diff options
Diffstat (limited to 'src/gallium/drivers/cell/spu/spu_tri.c')
-rw-r--r-- | src/gallium/drivers/cell/spu/spu_tri.c | 810 |
1 files changed, 810 insertions, 0 deletions
diff --git a/src/gallium/drivers/cell/spu/spu_tri.c b/src/gallium/drivers/cell/spu/spu_tri.c new file mode 100644 index 00000000000..22e51a86ae5 --- /dev/null +++ b/src/gallium/drivers/cell/spu/spu_tri.c @@ -0,0 +1,810 @@ +/************************************************************************** + * + * 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. + * + **************************************************************************/ + +/** + * Triangle rendering within a tile. + */ + +#include <transpose_matrix4x4.h> +#include "pipe/p_compiler.h" +#include "pipe/p_format.h" +#include "util/u_math.h" +#include "spu_colorpack.h" +#include "spu_main.h" +#include "spu_texture.h" +#include "spu_tile.h" +#include "spu_tri.h" + + +/** Masks are uint[4] vectors with each element being 0 or 0xffffffff */ +typedef vector unsigned int mask_t; + + + +/** + * Simplified types taken from other parts of Gallium + */ +struct vertex_header { + vector float data[1]; +}; + + + +/* XXX fix this */ +#undef CEILF +#define CEILF(X) ((float) (int) ((X) + 0.99999)) + + +#define QUAD_TOP_LEFT 0 +#define QUAD_TOP_RIGHT 1 +#define QUAD_BOTTOM_LEFT 2 +#define QUAD_BOTTOM_RIGHT 3 +#define MASK_TOP_LEFT (1 << QUAD_TOP_LEFT) +#define MASK_TOP_RIGHT (1 << QUAD_TOP_RIGHT) +#define MASK_BOTTOM_LEFT (1 << QUAD_BOTTOM_LEFT) +#define MASK_BOTTOM_RIGHT (1 << QUAD_BOTTOM_RIGHT) +#define MASK_ALL 0xf + + +#define DEBUG_VERTS 0 + +/** + * Triangle edge info + */ +struct edge { + float dx; /**< X(v1) - X(v0), used only during setup */ + float dy; /**< Y(v1) - Y(v0), used only during setup */ + float dxdy; /**< dx/dy */ + float sx, sy; /**< first sample point coord */ + int lines; /**< number of lines on this edge */ +}; + + +struct interp_coef +{ + vector float a0; + vector float dadx; + vector float dady; +}; + + +/** + * Triangle setup info (derived from draw_stage). + * Also used for line drawing (taking some liberties). + */ +struct setup_stage { + + /* 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; + + float oneOverArea; /* XXX maybe make into vector? */ + + uint facing; + + uint tx, ty; /**< position of current tile (x, y) */ + + int cliprect_minx, cliprect_maxx, cliprect_miny, cliprect_maxy; + + struct interp_coef coef[PIPE_MAX_SHADER_INPUTS]; + + struct { + int left[2]; /**< [0] = row0, [1] = row1 */ + int right[2]; + int y; + unsigned y_flags; + unsigned mask; /**< mask of MASK_BOTTOM/TOP_LEFT/RIGHT bits */ + } span; +}; + + +static struct setup_stage setup; + + +/** + * Evaluate attribute coefficients (plane equations) to compute + * attribute values for the four fragments in a quad. + * Eg: four colors will be computed (in AoS format). + */ +static INLINE void +eval_coeff(uint slot, float x, float y, vector float w, vector float result[4]) +{ + switch (spu.vertex_info.attrib[slot].interp_mode) { + case INTERP_CONSTANT: + result[QUAD_TOP_LEFT] = + result[QUAD_TOP_RIGHT] = + result[QUAD_BOTTOM_LEFT] = + result[QUAD_BOTTOM_RIGHT] = setup.coef[slot].a0; + break; + case INTERP_LINEAR: + { + vector float dadx = setup.coef[slot].dadx; + vector float dady = setup.coef[slot].dady; + vector float topLeft = + spu_add(setup.coef[slot].a0, + spu_add(spu_mul(spu_splats(x), dadx), + spu_mul(spu_splats(y), dady))); + + result[QUAD_TOP_LEFT] = topLeft; + result[QUAD_TOP_RIGHT] = spu_add(topLeft, dadx); + result[QUAD_BOTTOM_LEFT] = spu_add(topLeft, dady); + result[QUAD_BOTTOM_RIGHT] = spu_add(spu_add(topLeft, dadx), dady); + } + break; + case INTERP_PERSPECTIVE: + { + vector float dadx = setup.coef[slot].dadx; + vector float dady = setup.coef[slot].dady; + vector float topLeft = + spu_add(setup.coef[slot].a0, + spu_add(spu_mul(spu_splats(x), dadx), + spu_mul(spu_splats(y), dady))); + + vector float wInv = spu_re(w); /* 1.0 / w */ + + result[QUAD_TOP_LEFT] = spu_mul(topLeft, wInv); + result[QUAD_TOP_RIGHT] = spu_mul(spu_add(topLeft, dadx), wInv); + result[QUAD_BOTTOM_LEFT] = spu_mul(spu_add(topLeft, dady), wInv); + result[QUAD_BOTTOM_RIGHT] = spu_mul(spu_add(spu_add(topLeft, dadx), dady), wInv); + } + break; + case INTERP_POS: + case INTERP_NONE: + break; + default: + ASSERT(0); + } +} + + +/** + * As above, but return 4 vectors in SOA format. + * XXX this will all be re-written someday. + */ +static INLINE void +eval_coeff_soa(uint slot, float x, float y, vector float w, vector float result[4]) +{ + eval_coeff(slot, x, y, w, result); + _transpose_matrix4x4(result, result); +} + + +/** Evalute coefficients to get Z for four pixels in a quad */ +static INLINE vector float +eval_z(float x, float y) +{ + const uint slot = 0; + const float dzdx = spu_extract(setup.coef[slot].dadx, 2); + const float dzdy = spu_extract(setup.coef[slot].dady, 2); + const float topLeft = spu_extract(setup.coef[slot].a0, 2) + x * dzdx + y * dzdy; + const vector float topLeftv = spu_splats(topLeft); + const vector float derivs = (vector float) { 0.0, dzdx, dzdy, dzdx + dzdy }; + return spu_add(topLeftv, derivs); +} + + +/** Evalute coefficients to get W for four pixels in a quad */ +static INLINE vector float +eval_w(float x, float y) +{ + const uint slot = 0; + const float dwdx = spu_extract(setup.coef[slot].dadx, 3); + const float dwdy = spu_extract(setup.coef[slot].dady, 3); + const float topLeft = spu_extract(setup.coef[slot].a0, 3) + x * dwdx + y * dwdy; + const vector float topLeftv = spu_splats(topLeft); + const vector float derivs = (vector float) { 0.0, dwdx, dwdy, dwdx + dwdy }; + return spu_add(topLeftv, derivs); +} + + +/** + * Emit a quad (pass to next stage). No clipping is done. + * Note: about 1/5 to 1/7 of the time, mask is zero and this function + * should be skipped. But adding the test for that slows things down + * overall. + */ +static INLINE void +emit_quad( int x, int y, mask_t mask) +{ + /* If any bits in mask are set... */ + if (spu_extract(spu_orx(mask), 0)) { + const int ix = x - setup.cliprect_minx; + const int iy = y - setup.cliprect_miny; + + spu.cur_ctile_status = TILE_STATUS_DIRTY; + spu.cur_ztile_status = TILE_STATUS_DIRTY; + + { + /* + * Run fragment shader, execute per-fragment ops, update fb/tile. + */ + vector float inputs[4*4], outputs[2*4]; + vector float fragZ = eval_z((float) x, (float) y); + vector float fragW = eval_w((float) x, (float) y); + vector unsigned int kill_mask; + + /* setup inputs */ +#if 0 + eval_coeff_soa(1, (float) x, (float) y, fragW, inputs); +#else + uint i; + for (i = 0; i < spu.vertex_info.num_attribs; i++) { + eval_coeff_soa(i+1, (float) x, (float) y, fragW, inputs + i * 4); + } +#endif + ASSERT(spu.fragment_program); + ASSERT(spu.fragment_ops); + + /* Execute the current fragment program */ + kill_mask = spu.fragment_program(inputs, outputs, spu.constants); + + mask = spu_andc(mask, kill_mask); + + /* Execute per-fragment/quad operations, including: + * alpha test, z test, stencil test, blend and framebuffer writing. + * Note that there are two different fragment operations functions + * that can be called, one for front-facing fragments, and one + * for back-facing fragments. (Often the two are the same; + * but in some cases, like two-sided stenciling, they can be + * very different.) So choose the correct function depending + * on the calculated facing. + */ + spu.fragment_ops[setup.facing](ix, iy, &spu.ctile, &spu.ztile, + fragZ, + outputs[0*4+0], + outputs[0*4+1], + outputs[0*4+2], + outputs[0*4+3], + mask); + } + } +} + + +/** + * Given an X or Y coordinate, return the block/quad coordinate that it + * belongs to. + */ +static INLINE int +block(int x) +{ + return x & ~1; +} + + +/** + * Compute mask which indicates which pixels in the 2x2 quad are actually inside + * the triangle's bounds. + * The mask is a uint4 vector and each element will be 0 or 0xffffffff. + */ +static INLINE mask_t +calculate_mask(int x) +{ + /* This is a little tricky. + * Use & instead of && to avoid branches. + * Use negation to convert true/false to ~0/0 values. + */ + mask_t mask; + mask = spu_insert(-((x >= setup.span.left[0]) & (x < setup.span.right[0])), mask, 0); + mask = spu_insert(-((x+1 >= setup.span.left[0]) & (x+1 < setup.span.right[0])), mask, 1); + mask = spu_insert(-((x >= setup.span.left[1]) & (x < setup.span.right[1])), mask, 2); + mask = spu_insert(-((x+1 >= setup.span.left[1]) & (x+1 < setup.span.right[1])), mask, 3); + return mask; +} + + +/** + * Render a horizontal span of quads + */ +static void +flush_spans(void) +{ + int minleft, maxright; + int x; + + switch (setup.span.y_flags) { + case 0x3: + /* both odd and even lines written (both quad rows) */ + minleft = MIN2(setup.span.left[0], setup.span.left[1]); + maxright = MAX2(setup.span.right[0], setup.span.right[1]); + break; + + case 0x1: + /* only even line written (quad top row) */ + minleft = setup.span.left[0]; + maxright = setup.span.right[0]; + break; + + case 0x2: + /* only odd line written (quad bottom row) */ + minleft = setup.span.left[1]; + maxright = setup.span.right[1]; + break; + + default: + return; + } + + /* OK, we're very likely to need the tile data now. + * clear or finish waiting if needed. + */ + if (spu.cur_ctile_status == TILE_STATUS_GETTING) { + /* wait for mfc_get() to complete */ + //printf("SPU: %u: waiting for ctile\n", spu.init.id); + wait_on_mask(1 << TAG_READ_TILE_COLOR); + spu.cur_ctile_status = TILE_STATUS_CLEAN; + } + else if (spu.cur_ctile_status == TILE_STATUS_CLEAR) { + //printf("SPU %u: clearing C tile %u, %u\n", spu.init.id, setup.tx, setup.ty); + clear_c_tile(&spu.ctile); + spu.cur_ctile_status = TILE_STATUS_DIRTY; + } + ASSERT(spu.cur_ctile_status != TILE_STATUS_DEFINED); + + if (spu.read_depth_stencil) { + if (spu.cur_ztile_status == TILE_STATUS_GETTING) { + /* wait for mfc_get() to complete */ + //printf("SPU: %u: waiting for ztile\n", spu.init.id); + wait_on_mask(1 << TAG_READ_TILE_Z); + spu.cur_ztile_status = TILE_STATUS_CLEAN; + } + else if (spu.cur_ztile_status == TILE_STATUS_CLEAR) { + //printf("SPU %u: clearing Z tile %u, %u\n", spu.init.id, setup.tx, setup.ty); + clear_z_tile(&spu.ztile); + spu.cur_ztile_status = TILE_STATUS_DIRTY; + } + ASSERT(spu.cur_ztile_status != TILE_STATUS_DEFINED); + } + + /* XXX this loop could be moved into the above switch cases and + * calculate_mask() could be simplified a bit... + */ + for (x = block(minleft); x <= block(maxright); x += 2) { + emit_quad( x, setup.span.y, calculate_mask( x )); + } + + setup.span.y = 0; + setup.span.y_flags = 0; + setup.span.right[0] = 0; + setup.span.right[1] = 0; +} + + +#if DEBUG_VERTS +static void +print_vertex(const struct vertex_header *v) +{ + uint i; + fprintf(stderr, " Vertex: (%p)\n", v); + for (i = 0; i < spu.vertex_info.num_attribs; i++) { + fprintf(stderr, " %d: %f %f %f %f\n", i, + spu_extract(v->data[i], 0), + spu_extract(v->data[i], 1), + spu_extract(v->data[i], 2), + spu_extract(v->data[i], 3)); + } +} +#endif + + +/** + * Sort vertices from top to bottom. + * Compute area and determine front vs. back facing. + * Do coarse clip test against tile bounds + * \return FALSE if tri is totally outside tile, TRUE otherwise + */ +static boolean +setup_sort_vertices(const struct vertex_header *v0, + const struct vertex_header *v1, + const struct vertex_header *v2) +{ + float area, sign; + +#if DEBUG_VERTS + if (spu.init.id==0) { + fprintf(stderr, "SPU %u: Triangle:\n", spu.init.id); + print_vertex(v0); + print_vertex(v1); + print_vertex(v2); + } +#endif + + /* determine bottom to top order of vertices */ + { + float y0 = spu_extract(v0->data[0], 1); + float y1 = spu_extract(v1->data[0], 1); + float y2 = spu_extract(v2->data[0], 1); + if (y0 <= y1) { + if (y1 <= y2) { + /* y0<=y1<=y2 */ + setup.vmin = v0; + setup.vmid = v1; + setup.vmax = v2; + sign = -1.0f; + } + else if (y2 <= y0) { + /* y2<=y0<=y1 */ + setup.vmin = v2; + setup.vmid = v0; + setup.vmax = v1; + sign = -1.0f; + } + else { + /* y0<=y2<=y1 */ + setup.vmin = v0; + setup.vmid = v2; + setup.vmax = v1; + sign = 1.0f; + } + } + else { + if (y0 <= y2) { + /* y1<=y0<=y2 */ + setup.vmin = v1; + setup.vmid = v0; + setup.vmax = v2; + sign = 1.0f; + } + else if (y2 <= y1) { + /* y2<=y1<=y0 */ + setup.vmin = v2; + setup.vmid = v1; + setup.vmax = v0; + sign = 1.0f; + } + else { + /* y1<=y2<=y0 */ + setup.vmin = v1; + setup.vmid = v2; + setup.vmax = v0; + sign = -1.0f; + } + } + } + + /* Check if triangle is completely outside the tile bounds */ + if (spu_extract(setup.vmin->data[0], 1) > setup.cliprect_maxy) + return FALSE; + if (spu_extract(setup.vmax->data[0], 1) < setup.cliprect_miny) + return FALSE; + if (spu_extract(setup.vmin->data[0], 0) < setup.cliprect_minx && + spu_extract(setup.vmid->data[0], 0) < setup.cliprect_minx && + spu_extract(setup.vmax->data[0], 0) < setup.cliprect_minx) + return FALSE; + if (spu_extract(setup.vmin->data[0], 0) > setup.cliprect_maxx && + spu_extract(setup.vmid->data[0], 0) > setup.cliprect_maxx && + spu_extract(setup.vmax->data[0], 0) > setup.cliprect_maxx) + return FALSE; + + setup.ebot.dx = spu_extract(setup.vmid->data[0], 0) - spu_extract(setup.vmin->data[0], 0); + setup.ebot.dy = spu_extract(setup.vmid->data[0], 1) - spu_extract(setup.vmin->data[0], 1); + setup.emaj.dx = spu_extract(setup.vmax->data[0], 0) - spu_extract(setup.vmin->data[0], 0); + setup.emaj.dy = spu_extract(setup.vmax->data[0], 1) - spu_extract(setup.vmin->data[0], 1); + setup.etop.dx = spu_extract(setup.vmax->data[0], 0) - spu_extract(setup.vmid->data[0], 0); + setup.etop.dy = spu_extract(setup.vmax->data[0], 1) - spu_extract(setup.vmid->data[0], 1); + + /* + * Compute triangle's area. Use 1/area to compute partial + * derivatives of attributes later. + */ + area = setup.emaj.dx * setup.ebot.dy - setup.ebot.dx * setup.emaj.dy; + + setup.oneOverArea = 1.0f / area; + + /* The product of area * sign indicates front/back orientation (0/1). + * Just in case someone gets the bright idea of switching the front + * and back constants without noticing that we're assuming their + * values in this operation, also assert that the values are + * what we think they are. + */ + ASSERT(CELL_FACING_FRONT == 0); + ASSERT(CELL_FACING_BACK == 1); + setup.facing = (area * sign > 0.0f) + ^ (spu.rasterizer.front_winding == PIPE_WINDING_CW); + + setup.vprovoke = v2; + + return TRUE; +} + + +/** + * Compute a0 for a constant-valued coefficient (GL_FLAT shading). + * The value value comes from vertex->data[slot]. + * The result will be put into setup.coef[slot].a0. + * \param slot which attribute slot + */ +static INLINE void +const_coeff4(uint slot) +{ + setup.coef[slot].dadx = (vector float) {0.0, 0.0, 0.0, 0.0}; + setup.coef[slot].dady = (vector float) {0.0, 0.0, 0.0, 0.0}; + setup.coef[slot].a0 = setup.vprovoke->data[slot]; +} + + +/** + * As above, but interp setup all four vector components. + */ +static INLINE void +tri_linear_coeff4(uint slot) +{ + const vector float vmin_d = setup.vmin->data[slot]; + const vector float vmid_d = setup.vmid->data[slot]; + const vector float vmax_d = setup.vmax->data[slot]; + const vector float xxxx = spu_splats(spu_extract(setup.vmin->data[0], 0) - 0.5f); + const vector float yyyy = spu_splats(spu_extract(setup.vmin->data[0], 1) - 0.5f); + + vector float botda = vmid_d - vmin_d; + vector float majda = vmax_d - vmin_d; + + vector float a = spu_sub(spu_mul(spu_splats(setup.ebot.dy), majda), + spu_mul(botda, spu_splats(setup.emaj.dy))); + vector float b = spu_sub(spu_mul(spu_splats(setup.emaj.dx), botda), + spu_mul(majda, spu_splats(setup.ebot.dx))); + + setup.coef[slot].dadx = spu_mul(a, spu_splats(setup.oneOverArea)); + setup.coef[slot].dady = spu_mul(b, spu_splats(setup.oneOverArea)); + + vector float tempx = spu_mul(setup.coef[slot].dadx, xxxx); + vector float tempy = spu_mul(setup.coef[slot].dady, yyyy); + + setup.coef[slot].a0 = spu_sub(vmin_d, spu_add(tempx, tempy)); +} + + +/** + * 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 +tri_persp_coeff4(uint slot) +{ + const vector float xxxx = spu_splats(spu_extract(setup.vmin->data[0], 0) - 0.5f); + const vector float yyyy = spu_splats(spu_extract(setup.vmin->data[0], 1) - 0.5f); + + const vector float vmin_w = spu_splats(spu_extract(setup.vmin->data[0], 3)); + const vector float vmid_w = spu_splats(spu_extract(setup.vmid->data[0], 3)); + const vector float vmax_w = spu_splats(spu_extract(setup.vmax->data[0], 3)); + + vector float vmin_d = setup.vmin->data[slot]; + vector float vmid_d = setup.vmid->data[slot]; + vector float vmax_d = setup.vmax->data[slot]; + + vmin_d = spu_mul(vmin_d, vmin_w); + vmid_d = spu_mul(vmid_d, vmid_w); + vmax_d = spu_mul(vmax_d, vmax_w); + + vector float botda = vmid_d - vmin_d; + vector float majda = vmax_d - vmin_d; + + vector float a = spu_sub(spu_mul(spu_splats(setup.ebot.dy), majda), + spu_mul(botda, spu_splats(setup.emaj.dy))); + vector float b = spu_sub(spu_mul(spu_splats(setup.emaj.dx), botda), + spu_mul(majda, spu_splats(setup.ebot.dx))); + + setup.coef[slot].dadx = spu_mul(a, spu_splats(setup.oneOverArea)); + setup.coef[slot].dady = spu_mul(b, spu_splats(setup.oneOverArea)); + + vector float tempx = spu_mul(setup.coef[slot].dadx, xxxx); + vector float tempy = spu_mul(setup.coef[slot].dady, yyyy); + + setup.coef[slot].a0 = spu_sub(vmin_d, spu_add(tempx, tempy)); +} + + + +/** + * 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(void) +{ + uint i; + + for (i = 0; i < spu.vertex_info.num_attribs; i++) { + switch (spu.vertex_info.attrib[i].interp_mode) { + case INTERP_NONE: + break; + case INTERP_CONSTANT: + const_coeff4(i); + break; + case INTERP_POS: + /* fall-through */ + case INTERP_LINEAR: + tri_linear_coeff4(i); + break; + case INTERP_PERSPECTIVE: + tri_persp_coeff4(i); + break; + default: + ASSERT(0); + } + } +} + + +static void +setup_tri_edges(void) +{ + float vmin_x = spu_extract(setup.vmin->data[0], 0) + 0.5f; + float vmid_x = spu_extract(setup.vmid->data[0], 0) + 0.5f; + + float vmin_y = spu_extract(setup.vmin->data[0], 1) - 0.5f; + float vmid_y = spu_extract(setup.vmid->data[0], 1) - 0.5f; + float vmax_y = spu_extract(setup.vmax->data[0], 1) - 0.5f; + + setup.emaj.sy = CEILF(vmin_y); + setup.emaj.lines = (int) 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 = (int) 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 = (int) 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/cliprect is applied here too. + */ +static void +subtriangle(struct edge *eleft, struct edge *eright, unsigned lines) +{ + const int minx = setup.cliprect_minx; + const int maxx = setup.cliprect_maxx; + const int miny = setup.cliprect_miny; + const int maxy = setup.cliprect_maxy; + int y, start_y, finish_y; + int sy = (int)eleft->sy; + + ASSERT((int)eleft->sy == (int) eright->sy); + + /* clip top/bottom */ + start_y = sy; + finish_y = sy + lines; + + if (start_y < miny) + start_y = miny; + + if (finish_y > maxy) + finish_y = maxy; + + start_y -= sy; + finish_y -= sy; + + /* + _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. + */ + int left = (int)(eleft->sx + y * eleft->dxdy); + int right = (int)(eright->sx + y * eright->dxdy); + + /* clip left/right */ + if (left < minx) + left = minx; + if (right > maxx) + right = maxx; + + if (left < right) { + int _y = sy + y; + if (block(_y) != setup.span.y) { + flush_spans(); + 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; +} + + +/** + * Draw triangle into tile at (tx, ty) (tile coords) + * The tile data should have already been fetched. + */ +boolean +tri_draw(const float *v0, const float *v1, const float *v2, + uint tx, uint ty) +{ + setup.tx = tx; + setup.ty = ty; + + /* set clipping bounds to tile bounds */ + setup.cliprect_minx = tx * TILE_SIZE; + setup.cliprect_miny = ty * TILE_SIZE; + setup.cliprect_maxx = (tx + 1) * TILE_SIZE; + setup.cliprect_maxy = (ty + 1) * TILE_SIZE; + + if (!setup_sort_vertices((struct vertex_header *) v0, + (struct vertex_header *) v1, + (struct vertex_header *) v2)) { + return FALSE; /* totally clipped */ + } + + setup_tri_coefficients(); + setup_tri_edges(); + + setup.span.y = 0; + setup.span.y_flags = 0; + setup.span.right[0] = 0; + setup.span.right[1] = 0; + + if (setup.oneOverArea < 0.0) { + /* emaj on left */ + subtriangle( &setup.emaj, &setup.ebot, setup.ebot.lines ); + subtriangle( &setup.emaj, &setup.etop, setup.etop.lines ); + } + else { + /* emaj on right */ + subtriangle( &setup.ebot, &setup.emaj, setup.ebot.lines ); + subtriangle( &setup.etop, &setup.emaj, setup.etop.lines ); + } + + flush_spans(); + + return TRUE; +} |