/************************************************************************** * * 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. * **************************************************************************/ /* Authors: Keith Whitwell */ #include "imports.h" #include "macros.h" #include "sp_context.h" #include "sp_prim.h" #include "sp_tile.h" /** * Triangle edge info */ struct edge { GLfloat dx; /* X(v1) - X(v0), used only during setup */ GLfloat dy; /* Y(v1) - Y(v0), used only during setup */ GLfloat dxdy; /* dx/dy */ GLfloat sx; /* first sample point x coord */ GLfloat sy; GLint lines; /* number of lines on this edge */ }; /** * Triangle setup info (derived from prim_stage). * Also used for line drawing (taking some liberties). */ struct setup_stage { struct prim_stage stage; /**< This must be first */ /* Vertices are just an array of floats making up each attribute in * turn. Currently fixed at 4 floats, but should change in time. * Codegen will help cope with this. */ const struct vertex_header *vmax; const struct vertex_header *vmid; const struct vertex_header *vmin; const struct vertex_header *vprovoke; struct edge ebot; struct edge etop; struct edge emaj; GLfloat oneoverarea; struct setup_coefficient coef[FRAG_ATTRIB_MAX]; struct quad_header quad; struct { GLint left[2]; /**< [0] = row0, [1] = row1 */ GLint right[2]; GLint y; GLuint y_flags; GLuint mask; /**< mask of MASK_BOTTOM/TOP_LEFT/RIGHT bits */ } span; }; /** * Basically a cast wrapper. */ static inline struct setup_stage *setup_stage( struct prim_stage *stage ) { return (struct setup_stage *)stage; } /** * Given an X or Y coordinate, return the block/quad coordinate that it * belongs to. */ static inline GLint block( GLint x ) { return x & ~1; } static void setup_begin( struct prim_stage *stage ) { setup_stage(stage)->quad.nr_attrs = stage->softpipe->nr_frag_attrs; } /** * Run shader on a quad/block. */ static void run_shader_block( struct setup_stage *setup, GLint x, GLint y, GLuint mask ) { setup->quad.x0 = x; setup->quad.y0 = y; setup->quad.mask = mask; quad_shade( setup->stage.softpipe, &setup->quad ); } /** * Compute mask which indicates which pixels in the 2x2 quad are actually inside * the triangle's bounds. * * this is pretty nasty... may need to rework flush_spans again to * fix it, if possible. */ static GLuint calculate_mask( struct setup_stage *setup, GLint x ) { GLuint mask = 0; if (x >= setup->span.left[0] && x < setup->span.right[0]) mask |= MASK_BOTTOM_LEFT; if (x >= setup->span.left[1] && x < setup->span.right[1]) mask |= MASK_TOP_LEFT; if (x+1 >= setup->span.left[0] && x+1 < setup->span.right[0]) mask |= MASK_BOTTOM_RIGHT; if (x+1 >= setup->span.left[1] && x+1 < setup->span.right[1]) mask |= MASK_TOP_RIGHT; return mask; } /** * Render a horizontal span of quads */ static void flush_spans( struct setup_stage *setup ) { GLint minleft, maxright; GLint x; switch (setup->span.y_flags) { case 3: minleft = MIN2(setup->span.left[0], setup->span.left[1]); maxright = MAX2(setup->span.right[0], setup->span.right[1]); break; case 1: minleft = setup->span.left[0]; maxright = setup->span.right[0]; break; case 2: minleft = setup->span.left[1]; maxright = setup->span.right[1]; break; default: return; } for (x = block(minleft); x <= block(maxright); ) { run_shader_block( setup, x, setup->span.y, calculate_mask( setup, x ) ); x += 2; } setup->span.y = 0; setup->span.y_flags = 0; setup->span.right[0] = 0; setup->span.right[1] = 0; } static GLboolean setup_sort_vertices( struct setup_stage *setup, const struct prim_header *prim ) { const struct vertex_header *v0 = prim->v[0]; const struct vertex_header *v1 = prim->v[1]; const struct vertex_header *v2 = prim->v[2]; setup->vprovoke = v2; /* determine bottom to top order of vertices */ { GLfloat y0 = v0->data[0][1]; GLfloat y1 = v1->data[0][1]; GLfloat y2 = v2->data[0][1]; if (y0 <= y1) { if (y1 <= y2) { /* y0<=y1<=y2 */ setup->vmin = v0; setup->vmid = v1; setup->vmax = v2; } else if (y2 <= y0) { /* y2<=y0<=y1 */ setup->vmin = v2; setup->vmid = v0; setup->vmax = v1; } else { /* y0<=y2<=y1 */ setup->vmin = v0; setup->vmid = v2; setup->vmax = v1; } } else { if (y0 <= y2) { /* y1<=y0<=y2 */ setup->vmin = v1; setup->vmid = v0; setup->vmax = v2; } else if (y2 <= y1) { /* y2<=y1<=y0 */ setup->vmin = v2; setup->vmid = v1; setup->vmax = v0; } else { /* y1<=y2<=y0 */ setup->vmin = v1; setup->vmid = v2; setup->vmax = v0; } } } setup->ebot.dx = setup->vmid->data[0][0] - setup->vmin->data[0][0]; setup->ebot.dy = setup->vmid->data[0][1] - setup->vmin->data[0][1]; setup->emaj.dx = setup->vmax->data[0][0] - setup->vmin->data[0][0]; setup->emaj.dy = setup->vmax->data[0][1] - setup->vmin->data[0][1]; setup->etop.dx = setup->vmax->data[0][0] - setup->vmid->data[0][0]; setup->etop.dy = setup->vmax->data[0][1] - setup->vmid->data[0][1]; /* xxx: may need to adjust this sign according to the if-tree * above: * * XXX: this is like 'det', but calculated from screen coords?? */ { const GLfloat area = (setup->emaj.dx * setup->ebot.dy - setup->ebot.dx * setup->emaj.dy); setup->oneoverarea = 1.0 / area; } /* XXX need to know if this is a front or back-facing triangle: * - the GLSL gl_FrontFacing fragment attribute (bool) * - two-sided stencil test */ setup->quad.facing = 0; _mesa_printf("%s one-over-area %f\n", __FUNCTION__, setup->oneoverarea ); return GL_TRUE; } /** * Compute a0 for a constant-valued coefficient (GL_FLAT shading). */ static void const_coeff( struct setup_stage *setup, GLuint slot, GLuint i ) { setup->coef[slot].dadx[i] = 0; setup->coef[slot].dady[i] = 0; /* need provoking vertex info! */ setup->coef[slot].a0[i] = setup->vprovoke->data[slot][i]; } /** * Compute a0, dadx and dady for a linearly interpolated coefficient, * for a triangle. */ static void tri_linear_coeff( struct setup_stage *setup, GLuint slot, GLuint i) { GLfloat botda = setup->vmid->data[slot][i] - setup->vmin->data[slot][i]; GLfloat majda = setup->vmax->data[slot][i] - setup->vmin->data[slot][i]; GLfloat a = setup->ebot.dy * majda - botda * setup->emaj.dy; GLfloat b = setup->emaj.dx * botda - majda * setup->ebot.dx; setup->coef[slot].dadx[i] = a * setup->oneoverarea; setup->coef[slot].dady[i] = b * setup->oneoverarea; /* 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. */ setup->coef[slot].a0[i] = (setup->vmin->data[slot][i] - (setup->coef[slot].dadx[i] * (setup->vmin->data[0][0] - 0.5) + setup->coef[slot].dady[i] * (setup->vmin->data[0][1] - 0.5))); _mesa_printf("attr[%d].%c: %f dx:%f dy:%f\n", slot, "xyzw"[i], setup->coef[slot].a0[i], setup->coef[slot].dadx[i], setup->coef[slot].dady[i]); } /** * Compute a0, dadx and dady for a perspective-corrected interpolant, * for a triangle. */ static void tri_persp_coeff( struct setup_stage *setup, GLuint slot, GLuint i ) { /* premultiply by 1/w: */ GLfloat mina = setup->vmin->data[slot][i] * setup->vmin->data[0][3]; GLfloat mida = setup->vmid->data[slot][i] * setup->vmid->data[0][3]; GLfloat maxa = setup->vmax->data[slot][i] * setup->vmax->data[0][3]; GLfloat botda = mida - mina; GLfloat majda = maxa - mina; GLfloat a = setup->ebot.dy * majda - botda * setup->emaj.dy; GLfloat b = setup->emaj.dx * botda - majda * setup->ebot.dx; setup->coef[slot].dadx[i] = a * setup->oneoverarea; setup->coef[slot].dady[i] = b * setup->oneoverarea; setup->coef[slot].a0[i] = (mina - (setup->coef[slot].dadx[i] * (setup->vmin->data[0][0] - 0.5) + setup->coef[slot].dady[i] * (setup->vmin->data[0][1] - 0.5))); } /** * Compute the setup->coef[] array dadx, dady, a0 values. * Must be called after setup->vmin,vmid,vmax,vprovoke are initialized. */ static void setup_tri_coefficients( struct setup_stage *setup ) { const enum interp_mode *interp = setup->stage.softpipe->interp; GLuint slot, j; /* z and w are done by linear interpolation: */ tri_linear_coeff(setup, 0, 2); tri_linear_coeff(setup, 0, 3); /* setup interpolation for all the remaining attributes: */ for (slot = 1; slot < setup->quad.nr_attrs; slot++) { switch (interp[slot]) { case INTERP_CONSTANT: for (j = 0; j < NUM_CHANNELS; j++) const_coeff(setup, slot, j); break; case INTERP_LINEAR: for (j = 0; j < NUM_CHANNELS; j++) tri_linear_coeff(setup, slot, j); break; case INTERP_PERSPECTIVE: for (j = 0; j < NUM_CHANNELS; j++) tri_persp_coeff(setup, slot, j); break; } } } static void setup_tri_edges( struct setup_stage *setup ) { GLfloat vmin_x = setup->vmin->data[0][0] + 0.5; GLfloat vmid_x = setup->vmid->data[0][0] + 0.5; GLfloat vmin_y = setup->vmin->data[0][1] - 0.5; GLfloat vmid_y = setup->vmid->data[0][1] - 0.5; GLfloat vmax_y = setup->vmax->data[0][1] - 0.5; setup->emaj.sy = ceilf(vmin_y); setup->emaj.lines = (GLint) ceilf(vmax_y - setup->emaj.sy); setup->emaj.dxdy = setup->emaj.dx / setup->emaj.dy; setup->emaj.sx = vmin_x + (setup->emaj.sy - vmin_y) * setup->emaj.dxdy; setup->etop.sy = ceilf(vmid_y); setup->etop.lines = (GLint) ceilf(vmax_y - setup->etop.sy); setup->etop.dxdy = setup->etop.dx / setup->etop.dy; setup->etop.sx = vmid_x + (setup->etop.sy - vmid_y) * setup->etop.dxdy; setup->ebot.sy = ceilf(vmin_y); setup->ebot.lines = (GLint) ceilf(vmid_y - setup->ebot.sy); setup->ebot.dxdy = setup->ebot.dx / setup->ebot.dy; setup->ebot.sx = vmin_x + (setup->ebot.sy - vmin_y) * setup->ebot.dxdy; } /** * Render the upper or lower half of a triangle. * Scissoring is applied here too. */ static void subtriangle( struct setup_stage *setup, struct edge *eleft, struct edge *eright, GLuint lines ) { GLint y, start_y, finish_y; GLint sy = (GLint)eleft->sy; assert((GLint)eleft->sy == (GLint) eright->sy); assert((GLint)eleft->sy >= 0); /* catch bug in x64? */ /* scissor y: */ if (setup->stage.softpipe->setup.scissor) { start_y = sy; finish_y = start_y + lines; if (start_y < setup->stage.softpipe->scissor.miny) start_y = setup->stage.softpipe->scissor.miny; if (finish_y > setup->stage.softpipe->scissor.maxy) finish_y = setup->stage.softpipe->scissor.maxy; start_y -= sy; finish_y -= sy; } else { start_y = 0; finish_y = lines; } _mesa_printf("%s %d %d\n", __FUNCTION__, start_y, finish_y); for (y = start_y; y < finish_y; y++) { /* avoid accumulating adds as floats don't have the precision to * accurately iterate large triangle edges that way. luckily we * can just multiply these days. * * this is all drowned out by the attribute interpolation anyway. */ GLint left = (GLint)(eleft->sx + y * eleft->dxdy); GLint right = (GLint)(eright->sx + y * eright->dxdy); /* scissor x: */ if (setup->stage.softpipe->setup.scissor) { if (left < setup->stage.softpipe->scissor.minx) left = setup->stage.softpipe->scissor.minx; if (right > setup->stage.softpipe->scissor.maxx) right = setup->stage.softpipe->scissor.maxx; } if (left < right) { GLint _y = sy+y; if (block(_y) != setup->span.y) { flush_spans(setup); setup->span.y = block(_y); } setup->span.left[_y&1] = left; setup->span.right[_y&1] = right; setup->span.y_flags |= 1<<(_y&1); } } /* save the values so that emaj can be restarted: */ eleft->sx += lines * eleft->dxdy; eright->sx += lines * eright->dxdy; eleft->sy += lines; eright->sy += lines; } /** * Do setup for triangle rasterization, then render the triangle. */ static void setup_tri( struct prim_stage *stage, struct prim_header *prim ) { struct setup_stage *setup = setup_stage( stage ); _mesa_printf("%s\n", __FUNCTION__ ); setup_sort_vertices( setup, prim ); setup_tri_coefficients( setup ); setup_tri_edges( setup ); setup->span.y = 0; setup->span.y_flags = 0; setup->span.right[0] = 0; setup->span.right[1] = 0; // setup->span.z_mode = tri_z_mode( setup->ctx ); // init_constant_attribs( setup ); if (setup->oneoverarea < 0.0) { /* emaj on left: */ subtriangle( setup, &setup->emaj, &setup->ebot, setup->ebot.lines ); subtriangle( setup, &setup->emaj, &setup->etop, setup->etop.lines ); } else { /* emaj on right: */ subtriangle( setup, &setup->ebot, &setup->emaj, setup->ebot.lines ); subtriangle( setup, &setup->etop, &setup->emaj, setup->etop.lines ); } flush_spans( setup ); } /** * Compute a0, dadx and dady for a linearly interpolated coefficient, * for a line. */ static void line_linear_coeff(struct setup_stage *setup, GLuint slot, GLuint i) { const GLfloat dz = setup->vmax->data[slot][i] - setup->vmin->data[slot][i]; const GLfloat dadx = dz * setup->emaj.dx * setup->oneoverarea; const GLfloat dady = dz * setup->emaj.dy * setup->oneoverarea; setup->coef[slot].dadx[i] = dadx; setup->coef[slot].dady[i] = dady; setup->coef[slot].a0[i] = (setup->vmin->data[slot][i] - (dadx * (setup->vmin->data[0][0] - 0.5) + dady * (setup->vmin->data[0][1] - 0.5))); } /** * Compute a0, dadx and dady for a perspective-corrected interpolant, * for a line. */ static void line_persp_coeff(struct setup_stage *setup, GLuint slot, GLuint i) { /* XXX to do */ line_linear_coeff(setup, slot, i); /* XXX temporary */ } /** * Compute the setup->coef[] array dadx, dady, a0 values. * Must be called after setup->vmin,vmax are initialized. */ static INLINE void setup_line_coefficients(struct setup_stage *setup, struct prim_header *prim) { const enum interp_mode *interp = setup->stage.softpipe->interp; GLuint slot, j; /* use setup->vmin, vmax to point to vertices */ setup->vprovoke = prim->v[1]; setup->vmin = prim->v[0]; setup->vmax = prim->v[1]; setup->emaj.dx = setup->vmax->data[0][0] - setup->vmin->data[0][0]; setup->emaj.dy = setup->vmax->data[0][1] - setup->vmin->data[0][1]; /* NOTE: this is not really 1/area */ setup->oneoverarea = 1.0 / (setup->emaj.dx * setup->emaj.dx + setup->emaj.dy * setup->emaj.dy); /* z and w are done by linear interpolation: */ line_linear_coeff(setup, 0, 2); line_linear_coeff(setup, 0, 3); /* setup interpolation for all the remaining attributes: */ for (slot = 1; slot < setup->quad.nr_attrs; slot++) { switch (interp[slot]) { case INTERP_CONSTANT: for (j = 0; j < NUM_CHANNELS; j++) const_coeff(setup, slot, j); break; case INTERP_LINEAR: for (j = 0; j < NUM_CHANNELS; j++) line_linear_coeff(setup, slot, j); break; case INTERP_PERSPECTIVE: for (j = 0; j < NUM_CHANNELS; j++) line_persp_coeff(setup, slot, j); break; } } } /** * Plot a pixel in a line segment. */ static INLINE void plot(struct setup_stage *setup, GLint x, GLint y) { const GLint iy = y & 1; const GLint ix = x & 1; const GLint quadX = x - ix; const GLint quadY = y - iy; const GLint mask = (1 << ix) << (2 * iy); if (quadX != setup->quad.x0 || quadY != setup->quad.y0) { /* flush prev quad, start new quad */ if (setup->quad.x0 != -1) quad_shade(setup->stage.softpipe, &setup->quad); setup->quad.x0 = quadX; setup->quad.y0 = quadY; setup->quad.mask = 0x0; } setup->quad.mask |= mask; } /** * Do setup for line rasterization, then render the line. * XXX single-pixel width, no stipple, etc * XXX no scissoring yet. */ static void setup_line(struct prim_stage *stage, struct prim_header *prim) { const struct vertex_header *v0 = prim->v[0]; const struct vertex_header *v1 = prim->v[1]; struct setup_stage *setup = setup_stage( stage ); GLint x0 = (GLint) v0->data[0][0]; GLint x1 = (GLint) v1->data[0][0]; GLint y0 = (GLint) v0->data[0][1]; GLint y1 = (GLint) v1->data[0][1]; GLint dx = x1 - x0; GLint dy = y1 - y0; GLint xstep, ystep; if (dx == 0 && dy == 0) return; setup_line_coefficients(setup, prim); if (dx < 0) { dx = -dx; /* make positive */ xstep = -1; } else { xstep = 1; } if (dy < 0) { dy = -dy; /* make positive */ ystep = -1; } else { ystep = 1; } assert(dx >= 0); assert(dy >= 0); setup->quad.x0 = setup->quad.y0 = -1; setup->quad.mask = 0x0; if (dx > dy) { /*** X-major line ***/ GLint i; const GLint errorInc = dy + dy; GLint error = errorInc - dx; const GLint errorDec = error - dx; for (i = 0; i < dx; i++) { plot(setup, x0, y0); x0 += xstep; if (error < 0) { error += errorInc; } else { error += errorDec; y0 += ystep; } } } else { /*** Y-major line ***/ GLint i; const GLint errorInc = dx + dx; GLint error = errorInc - dy; const GLint errorDec = error - dy; for (i = 0; i < dy; i++) { plot(setup, x0, y0); y0 += ystep; if (error < 0) { error += errorInc; } else { error += errorDec; x0 += xstep; } } } /* draw final quad */ if (setup->quad.mask) { quad_shade(setup->stage.softpipe, &setup->quad); } } /** * Do setup for point rasterization, then render the point. * Round or square points... * XXX could optimize a lot for 1-pixel points. */ static void setup_point(struct prim_stage *stage, struct prim_header *prim) { struct setup_stage *setup = setup_stage( stage ); GLfloat halfSize = 7.3; /*XXX this is a vertex attrib */ GLfloat halfSizeSquared = halfSize * halfSize; const struct vertex_header *v0 = prim->v[0]; const GLfloat x = v0->data[FRAG_ATTRIB_WPOS][0]; const GLfloat y = v0->data[FRAG_ATTRIB_WPOS][1]; const GLint ixmin = block((GLint) (x - halfSize)); const GLint ixmax = block((GLint) (x + halfSize)); const GLint iymin = block((GLint) (y - halfSize)); const GLint iymax = block((GLint) (y + halfSize)); GLboolean round = GL_TRUE; GLint ix, iy; GLuint slot, j; /* For points, all interpolants are constant-valued. * However, for point sprites, we'll need to setup texcoords appropriately. * XXX: which coefficients are the texcoords??? * We may do point sprites as textured quads... * * KW: We don't know which coefficients are texcoords - ultimately * the choice of what interpolation mode to use for each attribute * should be determined by the fragment program, using * per-attribute declaration statements that include interpolation * mode as a parameter. So either the fragment program will have * to be adjusted for pointsprite vs normal point behaviour, or * otherwise a special interpolation mode will have to be defined * which matches the required behaviour for point sprites. But - * the latter is not a feature of normal hardware, and as such * probably should be ruled out on that basis. */ setup->vprovoke = prim->v[0]; const_coeff(setup, 0, 2); const_coeff(setup, 0, 3); for (slot = 1; slot < setup->quad.nr_attrs; slot++) { for (j = 0; j < NUM_CHANNELS; j++) const_coeff(setup, slot, j); } /* XXX need to clip against scissor bounds too */ for (iy = iymin; iy <= iymax; iy += 2) { for (ix = ixmin; ix <= ixmax; ix += 2) { if (round) { /* rounded points */ /* XXX for GL_SMOOTH, need to compute per-fragment coverage too */ GLfloat dx, dy; setup->quad.mask = 0x0; dx = (ix + 0.5) - x; dy = (iy + 0.5) - y; if (dx * dx + dy * dy <= halfSizeSquared) setup->quad.mask |= MASK_BOTTOM_LEFT; dx = (ix + 1.5) - x; dy = (iy + 0.5) - y; if (dx * dx + dy * dy <= halfSizeSquared) setup->quad.mask |= MASK_BOTTOM_RIGHT; dx = (ix + 0.5) - x; dy = (iy + 1.5) - y; if (dx * dx + dy * dy <= halfSizeSquared) setup->quad.mask |= MASK_TOP_LEFT; dx = (ix + 1.5) - x; dy = (iy + 1.5) - y; if (dx * dx + dy * dy <= halfSizeSquared) setup->quad.mask |= MASK_TOP_RIGHT; } else { /* square points */ setup->quad.mask = 0xf; if (ix + 0.5 < x - halfSize) setup->quad.mask &= (MASK_BOTTOM_RIGHT | MASK_TOP_RIGHT); if (ix + 1.5 > x + halfSize) setup->quad.mask &= (MASK_BOTTOM_LEFT | MASK_TOP_LEFT); if (iy + 0.5 < y - halfSize) setup->quad.mask &= (MASK_TOP_LEFT | MASK_TOP_RIGHT); if (iy + 1.5 > y + halfSize) setup->quad.mask &= (MASK_BOTTOM_LEFT | MASK_BOTTOM_RIGHT); } if (setup->quad.mask) { setup->quad.x0 = ix; setup->quad.y0 = iy; quad_shade( setup->stage.softpipe, &setup->quad ); } } } } static void setup_end( struct prim_stage *stage ) { } struct prim_stage *prim_setup( struct softpipe_context *softpipe ) { struct setup_stage *setup = CALLOC_STRUCT(setup_stage); setup->stage.softpipe = softpipe; setup->stage.begin = setup_begin; setup->stage.point = setup_point; setup->stage.line = setup_line; setup->stage.tri = setup_tri; setup->stage.end = setup_end; setup->quad.coef = setup->coef; return &setup->stage; }