/************************************************************************** * * 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); } /** * 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, 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; int x[4]; int y[4]; struct u_rect bbox; unsigned tri_bytes; int nr_planes = 3; if (0) lp_setup_print_triangle(setup, v0, v1, v2); if (setup->scissor_test) { nr_planes = 7; } else { nr_planes = 3; } /* x/y positions in fixed point */ x[0] = subpixel_snap(v0[0][0] - setup->pixel_offset); x[1] = subpixel_snap(v1[0][0] - setup->pixel_offset); x[2] = subpixel_snap(v2[0][0] - setup->pixel_offset); x[3] = 0; y[0] = subpixel_snap(v0[0][1] - setup->pixel_offset); y[1] = subpixel_snap(v1[0][1] - setup->pixel_offset); y[2] = subpixel_snap(v2[0][1] - setup->pixel_offset); y[3] = 0; /* 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; bbox.x0 = (MIN3(x[0], x[1], x[2]) + (FIXED_ONE-1)) >> FIXED_ORDER; bbox.x1 = (MAX3(x[0], x[1], x[2]) + (FIXED_ONE-1)) >> FIXED_ORDER; bbox.y0 = (MIN3(y[0], y[1], y[2]) + (FIXED_ONE-1) + adj) >> FIXED_ORDER; bbox.y1 = (MAX3(y[0], y[1], y[2]) + (FIXED_ONE-1) + adj) >> FIXED_ORDER; /* Inclusive coordinates: */ bbox.x1--; bbox.y1--; } 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 *)x); /* vertex x coords */ verty = _mm_loadu_si128((__m128i *)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 = x[0] - x[1]; plane[1].dcdy = x[1] - x[2]; plane[2].dcdy = x[2] - x[0]; plane[0].dcdx = y[0] - y[1]; plane[1].dcdx = y[1] - y[2]; plane[2].dcdx = y[2] - y[0]; for (i = 0; i < 3; i++) { /* half-edge constants, will be interated over the whole render * target. */ plane[i].c = plane[i].dcdx * x[i] - plane[i].dcdy * 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, const float (*v0)[4], const float (*v1)[4], const float (*v2)[4], boolean front) { if (!do_triangle_ccw( setup, v0, v1, v2, front )) { if (!lp_setup_flush_and_restart(setup)) return; if (!do_triangle_ccw( setup, v0, v1, v2, front )) return; } } static INLINE float calc_area(const float (*v0)[4], const float (*v1)[4], const float (*v2)[4]) { float dx01 = v0[0][0] - v1[0][0]; float dy01 = v0[0][1] - v1[0][1]; float dx20 = v2[0][0] - v0[0][0]; float dy20 = v2[0][1] - v0[0][1]; return dx01 * dy20 - dx20 * dy01; } /** * 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] ) { float area = calc_area(v0, v1, v2); if (area < 0.0f) retry_triangle_ccw(setup, v0, v2, v1, !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]) { float area = calc_area(v0, v1, v2); if (area > 0.0f) retry_triangle_ccw(setup, 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] ) { float area = calc_area(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])); assert(!util_is_inf_or_nan(area)); } if (area > 0.0f) retry_triangle_ccw( setup, v0, v1, v2, setup->ccw_is_frontface ); else if (area < 0.0f) retry_triangle_ccw( setup, v0, v2, v1, !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; } }