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-rw-r--r--src/gallium/drivers/llvmpipe/lp_setup_tri.c618
1 files changed, 618 insertions, 0 deletions
diff --git a/src/gallium/drivers/llvmpipe/lp_setup_tri.c b/src/gallium/drivers/llvmpipe/lp_setup_tri.c
new file mode 100644
index 00000000000..9e59a6602cc
--- /dev/null
+++ b/src/gallium/drivers/llvmpipe/lp_setup_tri.c
@@ -0,0 +1,618 @@
+/**************************************************************************
+ *
+ * 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"
+
+#define NUM_CHANNELS 4
+
+
+/**
+ * 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;
+}
+
+
+/**
+ * Compute a0, dadx and dady for a linearly interpolated coefficient,
+ * for a triangle.
+ */
+static void linear_coef( struct lp_rast_triangle *tri,
+ float oneoverarea,
+ unsigned slot,
+ const float (*v1)[4],
+ const float (*v2)[4],
+ const float (*v3)[4],
+ unsigned vert_attr,
+ unsigned i)
+{
+ float a1 = v1[vert_attr][i];
+ float a2 = v2[vert_attr][i];
+ float a3 = v3[vert_attr][i];
+
+ float da12 = a1 - a2;
+ float da31 = a3 - a1;
+ float dadx = (da12 * tri->dy31 - tri->dy12 * da31) * oneoverarea;
+ float dady = (da31 * tri->dx12 - tri->dx31 * da12) * 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] = (a1 -
+ (dadx * (v1[0][0] - 0.5f) +
+ dady * (v1[0][1] - 0.5f)));
+}
+
+
+/**
+ * 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,
+ float oneoverarea,
+ unsigned slot,
+ const float (*v1)[4],
+ const float (*v2)[4],
+ const float (*v3)[4],
+ unsigned vert_attr,
+ unsigned i)
+{
+ /* premultiply by 1/w (v[0][3] is always 1/w):
+ */
+ float a1 = v1[vert_attr][i] * v1[0][3];
+ float a2 = v2[vert_attr][i] * v2[0][3];
+ float a3 = v3[vert_attr][i] * v3[0][3];
+ float da12 = a1 - a2;
+ float da31 = a3 - a1;
+ float dadx = (da12 * tri->dy31 - tri->dy12 * da31) * oneoverarea;
+ float dady = (da31 * tri->dx12 - tri->dx31 * da12) * oneoverarea;
+
+ tri->inputs.dadx[slot][i] = dadx;
+ tri->inputs.dady[slot][i] = dady;
+ tri->inputs.a0[slot][i] = (a1 -
+ (dadx * (v1[0][0] - 0.5f) +
+ dady * (v1[0][1] - 0.5f)));
+}
+
+
+/**
+ * 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,
+ float oneoverarea,
+ unsigned slot,
+ const float (*v1)[4],
+ const float (*v2)[4],
+ const float (*v3)[4])
+{
+ /*X*/
+ tri->inputs.a0[slot][0] = 0.0;
+ tri->inputs.dadx[slot][0] = 1.0;
+ tri->inputs.dady[slot][0] = 0.0;
+ /*Y*/
+ tri->inputs.a0[slot][1] = 0.0;
+ tri->inputs.dadx[slot][1] = 0.0;
+ tri->inputs.dady[slot][1] = 1.0;
+ /*Z*/
+ linear_coef(tri, oneoverarea, slot, v1, v2, v3, 0, 2);
+ /*W*/
+ linear_coef(tri, oneoverarea, slot, v1, v2, v3, 0, 3);
+}
+
+
+static void setup_facing_coef( struct lp_rast_triangle *tri,
+ unsigned slot,
+ boolean frontface )
+{
+ constant_coef( tri, slot, 1.0f - frontface, 0 );
+ constant_coef( tri, slot, 0.0f, 1 ); /* wasted */
+ constant_coef( tri, slot, 0.0f, 2 ); /* wasted */
+ constant_coef( tri, slot, 0.0f, 3 ); /* wasted */
+}
+
+
+/**
+ * Compute the tri->coef[] array dadx, dady, a0 values.
+ */
+static void setup_tri_coefficients( struct setup_context *setup,
+ struct lp_rast_triangle *tri,
+ float oneoverarea,
+ const float (*v1)[4],
+ const float (*v2)[4],
+ const float (*v3)[4],
+ boolean frontface)
+{
+ unsigned slot;
+
+ /* The internal position input is in slot zero:
+ */
+ setup_fragcoord_coef(tri, oneoverarea, 0, v1, v2, v3);
+
+ /* 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 i;
+
+ switch (setup->fs.input[slot].interp) {
+ case LP_INTERP_CONSTANT:
+ for (i = 0; i < NUM_CHANNELS; i++)
+ constant_coef(tri, slot+1, v3[vert_attr][i], i);
+ break;
+
+ case LP_INTERP_LINEAR:
+ for (i = 0; i < NUM_CHANNELS; i++)
+ linear_coef(tri, oneoverarea, slot+1, v1, v2, v3, vert_attr, i);
+ break;
+
+ case LP_INTERP_PERSPECTIVE:
+ for (i = 0; i < NUM_CHANNELS; i++)
+ perspective_coef(tri, oneoverarea, slot+1, v1, v2, v3, vert_attr, i);
+ break;
+
+ case LP_INTERP_POSITION:
+ /* XXX: fix me - duplicates the values in slot zero.
+ */
+ setup_fragcoord_coef(tri, oneoverarea, slot+1, v1, v2, v3);
+ break;
+
+ case LP_INTERP_FACING:
+ setup_facing_coef(tri, slot+1, frontface);
+ break;
+
+ default:
+ assert(0);
+ }
+ }
+}
+
+
+
+static INLINE int subpixel_snap( float a )
+{
+ return util_iround(FIXED_ONE * a - (FIXED_ONE / 2));
+}
+
+
+
+/**
+ * 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 *tri_size)
+{
+ unsigned input_array_sz = NUM_CHANNELS * (nr_inputs + 1) * sizeof(float);
+ struct lp_rast_triangle *tri;
+ unsigned bytes;
+ char *inputs;
+
+ assert(sizeof(*tri) % 16 == 0);
+
+ bytes = sizeof(*tri) + (3 * input_array_sz);
+
+ tri = lp_scene_alloc_aligned( scene, bytes, 16 );
+
+ inputs = (char *) (tri + 1);
+ 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;
+}
+
+
+
+/**
+ * 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 setup_context *setup,
+ const float (*v1)[4],
+ const float (*v2)[4],
+ const float (*v3)[4],
+ boolean frontfacing )
+{
+ /* x/y positions in fixed point */
+ const int x1 = subpixel_snap(v1[0][0]);
+ const int x2 = subpixel_snap(v2[0][0]);
+ const int x3 = subpixel_snap(v3[0][0]);
+ const int y1 = subpixel_snap(v1[0][1]);
+ const int y2 = subpixel_snap(v2[0][1]);
+ const int y3 = subpixel_snap(v3[0][1]);
+
+ struct lp_scene *scene = lp_setup_get_current_scene(setup);
+ struct lp_rast_triangle *tri;
+ int area;
+ float oneoverarea;
+ int minx, maxx, miny, maxy;
+ unsigned tri_bytes;
+
+ tri = alloc_triangle(scene, setup->fs.nr_inputs, &tri_bytes);
+
+ tri->dx12 = x1 - x2;
+ tri->dx23 = x2 - x3;
+ tri->dx31 = x3 - x1;
+
+ tri->dy12 = y1 - y2;
+ tri->dy23 = y2 - y3;
+ tri->dy31 = y3 - y1;
+
+ area = (tri->dx12 * tri->dy31 - tri->dx31 * tri->dy12);
+
+ 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) */
+ minx = (MIN3(x1, x2, x3) + (FIXED_ONE-1)) >> FIXED_ORDER;
+ maxx = (MAX3(x1, x2, x3) + (FIXED_ONE-1)) >> FIXED_ORDER;
+ miny = (MIN3(y1, y2, y3) + (FIXED_ONE-1)) >> FIXED_ORDER;
+ maxy = (MAX3(y1, y2, y3) + (FIXED_ONE-1)) >> 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);
+ }
+
+ if (miny == maxy ||
+ minx == maxx) {
+ lp_scene_putback_data( scene, tri_bytes );
+ LP_COUNT(nr_culled_tris);
+ return;
+ }
+
+ /*
+ */
+ oneoverarea = ((float)FIXED_ONE) / (float)area;
+
+ /* Setup parameter interpolants:
+ */
+ setup_tri_coefficients( setup, tri, oneoverarea, v1, v2, v3, frontfacing );
+
+ /* half-edge constants, will be interated over the whole render target.
+ */
+ tri->c1 = tri->dy12 * x1 - tri->dx12 * y1;
+ tri->c2 = tri->dy23 * x2 - tri->dx23 * y2;
+ tri->c3 = tri->dy31 * x3 - tri->dx31 * y3;
+
+ /* correct for top-left fill convention:
+ */
+ if (tri->dy12 < 0 || (tri->dy12 == 0 && tri->dx12 > 0)) tri->c1++;
+ if (tri->dy23 < 0 || (tri->dy23 == 0 && tri->dx23 > 0)) tri->c2++;
+ if (tri->dy31 < 0 || (tri->dy31 == 0 && tri->dx31 > 0)) tri->c3++;
+
+ tri->dy12 *= FIXED_ONE;
+ tri->dy23 *= FIXED_ONE;
+ tri->dy31 *= FIXED_ONE;
+
+ tri->dx12 *= FIXED_ONE;
+ tri->dx23 *= FIXED_ONE;
+ tri->dx31 *= 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.
+ */
+ tri->eo1 = 0;
+ if (tri->dy12 < 0) tri->eo1 -= tri->dy12;
+ if (tri->dx12 > 0) tri->eo1 += tri->dx12;
+
+ tri->eo2 = 0;
+ if (tri->dy23 < 0) tri->eo2 -= tri->dy23;
+ if (tri->dx23 > 0) tri->eo2 += tri->dx23;
+
+ tri->eo3 = 0;
+ if (tri->dy31 < 0) tri->eo3 -= tri->dy31;
+ if (tri->dx31 > 0) tri->eo3 += tri->dx31;
+
+ /* Calculate trivial accept offsets from the above.
+ */
+ tri->ei1 = tri->dx12 - tri->dy12 - tri->eo1;
+ tri->ei2 = tri->dx23 - tri->dy23 - tri->eo2;
+ tri->ei3 = tri->dx31 - tri->dy31 - tri->eo3;
+
+ /* Fill in the inputs.step[][] arrays.
+ * We've manually unrolled some loops here.
+ */
+ {
+ const int xstep1 = -tri->dy12;
+ const int xstep2 = -tri->dy23;
+ const int xstep3 = -tri->dy31;
+ const int ystep1 = tri->dx12;
+ const int ystep2 = tri->dx23;
+ const int ystep3 = tri->dx31;
+
+#define SETUP_STEP(i, x, y) \
+ do { \
+ tri->inputs.step[0][i] = x * xstep1 + y * ystep1; \
+ tri->inputs.step[1][i] = x * xstep2 + y * ystep2; \
+ tri->inputs.step[2][i] = x * xstep3 + y * ystep3; \
+ } while (0)
+
+ 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
+ }
+
+ /*
+ * All fields of 'tri' are now set. The remaining code here is
+ * concerned with binning.
+ */
+
+ /* Convert to tile coordinates:
+ */
+ minx = minx / TILE_SIZE;
+ miny = miny / TILE_SIZE;
+ maxx = maxx / TILE_SIZE;
+ maxy = maxy / TILE_SIZE;
+
+ /* Clamp maxx, maxy to framebuffer size
+ */
+ maxx = MIN2(maxx, scene->tiles_x - 1);
+ maxy = MIN2(maxy, scene->tiles_y - 1);
+
+ /* Determine which tile(s) intersect the triangle's bounding box
+ */
+ if (miny == maxy && minx == maxx)
+ {
+ /* Triangle is contained in a single tile:
+ */
+ lp_scene_bin_command( scene, minx, miny, lp_rast_triangle,
+ lp_rast_arg_triangle(tri) );
+ }
+ else
+ {
+ int c1 = (tri->c1 +
+ tri->dx12 * miny * TILE_SIZE -
+ tri->dy12 * minx * TILE_SIZE);
+ int c2 = (tri->c2 +
+ tri->dx23 * miny * TILE_SIZE -
+ tri->dy23 * minx * TILE_SIZE);
+ int c3 = (tri->c3 +
+ tri->dx31 * miny * TILE_SIZE -
+ tri->dy31 * minx * TILE_SIZE);
+
+ int ei1 = tri->ei1 << TILE_ORDER;
+ int ei2 = tri->ei2 << TILE_ORDER;
+ int ei3 = tri->ei3 << TILE_ORDER;
+
+ int eo1 = tri->eo1 << TILE_ORDER;
+ int eo2 = tri->eo2 << TILE_ORDER;
+ int eo3 = tri->eo3 << TILE_ORDER;
+
+ int xstep1 = -(tri->dy12 << TILE_ORDER);
+ int xstep2 = -(tri->dy23 << TILE_ORDER);
+ int xstep3 = -(tri->dy31 << TILE_ORDER);
+
+ int ystep1 = tri->dx12 << TILE_ORDER;
+ int ystep2 = tri->dx23 << TILE_ORDER;
+ int ystep3 = tri->dx31 << TILE_ORDER;
+ int x, y;
+
+
+ /* 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 = miny; y <= maxy; y++)
+ {
+ int cx1 = c1;
+ int cx2 = c2;
+ int cx3 = c3;
+ boolean in = FALSE; /* are we inside the triangle? */
+
+ for (x = minx; x <= maxx; x++)
+ {
+ if (cx1 + eo1 < 0 ||
+ cx2 + eo2 < 0 ||
+ cx3 + eo3 < 0)
+ {
+ /* do nothing */
+ LP_COUNT(nr_empty_64);
+ if (in)
+ break; /* exiting triangle, all done with this row */
+ }
+ else if (cx1 + ei1 > 0 &&
+ cx2 + ei2 > 0 &&
+ cx3 + ei3 > 0)
+ {
+ /* triangle covers the whole tile- shade whole tile */
+ LP_COUNT(nr_fully_covered_64);
+ in = TRUE;
+ if(setup->fs.current.opaque) {
+ lp_scene_bin_reset( scene, x, y );
+ lp_scene_bin_command( scene, x, y,
+ lp_rast_set_state,
+ lp_rast_arg_state(setup->fs.stored) );
+ }
+ lp_scene_bin_command( scene, x, y,
+ lp_rast_shade_tile,
+ lp_rast_arg_inputs(&tri->inputs) );
+ }
+ else
+ {
+ /* rasterizer/shade partial tile */
+ LP_COUNT(nr_partially_covered_64);
+ in = TRUE;
+ lp_scene_bin_command( scene, x, y,
+ lp_rast_triangle,
+ lp_rast_arg_triangle(tri) );
+ }
+
+ /* Iterate cx values across the region:
+ */
+ cx1 += xstep1;
+ cx2 += xstep2;
+ cx3 += xstep3;
+ }
+
+ /* Iterate c values down the region:
+ */
+ c1 += ystep1;
+ c2 += ystep2;
+ c3 += ystep3;
+ }
+ }
+}
+
+
+static void triangle_cw( struct 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 );
+}
+
+
+static void triangle_ccw( struct 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 );
+}
+
+
+static void triangle_both( struct 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 setup_context *setup,
+ const float (*v0)[4],
+ const float (*v1)[4],
+ const float (*v2)[4] )
+{
+}
+
+
+void
+lp_setup_choose_triangle( struct setup_context *setup )
+{
+ switch (setup->cullmode) {
+ case PIPE_WINDING_NONE:
+ setup->triangle = triangle_both;
+ break;
+ case PIPE_WINDING_CCW:
+ setup->triangle = triangle_cw;
+ break;
+ case PIPE_WINDING_CW:
+ setup->triangle = triangle_ccw;
+ break;
+ default:
+ setup->triangle = triangle_nop;
+ break;
+ }
+}
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