s%s ",
i,
name, key->inputs[i].src_index,
(key->inputs[i].usage_mask & 0x1) ? "x" : " ",
(key->inputs[i].usage_mask & 0x2) ? "y" : " ",
(key->inputs[i].usage_mask & 0x4) ? "z" : " ",
(key->inputs[i].usage_mask & 0x8) ? "w" : " ");
for (j = 0; j < 4; j++)
if (key->inputs[i].usage_mask & (1<<j))
debug_printf("%.5f ", in[j]);
debug_printf("\n");
}
}
/**
* Print triangle vertex attribs (for debug).
*/
void
lp_setup_print_triangle(struct lp_setup_context *setup,
const float (*v0)[4],
const float (*v1)[4],
const float (*v2)[4])
{
debug_printf("triangle\n");
{
const float ex = v0[0][0] - v2[0][0];
const float ey = v0[0][1] - v2[0][1];
const float fx = v1[0][0] - v2[0][0];
const float fy = v1[0][1] - v2[0][1];
/* det = cross(e,f).z */
const float det = ex * fy - ey * fx;
if (det < 0.0f)
debug_printf(" - ccw\n");
else if (det > 0.0f)
debug_printf(" - cw\n");
else
debug_printf(" - zero area\n");
}
lp_setup_print_vertex(setup, "v0", v0);
lp_setup_print_vertex(setup, "v1", v1);
lp_setup_print_vertex(setup, "v2", v2);
}
#define MAX_PLANES 8
static unsigned
lp_rast_tri_tab[MAX_PLANES+1] = {
0, /* should be impossible */
LP_RAST_OP_TRIANGLE_1,
LP_RAST_OP_TRIANGLE_2,
LP_RAST_OP_TRIANGLE_3,
LP_RAST_OP_TRIANGLE_4,
LP_RAST_OP_TRIANGLE_5,
LP_RAST_OP_TRIANGLE_6,
LP_RAST_OP_TRIANGLE_7,
LP_RAST_OP_TRIANGLE_8
};
/**
* The primitive covers the whole tile- shade whole tile.
*
* \param tx, ty the tile position in tiles, not pixels
*/
static boolean
lp_setup_whole_tile(struct lp_setup_context *setup,
const struct lp_rast_shader_inputs *inputs,
int tx, int ty)
{
struct lp_scene *scene = setup->scene;
LP_COUNT(nr_fully_covered_64);
/* if variant is opaque and scissor doesn't effect the tile */
if (inputs->opaque) {
if (!scene->fb.zsbuf) {
/*
* All previous rendering will be overwritten so reset the bin.
*/
lp_scene_bin_reset( scene, tx, ty );
}
LP_COUNT(nr_shade_opaque_64);
return lp_scene_bin_cmd_with_state( scene, tx, ty,
setup->fs.stored,
LP_RAST_OP_SHADE_TILE_OPAQUE,
lp_rast_arg_inputs(inputs) );
} else {
LP_COUNT(nr_shade_64);
return lp_scene_bin_cmd_with_state( scene, tx, ty,
setup->fs.stored,
LP_RAST_OP_SHADE_TILE,
lp_rast_arg_inputs(inputs) );
}
}
/**
* Do basic setup for triangle rasterization and determine which
* framebuffer tiles are touched. Put the triangle in the scene's
* bins for the tiles which we overlap.
*/
static boolean
do_triangle_ccw(struct lp_setup_context *setup,
struct fixed_position* position,
const float (*v0)[4],
const float (*v1)[4],
const float (*v2)[4],
boolean frontfacing )
{
struct lp_scene *scene = setup->scene;
const struct lp_setup_variant_key *key = &setup->setup.variant->key;
struct lp_rast_triangle *tri;
struct lp_rast_plane *plane;
struct u_rect bbox;
unsigned tri_bytes;
int nr_planes = 3;
/* Area should always be positive here */
assert(position->area > 0);
if (0)
lp_setup_print_triangle(setup, v0, v1, v2);
if (setup->scissor_test) {
nr_planes = 7;
}
else {
nr_planes = 3;
}
/* Bounding rectangle (in pixels) */
{
/* Yes this is necessary to accurately calculate bounding boxes
* with the two fill-conventions we support. GL (normally) ends
* up needing a bottom-left fill convention, which requires
* slightly different rounding.
*/
int adj = (setup->pixel_offset != 0) ? 1 : 0;
/* Inclusive x0, exclusive x1 */
bbox.x0 = MIN3(position->x[0], position->x[1], position->x[2]) >> FIXED_ORDER;
bbox.x1 = (MAX3(position->x[0], position->x[1], position->x[2]) - 1) >> FIXED_ORDER;
/* Inclusive / exclusive depending upon adj (bottom-left or top-right) */
bbox.y0 = (MIN3(position->y[0], position->y[1], position->y[2]) + adj) >> FIXED_ORDER;
bbox.y1 = (MAX3(position->y[0], position->y[1], position->y[2]) - 1 + adj) >> FIXED_ORDER;
}
if (bbox.x1 < bbox.x0 ||
bbox.y1 < bbox.y0) {
if (0) debug_printf("empty bounding box\n");
LP_COUNT(nr_culled_tris);
return TRUE;
}
if (!u_rect_test_intersection(&setup->draw_region, &bbox)) {
if (0) debug_printf("offscreen\n");
LP_COUNT(nr_culled_tris);
return TRUE;
}
/* Can safely discard negative regions, but need to keep hold of
* information about when the triangle extends past screen
* boundaries. See trimmed_box in lp_setup_bin_triangle().
*/
bbox.x0 = MAX2(bbox.x0, 0);
bbox.y0 = MAX2(bbox.y0, 0);
tri = lp_setup_alloc_triangle(scene,
key->num_inputs,
nr_planes,
&tri_bytes);
if (!tri)
return FALSE;
#if 0
tri->v[0][0] = v0[0][0];
tri->v[1][0] = v1[0][0];
tri->v[2][0] = v2[0][0];
tri->v[0][1] = v0[0][1];
tri->v[1][1] = v1[0][1];
tri->v[2][1] = v2[0][1];
#endif
LP_COUNT(nr_tris);
/* Setup parameter interpolants:
*/
setup->setup.variant->jit_function( v0,
v1,
v2,
frontfacing,
GET_A0(&tri->inputs),
GET_DADX(&tri->inputs),
GET_DADY(&tri->inputs) );
tri->inputs.frontfacing = frontfacing;
tri->inputs.disable = FALSE;
tri->inputs.opaque = setup->fs.current.variant->opaque;
if (0)
lp_dump_setup_coef(&setup->setup.variant->key,
(const float (*)[4])GET_A0(&tri->inputs),
(const float (*)[4])GET_DADX(&tri->inputs),
(const float (*)[4])GET_DADY(&tri->inputs));
plane = GET_PLANES(tri);
#if defined(PIPE_ARCH_SSE)
{
__m128i vertx, verty;
__m128i shufx, shufy;
__m128i dcdx, dcdy, c;
__m128i unused;
__m128i dcdx_neg_mask;
__m128i dcdy_neg_mask;
__m128i dcdx_zero_mask;
__m128i top_left_flag;
__m128i c_inc_mask, c_inc;
__m128i eo, p0, p1, p2;
__m128i zero = _mm_setzero_si128();
vertx = _mm_loadu_si128((__m128i *)position->x); /* vertex x coords */
verty = _mm_loadu_si128((__m128i *)position->y); /* vertex y coords */
shufx = _mm_shuffle_epi32(vertx, _MM_SHUFFLE(3,0,2,1));
shufy = _mm_shuffle_epi32(verty, _MM_SHUFFLE(3,0,2,1));
dcdx = _mm_sub_epi32(verty, shufy);
dcdy = _mm_sub_epi32(vertx, shufx);
dcdx_neg_mask = _mm_srai_epi32(dcdx, 31);
dcdx_zero_mask = _mm_cmpeq_epi32(dcdx, zero);
dcdy_neg_mask = _mm_srai_epi32(dcdy, 31);
top_left_flag = _mm_set1_epi32((setup->pixel_offset == 0) ? ~0 : 0);
c_inc_mask = _mm_or_si128(dcdx_neg_mask,
_mm_and_si128(dcdx_zero_mask,
_mm_xor_si128(dcdy_neg_mask,
top_left_flag)));
c_inc = _mm_srli_epi32(c_inc_mask, 31);
c = _mm_sub_epi32(mm_mullo_epi32(dcdx, vertx),
mm_mullo_epi32(dcdy, verty));
c = _mm_add_epi32(c, c_inc);
/* Scale up to match c:
*/
dcdx = _mm_slli_epi32(dcdx, FIXED_ORDER);
dcdy = _mm_slli_epi32(dcdy, FIXED_ORDER);
/* Calculate trivial reject values:
*/
eo = _mm_sub_epi32(_mm_andnot_si128(dcdy_neg_mask, dcdy),
_mm_and_si128(dcdx_neg_mask, dcdx));
/* ei = _mm_sub_epi32(_mm_sub_epi32(dcdy, dcdx), eo); */
/* Pointless transpose which gets undone immediately in
* rasterization:
*/
transpose4_epi32(&c, &dcdx, &dcdy, &eo,
&p0, &p1, &p2, &unused);
_mm_store_si128((__m128i *)&plane[0], p0);
_mm_store_si128((__m128i *)&plane[1], p1);
_mm_store_si128((__m128i *)&plane[2], p2);
}
#else
{
int i;
plane[0].dcdy = position->dx01;
plane[1].dcdy = position->x[1] - position->x[2];
plane[2].dcdy = position->dx20;
plane[0].dcdx = position->dy01;
plane[1].dcdx = position->y[1] - position->y[2];
plane[2].dcdx = position->dy20;
for (i = 0; i < 3; i++) {
/* half-edge constants, will be interated over the whole render
* target.
*/
plane[i].c = plane[i].dcdx * position->x[i] - plane[i].dcdy * position->y[i];
/* correct for top-left vs. bottom-left fill convention.
*
* note that we're overloading gl_rasterization_rules to mean
* both (0.5,0.5) pixel centers *and* bottom-left filling
* convention.
*
* GL actually has a top-left filling convention, but GL's
* notion of "top" differs from gallium's...
*
* Also, sometimes (in FBO cases) GL will render upside down
* to its usual method, in which case it will probably want
* to use the opposite, top-left convention.
*/
if (plane[i].dcdx < 0) {
/* both fill conventions want this - adjust for left edges */
plane[i].c++;
}
else if (plane[i].dcdx == 0) {
if (setup->pixel_offset == 0) {
/* correct for top-left fill convention:
*/
if (plane[i].dcdy > 0) plane[i].c++;
}
else {
/* correct for bottom-left fill convention:
*/
if (plane[i].dcdy < 0) plane[i].c++;
}
}
plane[i].dcdx *= FIXED_ONE;
plane[i].dcdy *= FIXED_ONE;
/* find trivial reject offsets for each edge for a single-pixel
* sized block. These will be scaled up at each recursive level to
* match the active blocksize. Scaling in this way works best if
* the blocks are square.
*/
plane[i].eo = 0;
if (plane[i].dcdx < 0) plane[i].eo -= plane[i].dcdx;
if (plane[i].dcdy > 0) plane[i].eo += plane[i].dcdy;
}
}
#endif
if (0) {
debug_printf("p0: %08x/%08x/%08x/%08x\n",
plane[0].c,
plane[0].dcdx,
plane[0].dcdy,
plane[0].eo);
debug_printf("p1: %08x/%08x/%08x/%08x\n",
plane[1].c,
plane[1].dcdx,
plane[1].dcdy,
plane[1].eo);
debug_printf("p0: %08x/%08x/%08x/%08x\n",
plane[2].c,
plane[2].dcdx,
plane[2].dcdy,
plane[2].eo);
}
/*
* When rasterizing scissored tris, use the intersection of the
* triangle bounding box and the scissor rect to generate the
* scissor planes.
*
* This permits us to cut off the triangle "tails" that are present
* in the intermediate recursive levels caused when two of the
* triangles edges don't diverge quickly enough to trivially reject
* exterior blocks from the triangle.
*
* It's not really clear if it's worth worrying about these tails,
* but since we generate the planes for each scissored tri, it's
* free to trim them in this case.
*
* Note that otherwise, the scissor planes only vary in 'C' value,
* and even then only on state-changes. Could alternatively store
* these planes elsewhere.
*/
if (nr_planes == 7) {
const struct u_rect *scissor = &setup->scissor;
plane[3].dcdx = -1;
plane[3].dcdy = 0;
plane[3].c = 1-scissor->x0;
plane[3].eo = 1;
plane[4].dcdx = 1;
plane[4].dcdy = 0;
plane[4].c = scissor->x1+1;
plane[4].eo = 0;
plane[5].dcdx = 0;
plane[5].dcdy = 1;
plane[5].c = 1-scissor->y0;
plane[5].eo = 1;
plane[6].dcdx = 0;
plane[6].dcdy = -1;
plane[6].c = scissor->y1+1;
plane[6].eo = 0;
}
return lp_setup_bin_triangle( setup, tri, &bbox, nr_planes );
}
/*
* Round to nearest less or equal power of two of the input.
*
* Undefined if no bit set exists, so code should check against 0 first.
*/
static INLINE uint32_t
floor_pot(uint32_t n)
{
#if defined(PIPE_CC_GCC) && defined(PIPE_ARCH_X86)
if (n == 0)
return 0;
__asm__("bsr %1,%0"
: "=r" (n)
: "rm" (n));
return 1 << n;
#else
n |= (n >> 1);
n |= (n >> 2);
n |= (n >> 4);
n |= (n >> 8);
n |= (n >> 16);
return n - (n >> 1);
#endif
}
boolean
lp_setup_bin_triangle( struct lp_setup_context *setup,
struct lp_rast_triangle *tri,
const struct u_rect *bbox,
int nr_planes )
{
struct lp_scene *scene = setup->scene;
struct u_rect trimmed_box = *bbox;
int i;
/* What is the largest power-of-two boundary this triangle crosses:
*/
int dx = floor_pot((bbox->x0 ^ bbox->x1) |
(bbox->y0 ^ bbox->y1));
/* The largest dimension of the rasterized area of the triangle
* (aligned to a 4x4 grid), rounded down to the nearest power of two:
*/
int sz = floor_pot((bbox->x1 - (bbox->x0 & ~3)) |
(bbox->y1 - (bbox->y0 & ~3)));
/* Now apply scissor, etc to the bounding box. Could do this
* earlier, but it confuses the logic for tri-16 and would force
* the rasterizer to also respect scissor, etc, just for the rare
* cases where a small triangle extends beyond the scissor.
*/
u_rect_find_intersection(&setup->draw_region, &trimmed_box);
/* Determine which tile(s) intersect the triangle's bounding box
*/
if (dx < TILE_SIZE)
{
int ix0 = bbox->x0 / TILE_SIZE;
int iy0 = bbox->y0 / TILE_SIZE;
unsigned px = bbox->x0 & 63 & ~3;
unsigned py = bbox->y0 & 63 & ~3;
assert(iy0 == bbox->y1 / TILE_SIZE &&
ix0 == bbox->x1 / TILE_SIZE);
if (nr_planes == 3) {
if (sz < 4)
{
/* Triangle is contained in a single 4x4 stamp:
*/
assert(px + 4 <= TILE_SIZE);
assert(py + 4 <= TILE_SIZE);
return lp_scene_bin_cmd_with_state( scene, ix0, iy0,
setup->fs.stored,
LP_RAST_OP_TRIANGLE_3_4,
lp_rast_arg_triangle_contained(tri, px, py) );
}
if (sz < 16)
{
/* Triangle is contained in a single 16x16 block:
*/
/*
* The 16x16 block is only 4x4 aligned, and can exceed the tile
* dimensions if the triangle is 16 pixels in one dimension but 4
* in the other. So budge the 16x16 back inside the tile.
*/
px = MIN2(px, TILE_SIZE - 16);
py = MIN2(py, TILE_SIZE - 16);
assert(px + 16 <= TILE_SIZE);
assert(py + 16 <= TILE_SIZE);
return lp_scene_bin_cmd_with_state( scene, ix0, iy0,
setup->fs.stored,
LP_RAST_OP_TRIANGLE_3_16,
lp_rast_arg_triangle_contained(tri, px, py) );
}
}
else if (nr_planes == 4 && sz < 16)
{
px = MIN2(px, TILE_SIZE - 16);
py = MIN2(py, TILE_SIZE - 16);
assert(px + 16 <= TILE_SIZE);
assert(py + 16 <= TILE_SIZE);
return lp_scene_bin_cmd_with_state(scene, ix0, iy0,
setup->fs.stored,
LP_RAST_OP_TRIANGLE_4_16,
lp_rast_arg_triangle_contained(tri, px, py));
}
/* Triangle is contained in a single tile:
*/
return lp_scene_bin_cmd_with_state( scene, ix0, iy0, setup->fs.stored,
lp_rast_tri_tab[nr_planes],
lp_rast_arg_triangle(tri, (1<<nr_planes)-1) );
}
else
{
struct lp_rast_plane *plane = GET_PLANES(tri);
int c[MAX_PLANES];
int ei[MAX_PLANES];
int eo[MAX_PLANES];
int xstep[MAX_PLANES];
int ystep[MAX_PLANES];
int x, y;
int ix0 = trimmed_box.x0 / TILE_SIZE;
int iy0 = trimmed_box.y0 / TILE_SIZE;
int ix1 = trimmed_box.x1 / TILE_SIZE;
int iy1 = trimmed_box.y1 / TILE_SIZE;
for (i = 0; i < nr_planes; i++) {
c[i] = (plane[i].c +
plane[i].dcdy * iy0 * TILE_SIZE -
plane[i].dcdx * ix0 * TILE_SIZE);
ei[i] = (plane[i].dcdy -
plane[i].dcdx -
plane[i].eo) << TILE_ORDER;
eo[i] = plane[i].eo << TILE_ORDER;
xstep[i] = -(plane[i].dcdx << TILE_ORDER);
ystep[i] = plane[i].dcdy << TILE_ORDER;
}
/* Test tile-sized blocks against the triangle.
* Discard blocks fully outside the tri. If the block is fully
* contained inside the tri, bin an lp_rast_shade_tile command.
* Else, bin a lp_rast_triangle command.
*/
for (y = iy0; y <= iy1; y++)
{
boolean in = FALSE; /* are we inside the triangle? */
int cx[MAX_PLANES];
for (i = 0; i < nr_planes; i++)
cx[i] = c[i];
for (x = ix0; x <= ix1; x++)
{
int out = 0;
int partial = 0;
for (i = 0; i < nr_planes; i++) {
int planeout = cx[i] + eo[i];
int planepartial = cx[i] + ei[i] - 1;
out |= (planeout >> 31);
partial |= (planepartial >> 31) & (1<<i);
}
if (out) {
/* do nothing */
if (in)
break; /* exiting triangle, all done with this row */
LP_COUNT(nr_empty_64);
}
else if (partial) {
/* Not trivially accepted by at least one plane -
* rasterize/shade partial tile
*/
int count = util_bitcount(partial);
in = TRUE;
if (!lp_scene_bin_cmd_with_state( scene, x, y,
setup->fs.stored,
lp_rast_tri_tab[count],
lp_rast_arg_triangle(tri, partial) ))
goto fail;
LP_COUNT(nr_partially_covered_64);
}
else {
/* triangle covers the whole tile- shade whole tile */
LP_COUNT(nr_fully_covered_64);
in = TRUE;
if (!lp_setup_whole_tile(setup, &tri->inputs, x, y))
goto fail;
}
/* Iterate cx values across the region:
*/
for (i = 0; i < nr_planes; i++)
cx[i] += xstep[i];
}
/* Iterate c values down the region:
*/
for (i = 0; i < nr_planes; i++)
c[i] += ystep[i];
}
}
return TRUE;
fail:
/* Need to disable any partially binned triangle. This is easier
* than trying to locate all the triangle, shade-tile, etc,
* commands which may have been binned.
*/
tri->inputs.disable = TRUE;
return FALSE;
}
/**
* Try to draw the triangle, restart the scene on failure.
*/
static void retry_triangle_ccw( struct lp_setup_context *setup,
struct fixed_position* position,
const float (*v0)[4],
const float (*v1)[4],
const float (*v2)[4],
boolean front)
{
if (!do_triangle_ccw( setup, position, v0, v1, v2, front ))
{
if (!lp_setup_flush_and_restart(setup))
return;
if (!do_triangle_ccw( setup, position, v0, v1, v2, front ))
return;
}
}
/**
* Calculate fixed position data for a triangle
*/
static INLINE void
calc_fixed_position( struct lp_setup_context *setup,
struct fixed_position* position,
const float (*v0)[4],
const float (*v1)[4],
const float (*v2)[4])
{
position->x[0] = subpixel_snap(v0[0][0] - setup->pixel_offset);
position->x[1] = subpixel_snap(v1[0][0] - setup->pixel_offset);
position->x[2] = subpixel_snap(v2[0][0] - setup->pixel_offset);
position->x[3] = 0;
position->y[0] = subpixel_snap(v0[0][1] - setup->pixel_offset);
position->y[1] = subpixel_snap(v1[0][1] - setup->pixel_offset);
position->y[2] = subpixel_snap(v2[0][1] - setup->pixel_offset);
position->y[3] = 0;
position->dx01 = position->x[0] - position->x[1];
position->dy01 = position->y[0] - position->y[1];
position->dx20 = position->x[2] - position->x[0];
position->dy20 = position->y[2] - position->y[0];
position->area = position->dx01 * position->dy20 - position->dx20 * position->dy01;
}
/**
* Rotate a triangle, flipping its clockwise direction,
* Swaps values for xy[0] and xy[1]
*/
static INLINE void
rotate_fixed_position_01( struct fixed_position* position )
{
int x, y;
x = position->x[1];
y = position->y[1];
position->x[1] = position->x[0];
position->y[1] = position->y[0];
position->x[0] = x;
position->y[0] = y;
position->dx01 = -position->dx01;
position->dy01 = -position->dy01;
position->dx20 = position->x[2] - position->x[0];
position->dy20 = position->y[2] - position->y[0];
position->area = -position->area;
}
/**
* Rotate a triangle, flipping its clockwise direction,
* Swaps values for xy[1] and xy[2]
*/
static INLINE void
rotate_fixed_position_12( struct fixed_position* position )
{
int x, y;
x = position->x[2];
y = position->y[2];
position->x[2] = position->x[1];
position->y[2] = position->y[1];
position->x[1] = x;
position->y[1] = y;
x = position->dx01;
y = position->dy01;
position->dx01 = -position->dx20;
position->dy01 = -position->dy20;
position->dx20 = -x;
position->dy20 = -y;
position->area = -position->area;
}
/**
* Draw triangle if it's CW, cull otherwise.
*/
static void triangle_cw( struct lp_setup_context *setup,
const float (*v0)[4],
const float (*v1)[4],
const float (*v2)[4] )
{
struct fixed_position position;
calc_fixed_position(setup, &position, v0, v1, v2);
if (position.area < 0) {
if (setup->flatshade_first) {
rotate_fixed_position_12(&position);
retry_triangle_ccw(setup, &position, v0, v2, v1, !setup->ccw_is_frontface);
} else {
rotate_fixed_position_01(&position);
retry_triangle_ccw(setup, &position, v1, v0, v2, !setup->ccw_is_frontface);
}
}
}
static void triangle_ccw( struct lp_setup_context *setup,
const float (*v0)[4],
const float (*v1)[4],
const float (*v2)[4])
{
struct fixed_position position;
calc_fixed_position(setup, &position, v0, v1, v2);
if (position.area > 0)
retry_triangle_ccw(setup, &position, v0, v1, v2, setup->ccw_is_frontface);
}
/**
* Draw triangle whether it's CW or CCW.
*/
static void triangle_both( struct lp_setup_context *setup,
const float (*v0)[4],
const float (*v1)[4],
const float (*v2)[4] )
{
struct fixed_position position;
calc_fixed_position(setup, &position, v0, v1, v2);
if (0) {
assert(!util_is_inf_or_nan(v0[0][0]));
assert(!util_is_inf_or_nan(v0[0][1]));
assert(!util_is_inf_or_nan(v1[0][0]));
assert(!util_is_inf_or_nan(v1[0][1]));
assert(!util_is_inf_or_nan(v2[0][0]));
assert(!util_is_inf_or_nan(v2[0][1]));
}
if (position.area > 0)
retry_triangle_ccw( setup, &position, v0, v1, v2, setup->ccw_is_frontface );
else if (position.area < 0) {
if (setup->flatshade_first) {
rotate_fixed_position_12( &position );
retry_triangle_ccw( setup, &position, v0, v2, v1, !setup->ccw_is_frontface );
} else {
rotate_fixed_position_01( &position );
retry_triangle_ccw( setup, &position, v1, v0, v2, !setup->ccw_is_frontface );
}
}
}
static void triangle_nop( struct lp_setup_context *setup,
const float (*v0)[4],
const float (*v1)[4],
const float (*v2)[4] )
{
}
void
lp_setup_choose_triangle( struct lp_setup_context *setup )
{
switch (setup->cullmode) {
case PIPE_FACE_NONE:
setup->triangle = triangle_both;
break;
case PIPE_FACE_BACK:
setup->triangle = setup->ccw_is_frontface ? triangle_ccw : triangle_cw;
break;
case PIPE_FACE_FRONT:
setup->triangle = setup->ccw_is_frontface ? triangle_cw : triangle_ccw;
break;
default:
setup->triangle = triangle_nop;
break;
}
}