From 63b1f23b3eb6fceaff7c2ceed925ef57f63f9fa2 Mon Sep 17 00:00:00 2001 From: Brian Paul Date: Tue, 1 Dec 2009 15:43:01 -0700 Subject: llvmpipe: comments, reformatting and assertions in tri rast code --- src/gallium/drivers/llvmpipe/lp_rast_tri.c | 117 +++++++++++++++++------------ 1 file changed, 70 insertions(+), 47 deletions(-) (limited to 'src/gallium/drivers/llvmpipe') diff --git a/src/gallium/drivers/llvmpipe/lp_rast_tri.c b/src/gallium/drivers/llvmpipe/lp_rast_tri.c index 174e6ab19b..428870bb04 100644 --- a/src/gallium/drivers/llvmpipe/lp_rast_tri.c +++ b/src/gallium/drivers/llvmpipe/lp_rast_tri.c @@ -37,12 +37,16 @@ #define BLOCKSIZE 4 -/* Render a 4x4 unmasked block: +/** + * Add a 4x4 block of pixels to the block list. + * All pixels are known to be inside the triangle's bounds. */ -static void block_full_4( struct lp_rasterizer *rast, - int x, int y ) +static void +block_full_4( struct lp_rasterizer *rast, int x, int y ) { int i = rast->nr_blocks; + assert(x % 4 == 0); + assert(y % 4 == 0); rast->blocks[i].x = x; rast->blocks[i].y = y; rast->blocks[i].mask = ~0; @@ -50,20 +54,26 @@ static void block_full_4( struct lp_rasterizer *rast, } -static void block_full_16( struct lp_rasterizer *rast, - int x, int y ) +/** + * Add a 16x16 block of pixels to the block list. + * All pixels are known to be inside the triangle's bounds. + */ +static void +block_full_16( struct lp_rasterizer *rast, int x, int y ) { unsigned ix, iy; - - for (iy = 0; iy < 16; iy+=4) - for (ix = 0; ix < 16; ix+=4) + assert(x % 16 == 0); + assert(y % 16 == 0); + for (iy = 0; iy < 16; iy += 4) + for (ix = 0; ix < 16; ix += 4) block_full_4(rast, x + ix, y + iy); } - -/* Evaluate each pixel in a block, generate a mask and possibly render - * the quad: +/** + * Evaluate each pixel in a 4x4 block to determine if it lies within + * the triangle's bounds. + * Generate a mask of in/out flags and add the block to the blocks list. */ static void do_block_4( struct lp_rasterizer *rast, @@ -76,13 +86,15 @@ do_block_4( struct lp_rasterizer *rast, int i; unsigned mask = 0; + assert(x % 4 == 0); + assert(y % 4 == 0); + for (i = 0; i < 16; i++) mask |= (~(((c1 + tri->step[0][i]) | (c2 + tri->step[1][i]) | (c3 + tri->step[2][i])) >> 31)) & (1 << i); - /* As we do trivial reject already, masks should rarely be all - * zero: + /* As we do trivial reject already, masks should rarely be all zero: */ if (mask) { int i = rast->nr_blocks; @@ -93,15 +105,20 @@ do_block_4( struct lp_rasterizer *rast, } } + +/** + * Evaluate a 16x16 block of pixels to determine which 4x4 subblocks are in/out + * of the triangle's bounds. + */ static void do_block_16( struct lp_rasterizer *rast, - const struct lp_rast_triangle *tri, - int x, int y, - int c1, - int c2, - int c3 ) + const struct lp_rast_triangle *tri, + int x, int y, + int c1, + int c2, + int c3 ) { - int ix,iy,i = 0; + int ix, iy, i = 0; int ei1 = tri->ei1 << 2; int ei2 = tri->ei2 << 2; @@ -111,44 +128,48 @@ do_block_16( struct lp_rasterizer *rast, int eo2 = tri->eo2 << 2; int eo3 = tri->eo3 << 2; - for (iy = 0; iy < 16; iy+=4) - { - for (ix = 0; ix < 16; ix+=4, i++) - { + assert(x % 16 == 0); + assert(y % 16 == 0); + + for (iy = 0; iy < 16; iy+=4) { + for (ix = 0; ix < 16; ix+=4, i++) { int cx1 = c1 + (tri->step[0][i] << 2); int cx2 = c2 + (tri->step[1][i] << 2); int cx3 = c3 + (tri->step[2][i] << 2); if (cx1 + eo1 < 0 || cx2 + eo2 < 0 || - cx3 + eo3 < 0) - { + cx3 + eo3 < 0) { + /* the block is completely outside the triangle - nop */ } else if (cx1 + ei1 > 0 && cx2 + ei2 > 0 && - cx3 + ei3 > 0) - { - block_full_4(rast, x+ix, y+iy); /* trivial accept */ + cx3 + ei3 > 0) { + /* the block is completely inside the triangle */ + block_full_4(rast, x+ix, y+iy); } - else - { + else { + /* the block is partially in/out of the triangle */ do_block_4(rast, tri, x+ix, y+iy, cx1, cx2, cx3); } } } } -/* Scan the tile in chunks and figure out which pixels to rasterize - * for this triangle: + +/** + * Scan the tile in chunks and figure out which pixels to rasterize + * for this triangle. */ -void lp_rast_triangle( struct lp_rasterizer *rast, - const union lp_rast_cmd_arg arg ) +void +lp_rast_triangle( struct lp_rasterizer *rast, + const union lp_rast_cmd_arg arg ) { const struct lp_rast_triangle *tri = arg.triangle; int x = rast->x; int y = rast->y; - int ix,iy,i = 0; + int ix, iy, i = 0; int c1 = tri->c1 + tri->dx12 * y - tri->dy12 * x; int c2 = tri->c2 + tri->dx23 * y - tri->dy23 * x; @@ -166,36 +187,38 @@ void lp_rast_triangle( struct lp_rasterizer *rast, rast->nr_blocks = 0; - for (iy = 0; iy < 64; iy+=16) - { - for (ix = 0; ix < 64; ix+=16, i++) - { + /* Walk over the tile to build a list of 4x4 pixel blocks which will + * be filled/shaded. We do this at two granularities: 16x16 blocks + * and then 4x4 blocks. + */ + for (iy = 0; iy < TILE_SIZE; iy += 16) { + for (ix = 0; ix < TILE_SIZE; ix += 16, i++) { int cx1 = c1 + (tri->step[0][i] << 4); int cx2 = c2 + (tri->step[1][i] << 4); int cx3 = c3 + (tri->step[2][i] << 4); if (cx1 + eo1 < 0 || cx2 + eo2 < 0 || - cx3 + eo3 < 0) - { + cx3 + eo3 < 0) { + /* the block is completely outside the triangle - nop */ } else if (cx1 + ei1 > 0 && cx2 + ei2 > 0 && - cx3 + ei3 > 0) - { - block_full_16(rast, x+ix, y+iy); /* trivial accept */ + cx3 + ei3 > 0) { + /* the block is completely inside the triangle */ + block_full_16(rast, x+ix, y+iy); } - else - { + else { + /* the block is partially in/out of the triangle */ do_block_16(rast, tri, x+ix, y+iy, cx1, cx2, cx3); } } } + /* Shade the 4x4 pixel blocks */ for (i = 0; i < rast->nr_blocks; i++) lp_rast_shade_quads(rast, &tri->inputs, rast->blocks[i].x, rast->blocks[i].y, rast->blocks[i].mask); } - -- cgit v1.2.3