/************************************************************************** * * 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 "lp_perf.h" #include "lp_setup_context.h" #include "lp_rast.h" #include "lp_state_fs.h" #define NUM_CHANNELS 4 struct tri_info { float pixel_offset; /* fixed point vertex coordinates */ int x[3]; int y[3]; /* float x,y deltas - all from the original coordinates */ float dy01, dy20; float dx01, dx20; float oneoverarea; const float (*v0)[4]; const float (*v1)[4]; const float (*v2)[4]; boolean frontfacing; }; static const int step_scissor_minx[16] = { 0, 1, 0, 1, 2, 3, 2, 3, 0, 1, 0, 1, 2, 3, 2, 3 }; static const int step_scissor_maxx[16] = { 0, -1, 0, -1, -2, -3, -2, -3, 0, -1, 0, -1, -2, -3, -2, -3 }; static const int step_scissor_miny[16] = { 0, 0, 1, 1, 0, 0, 1, 1, 2, 2, 3, 3, 2, 2, 3, 3 }; static const int step_scissor_maxy[16] = { 0, 0, -1, -1, 0, 0, -1, -1, -2, -2, -3, -3, -2, -2, -3, -3 }; 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); } /** * Compute a0 for a constant-valued coefficient (GL_FLAT shading). */ static void constant_coef( struct lp_rast_triangle *tri, unsigned slot, const float value, unsigned i ) { tri->inputs.a0[slot][i] = value; tri->inputs.dadx[slot][i] = 0.0f; tri->inputs.dady[slot][i] = 0.0f; } static void linear_coef( struct lp_rast_triangle *tri, const struct tri_info *info, unsigned slot, unsigned vert_attr, unsigned i) { float a0 = info->v0[vert_attr][i]; float a1 = info->v1[vert_attr][i]; float a2 = info->v2[vert_attr][i]; float da01 = a0 - a1; float da20 = a2 - a0; float dadx = (da01 * info->dy20 - info->dy01 * da20) * info->oneoverarea; float dady = (da20 * info->dx01 - info->dx20 * da01) * info->oneoverarea; tri->inputs.dadx[slot][i] = dadx; tri->inputs.dady[slot][i] = dady; /* calculate a0 as the value which would be sampled for the * fragment at (0,0), taking into account that we want to sample at * pixel centers, in other words (0.5, 0.5). * * this is neat but unfortunately not a good way to do things for * triangles with very large values of dadx or dady as it will * result in the subtraction and re-addition from a0 of a very * large number, which means we'll end up loosing a lot of the * fractional bits and precision from a0. the way to fix this is * to define a0 as the sample at a pixel center somewhere near vmin * instead - i'll switch to this later. */ tri->inputs.a0[slot][i] = (a0 - (dadx * (info->v0[0][0] - info->pixel_offset) + dady * (info->v0[0][1] - info->pixel_offset))); } /** * Compute a0, dadx and dady for a perspective-corrected interpolant, * for a triangle. * We basically multiply the vertex value by 1/w before computing * the plane coefficients (a0, dadx, dady). * Later, when we compute the value at a particular fragment position we'll * divide the interpolated value by the interpolated W at that fragment. */ static void perspective_coef( struct lp_rast_triangle *tri, const struct tri_info *info, unsigned slot, unsigned vert_attr, unsigned i) { /* premultiply by 1/w (v[0][3] is always 1/w): */ float a0 = info->v0[vert_attr][i] * info->v0[0][3]; float a1 = info->v1[vert_attr][i] * info->v1[0][3]; float a2 = info->v2[vert_attr][i] * info->v2[0][3]; float da01 = a0 - a1; float da20 = a2 - a0; float dadx = (da01 * info->dy20 - info->dy01 * da20) * info->oneoverarea; float dady = (da20 * info->dx01 - info->dx20 * da01) * info->oneoverarea; tri->inputs.dadx[slot][i] = dadx; tri->inputs.dady[slot][i] = dady; tri->inputs.a0[slot][i] = (a0 - (dadx * (info->v0[0][0] - info->pixel_offset) + dady * (info->v0[0][1] - info->pixel_offset))); } /** * Special coefficient setup for gl_FragCoord. * X and Y are trivial * Z and W are copied from position_coef which should have already been computed. * We could do a bit less work if we'd examine gl_FragCoord's swizzle mask. */ static void setup_fragcoord_coef(struct lp_rast_triangle *tri, const struct tri_info *info, unsigned slot, unsigned usage_mask) { /*X*/ if (usage_mask & TGSI_WRITEMASK_X) { tri->inputs.a0[slot][0] = 0.0; tri->inputs.dadx[slot][0] = 1.0; tri->inputs.dady[slot][0] = 0.0; } /*Y*/ if (usage_mask & TGSI_WRITEMASK_Y) { tri->inputs.a0[slot][1] = 0.0; tri->inputs.dadx[slot][1] = 0.0; tri->inputs.dady[slot][1] = 1.0; } /*Z*/ if (usage_mask & TGSI_WRITEMASK_Z) { linear_coef(tri, info, slot, 0, 2); } /*W*/ if (usage_mask & TGSI_WRITEMASK_W) { linear_coef(tri, info, slot, 0, 3); } } /** * Setup the fragment input attribute with the front-facing value. * \param frontface is the triangle front facing? */ static void setup_facing_coef( struct lp_rast_triangle *tri, unsigned slot, boolean frontface, unsigned usage_mask) { /* convert TRUE to 1.0 and FALSE to -1.0 */ if (usage_mask & TGSI_WRITEMASK_X) constant_coef( tri, slot, 2.0f * frontface - 1.0f, 0 ); if (usage_mask & TGSI_WRITEMASK_Y) constant_coef( tri, slot, 0.0f, 1 ); /* wasted */ if (usage_mask & TGSI_WRITEMASK_Z) constant_coef( tri, slot, 0.0f, 2 ); /* wasted */ if (usage_mask & TGSI_WRITEMASK_W) constant_coef( tri, slot, 0.0f, 3 ); /* wasted */ } /** * Compute the tri->coef[] array dadx, dady, a0 values. */ static void setup_tri_coefficients( struct lp_setup_context *setup, struct lp_rast_triangle *tri, const struct tri_info *info) { unsigned fragcoord_usage_mask = TGSI_WRITEMASK_XYZ; unsigned slot; /* setup interpolation for all the remaining attributes: */ for (slot = 0; slot < setup->fs.nr_inputs; slot++) { unsigned vert_attr = setup->fs.input[slot].src_index; unsigned usage_mask = setup->fs.input[slot].usage_mask; unsigned i; switch (setup->fs.input[slot].interp) { case LP_INTERP_CONSTANT: if (setup->flatshade_first) { for (i = 0; i < NUM_CHANNELS; i++) if (usage_mask & (1 << i)) constant_coef(tri, slot+1, info->v0[vert_attr][i], i); } else { for (i = 0; i < NUM_CHANNELS; i++) if (usage_mask & (1 << i)) constant_coef(tri, slot+1, info->v2[vert_attr][i], i); } break; case LP_INTERP_LINEAR: for (i = 0; i < NUM_CHANNELS; i++) if (usage_mask & (1 << i)) linear_coef(tri, info, slot+1, vert_attr, i); break; case LP_INTERP_PERSPECTIVE: for (i = 0; i < NUM_CHANNELS; i++) if (usage_mask & (1 << i)) perspective_coef(tri, info, slot+1, vert_attr, i); fragcoord_usage_mask |= TGSI_WRITEMASK_W; break; case LP_INTERP_POSITION: /* * The generated pixel interpolators will pick up the coeffs from * slot 0, so all need to ensure that the usage mask is covers all * usages. */ fragcoord_usage_mask |= usage_mask; break; case LP_INTERP_FACING: setup_facing_coef(tri, slot+1, info->frontfacing, usage_mask); break; default: assert(0); } } /* The internal position input is in slot zero: */ setup_fragcoord_coef(tri, info, 0, fragcoord_usage_mask); } /** * 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 nr_inputs number of fragment shader inputs * \return pointer to triangle space */ static INLINE struct lp_rast_triangle * 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); struct lp_rast_triangle *tri; unsigned tri_bytes, bytes; char *inputs; assert(sizeof(*tri) % 16 == 0); tri_bytes = align(Offset(struct lp_rast_triangle, plane[nr_planes]), 16); bytes = tri_bytes + (3 * input_array_sz); tri = lp_scene_alloc_aligned( scene, bytes, 16 ); if (tri) { inputs = ((char *)tri) + tri_bytes; tri->inputs.a0 = (float (*)[4]) inputs; tri->inputs.dadx = (float (*)[4]) (inputs + input_array_sz); tri->inputs.dady = (float (*)[4]) (inputs + 2 * input_array_sz); *tri_size = bytes; } return tri; } /** * Print triangle vertex attribs (for debug). */ static void print_triangle(struct lp_setup_context *setup, const float (*v1)[4], const float (*v2)[4], const float (*v3)[4]) { uint i; debug_printf("llvmpipe triangle\n"); for (i = 0; i < 1 + setup->fs.nr_inputs; i++) { debug_printf(" v1[%d]: %f %f %f %f\n", i, v1[i][0], v1[i][1], v1[i][2], v1[i][3]); } for (i = 0; i < 1 + setup->fs.nr_inputs; i++) { debug_printf(" v2[%d]: %f %f %f %f\n", i, v2[i][0], v2[i][1], v2[i][2], v2[i][3]); } for (i = 0; i < 1 + setup->fs.nr_inputs; i++) { debug_printf(" v3[%d]: %f %f %f %f\n", i, v3[i][0], v3[i][1], v3[i][2], v3[i][3]); } } lp_rast_cmd lp_rast_tri_tab[8] = { NULL, /* should be impossible */ lp_rast_triangle_1, lp_rast_triangle_2, lp_rast_triangle_3, lp_rast_triangle_4, lp_rast_triangle_5, lp_rast_triangle_6, lp_rast_triangle_7 }; /** * 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 void do_triangle_ccw(struct lp_setup_context *setup, const float (*v1)[4], const float (*v2)[4], const float (*v3)[4], boolean frontfacing ) { struct lp_scene *scene = lp_setup_get_current_scene(setup); struct lp_fragment_shader_variant *variant = setup->fs.current.variant; struct lp_rast_triangle *tri; struct tri_info info; int area; int minx, maxx, miny, maxy; int ix0, ix1, iy0, iy1; unsigned tri_bytes; int i; int nr_planes = 3; if (0) print_triangle(setup, v1, v2, v3); if (setup->scissor_test) { nr_planes = 7; } else { nr_planes = 3; } tri = alloc_triangle(scene, setup->fs.nr_inputs, nr_planes, &tri_bytes); if (!tri) return; #ifdef DEBUG tri->v[0][0] = v1[0][0]; tri->v[1][0] = v2[0][0]; tri->v[2][0] = v3[0][0]; tri->v[0][1] = v1[0][1]; tri->v[1][1] = v2[0][1]; tri->v[2][1] = v3[0][1]; #endif /* x/y positions in fixed point */ info.x[0] = subpixel_snap(v1[0][0] - setup->pixel_offset); info.x[1] = subpixel_snap(v2[0][0] - setup->pixel_offset); info.x[2] = subpixel_snap(v3[0][0] - setup->pixel_offset); info.y[0] = subpixel_snap(v1[0][1] - setup->pixel_offset); info.y[1] = subpixel_snap(v2[0][1] - setup->pixel_offset); info.y[2] = subpixel_snap(v3[0][1] - setup->pixel_offset); tri->plane[0].dcdy = info.x[0] - info.x[1]; tri->plane[1].dcdy = info.x[1] - info.x[2]; tri->plane[2].dcdy = info.x[2] - info.x[0]; tri->plane[0].dcdx = info.y[0] - info.y[1]; tri->plane[1].dcdx = info.y[1] - info.y[2]; tri->plane[2].dcdx = info.y[2] - info.y[0]; area = (tri->plane[0].dcdy * tri->plane[2].dcdx - tri->plane[2].dcdy * tri->plane[0].dcdx); LP_COUNT(nr_tris); /* Cull non-ccw and zero-sized triangles. * * XXX: subject to overflow?? */ if (area <= 0) { lp_scene_putback_data( scene, tri_bytes ); LP_COUNT(nr_culled_tris); return; } /* 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; minx = (MIN3(info.x[0], info.x[1], info.x[2]) + (FIXED_ONE-1)) >> FIXED_ORDER; maxx = (MAX3(info.x[0], info.x[1], info.x[2]) + (FIXED_ONE-1)) >> FIXED_ORDER; miny = (MIN3(info.y[0], info.y[1], info.y[2]) + (FIXED_ONE-1) + adj) >> FIXED_ORDER; maxy = (MAX3(info.y[0], info.y[1], info.y[2]) + (FIXED_ONE-1) + adj) >> FIXED_ORDER; } if (setup->scissor_test) { minx = MAX2(minx, setup->scissor.current.minx); maxx = MIN2(maxx, setup->scissor.current.maxx); miny = MAX2(miny, setup->scissor.current.miny); maxy = MIN2(maxy, setup->scissor.current.maxy); } else { minx = MAX2(minx, 0); miny = MAX2(miny, 0); maxx = MIN2(maxx, scene->fb.width); maxy = MIN2(maxy, scene->fb.height); } if (miny >= maxy || minx >= maxx) { lp_scene_putback_data( scene, tri_bytes ); LP_COUNT(nr_culled_tris); return; } /* */ info.pixel_offset = setup->pixel_offset; info.v0 = v1; info.v1 = v2; info.v2 = v3; info.dx01 = info.v0[0][0] - info.v1[0][0]; info.dx20 = info.v2[0][0] - info.v0[0][0]; info.dy01 = info.v0[0][1] - info.v1[0][1]; info.dy20 = info.v2[0][1] - info.v0[0][1]; info.oneoverarea = 1.0 / (info.dx01 * info.dy20 - info.dx20 * info.dy01); info.frontfacing = frontfacing; /* Setup parameter interpolants: */ setup_tri_coefficients( setup, tri, &info ); tri->inputs.facing = frontfacing ? 1.0F : -1.0F; tri->inputs.state = setup->fs.stored; for (i = 0; i < 3; i++) { struct lp_rast_plane *plane = &tri->plane[i]; /* half-edge constants, will be interated over the whole render * target. */ plane->c = plane->dcdx * info.x[i] - plane->dcdy * info.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->dcdx < 0) { /* both fill conventions want this - adjust for left edges */ plane->c++; } else if (plane->dcdx == 0) { if (setup->pixel_offset == 0) { /* correct for top-left fill convention: */ if (plane->dcdy > 0) plane->c++; } else { /* correct for bottom-left fill convention: */ if (plane->dcdy < 0) plane->c++; } } plane->dcdx *= FIXED_ONE; plane->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->eo = 0; if (plane->dcdx < 0) plane->eo -= plane->dcdx; if (plane->dcdy > 0) plane->eo += plane->dcdy; /* Calculate trivial accept offsets from the above. */ plane->ei = plane->dcdy - plane->dcdx - plane->eo; plane->step = tri->step[i]; /* Fill in the inputs.step[][] arrays. * We've manually unrolled some loops here. */ #define SETUP_STEP(j, x, y) \ tri->step[i][j] = y * plane->dcdy - x * plane->dcdx SETUP_STEP(0, 0, 0); SETUP_STEP(1, 1, 0); SETUP_STEP(2, 0, 1); SETUP_STEP(3, 1, 1); SETUP_STEP(4, 2, 0); SETUP_STEP(5, 3, 0); SETUP_STEP(6, 2, 1); SETUP_STEP(7, 3, 1); SETUP_STEP(8, 0, 2); SETUP_STEP(9, 1, 2); SETUP_STEP(10, 0, 3); SETUP_STEP(11, 1, 3); SETUP_STEP(12, 2, 2); SETUP_STEP(13, 3, 2); SETUP_STEP(14, 2, 3); SETUP_STEP(15, 3, 3); #undef STEP } /* * 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) { tri->plane[3].step = step_scissor_minx; tri->plane[3].dcdx = -1; tri->plane[3].dcdy = 0; tri->plane[3].c = 1-minx; tri->plane[3].ei = 0; tri->plane[3].eo = 1; tri->plane[4].step = step_scissor_maxx; tri->plane[4].dcdx = 1; tri->plane[4].dcdy = 0; tri->plane[4].c = maxx; tri->plane[4].ei = -1; tri->plane[4].eo = 0; tri->plane[5].step = step_scissor_miny; tri->plane[5].dcdx = 0; tri->plane[5].dcdy = 1; tri->plane[5].c = 1-miny; tri->plane[5].ei = 0; tri->plane[5].eo = 1; tri->plane[6].step = step_scissor_maxy; tri->plane[6].dcdx = 0; tri->plane[6].dcdy = -1; tri->plane[6].c = maxy; tri->plane[6].ei = -1; tri->plane[6].eo = 0; } /* * All fields of 'tri' are now set. The remaining code here is * concerned with binning. */ /* Convert to tile coordinates, and inclusive ranges: */ ix0 = minx / TILE_SIZE; iy0 = miny / TILE_SIZE; ix1 = (maxx-1) / TILE_SIZE; iy1 = (maxy-1) / TILE_SIZE; /* * Clamp to framebuffer size */ assert(ix0 == MAX2(ix0, 0)); assert(iy0 == MAX2(iy0, 0)); assert(ix1 == MIN2(ix1, scene->tiles_x - 1)); assert(iy1 == MIN2(iy1, scene->tiles_y - 1)); /* Determine which tile(s) intersect the triangle's bounding box */ if (iy0 == iy1 && ix0 == ix1) { /* Triangle is contained in a single tile: */ lp_scene_bin_command( scene, ix0, iy0, lp_rast_tri_tab[nr_planes], lp_rast_arg_triangle(tri, (1<plane[i].c + tri->plane[i].dcdy * iy0 * TILE_SIZE - tri->plane[i].dcdx * ix0 * TILE_SIZE); ei[i] = tri->plane[i].ei << TILE_ORDER; eo[i] = tri->plane[i].eo << TILE_ORDER; xstep[i] = -(tri->plane[i].dcdx << TILE_ORDER); ystep[i] = tri->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[7]; 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<opaque && !setup->fb.zsbuf) { lp_scene_bin_reset( scene, x, y ); } lp_scene_bin_command( scene, x, y, lp_rast_shade_tile, lp_rast_arg_inputs(&tri->inputs) ); } /* 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]; } } } /** * 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] ) { do_triangle_ccw( setup, v1, v0, v2, !setup->ccw_is_frontface ); } /** * Draw triangle if it's CCW, cull otherwise. */ static void triangle_ccw( struct lp_setup_context *setup, const float (*v0)[4], const float (*v1)[4], const float (*v2)[4] ) { do_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] ) { /* edge vectors e = v0 - v2, f = v1 - v2 */ 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 */ if (ex * fy - ey * fx < 0.0f) triangle_ccw( setup, v0, v1, v2 ); else triangle_cw( setup, v0, v1, v2 ); } 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; } }