/**************************************************************************
*
* 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.
*
**************************************************************************/
/**
* \brief Primitive rasterization/rendering (points, lines, triangles)
*
* \author Keith Whitwell <keith@tungstengraphics.com>
* \author Brian Paul
*/
#include "sp_context.h"
#include "sp_quad.h"
#include "sp_quad_pipe.h"
#include "sp_setup.h"
#include "sp_state.h"
#include "draw/draw_context.h"
#include "draw/draw_vertex.h"
#include "pipe/p_shader_tokens.h"
#include "util/u_math.h"
#include "util/u_memory.h"
#define DEBUG_VERTS 0
#define DEBUG_FRAGS 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 */
};
/**
* Max number of quads (2x2 pixel blocks) to process per batch.
* This can't be arbitrarily increased since we depend on some 32-bit
* bitmasks (two bits per quad).
*/
#define MAX_QUADS 16
/**
* Triangle setup info.
* Also used for line drawing (taking some liberties).
*/
struct setup_context {
struct softpipe_context *softpipe;
/* 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 float (*vmax)[4];
const float (*vmid)[4];
const float (*vmin)[4];
const float (*vprovoke)[4];
struct edge ebot;
struct edge etop;
struct edge emaj;
float oneoverarea;
int facing;
float pixel_offset;
struct quad_header quad[MAX_QUADS];
struct quad_header *quad_ptrs[MAX_QUADS];
unsigned count;
struct tgsi_interp_coef coef[PIPE_MAX_SHADER_INPUTS];
struct tgsi_interp_coef posCoef; /* For Z, W */
struct {
int left[2]; /**< [0] = row0, [1] = row1 */
int right[2];
int y;
} span;
#if DEBUG_FRAGS
uint numFragsEmitted; /**< per primitive */
uint numFragsWritten; /**< per primitive */
#endif
unsigned cull_face; /* which faces cull */
unsigned nr_vertex_attrs;
};
/**
* Clip setup->quad against the scissor/surface bounds.
*/
static INLINE void
quad_clip(struct setup_context *setup, struct quad_header *quad)
{
const struct pipe_scissor_state *cliprect = &setup->softpipe->cliprect;
const int minx = (int) cliprect->minx;
const int maxx = (int) cliprect->maxx;
const int miny = (int) cliprect->miny;
const int maxy = (int) cliprect->maxy;
if (quad->input.x0 >= maxx ||
quad->input.y0 >= maxy ||
quad->input.x0 + 1 < minx ||
quad->input.y0 + 1 < miny) {
/* totally clipped */
quad->inout.mask = 0x0;
return;
}
if (quad->input.x0 < minx)
quad->inout.mask &= (MASK_BOTTOM_RIGHT | MASK_TOP_RIGHT);
if (quad->input.y0 < miny)
quad->inout.mask &= (MASK_BOTTOM_LEFT | MASK_BOTTOM_RIGHT);
if (quad->input.x0 == maxx - 1)
quad->inout.mask &= (MASK_BOTTOM_LEFT | MASK_TOP_LEFT);
if (quad->input.y0 == maxy - 1)
quad->inout.mask &= (MASK_TOP_LEFT | MASK_TOP_RIGHT);
}
/**
* Emit a quad (pass to next stage) with clipping.
*/
static INLINE void
clip_emit_quad(struct setup_context *setup, struct quad_header *quad)
{
quad_clip( setup, quad );
if (quad->inout.mask) {
struct softpipe_context *sp = setup->softpipe;
#if DEBUG_FRAGS
setup->numFragsEmitted += util_bitcount(quad->inout.mask);
#endif
sp->quad.first->run( sp->quad.first, &quad, 1 );
}
}
/**
* Given an X or Y coordinate, return the block/quad coordinate that it
* belongs to.
*/
static INLINE int
block(int x)
{
return x & ~(2-1);
}
static INLINE int
block_x(int x)
{
return x & ~(16-1);
}
/**
* Render a horizontal span of quads
*/
static void
flush_spans(struct setup_context *setup)
{
const int step = MAX_QUADS;
const int xleft0 = setup->span.left[0];
const int xleft1 = setup->span.left[1];
const int xright0 = setup->span.right[0];
const int xright1 = setup->span.right[1];
struct quad_stage *pipe = setup->softpipe->quad.first;
const int minleft = block_x(MIN2(xleft0, xleft1));
const int maxright = MAX2(xright0, xright1);
int x;
/* process quads in horizontal chunks of 16 */
for (x = minleft; x < maxright; x += step) {
unsigned skip_left0 = CLAMP(xleft0 - x, 0, step);
unsigned skip_left1 = CLAMP(xleft1 - x, 0, step);
unsigned skip_right0 = CLAMP(x + step - xright0, 0, step);
unsigned skip_right1 = CLAMP(x + step - xright1, 0, step);
unsigned lx = x;
unsigned q = 0;
unsigned skipmask_left0 = (1U << skip_left0) - 1U;
unsigned skipmask_left1 = (1U << skip_left1) - 1U;
/* These calculations fail when step == 32 and skip_right == 0.
*/
unsigned skipmask_right0 = ~0U << (unsigned)(step - skip_right0);
unsigned skipmask_right1 = ~0U << (unsigned)(step - skip_right1);
unsigned mask0 = ~skipmask_left0 & ~skipmask_right0;
unsigned mask1 = ~skipmask_left1 & ~skipmask_right1;
if (mask0 | mask1) {
do {
unsigned quadmask = (mask0 & 3) | ((mask1 & 3) << 2);
if (quadmask) {
setup->quad[q].input.x0 = lx;
setup->quad[q].input.y0 = setup->span.y;
setup->quad[q].input.facing = setup->facing;
setup->quad[q].inout.mask = quadmask;
setup->quad_ptrs[q] = &setup->quad[q];
q++;
#if DEBUG_FRAGS
setup->numFragsEmitted += util_bitcount(quadmask);
#endif
}
mask0 >>= 2;
mask1 >>= 2;
lx += 2;
} while (mask0 | mask1);
pipe->run( pipe, setup->quad_ptrs, q );
}
}
setup->span.y = 0;
setup->span.right[0] = 0;
setup->span.right[1] = 0;
setup->span.left[0] = 1000000; /* greater than right[0] */
setup->span.left[1] = 1000000; /* greater than right[1] */
}
#if DEBUG_VERTS
static void
print_vertex(const struct setup_context *setup,
const float (*v)[4])
{
int i;
debug_printf(" Vertex: (%p)\n", (void *) v);
for (i = 0; i < setup->nr_vertex_attrs; i++) {
debug_printf(" %d: %f %f %f %f\n", i,
v[i][0], v[i][1], v[i][2], v[i][3]);
if (util_is_inf_or_nan(v[i][0])) {
debug_printf(" NaN!\n");
}
}
}
#endif
/**
* Sort the vertices from top to bottom order, setting up the triangle
* edge fields (ebot, emaj, etop).
* \return FALSE if coords are inf/nan (cull the tri), TRUE otherwise
*/
static boolean
setup_sort_vertices(struct setup_context *setup,
float det,
const float (*v0)[4],
const float (*v1)[4],
const float (*v2)[4])
{
if (setup->softpipe->rasterizer->flatshade_first)
setup->vprovoke = v0;
else
setup->vprovoke = v2;
/* determine bottom to top order of vertices */
{
float y0 = v0[0][1];
float y1 = v1[0][1];
float y2 = v2[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[0][0] - setup->vmin[0][0];
setup->ebot.dy = setup->vmid[0][1] - setup->vmin[0][1];
setup->emaj.dx = setup->vmax[0][0] - setup->vmin[0][0];
setup->emaj.dy = setup->vmax[0][1] - setup->vmin[0][1];
setup->etop.dx = setup->vmax[0][0] - setup->vmid[0][0];
setup->etop.dy = setup->vmax[0][1] - setup->vmid[0][1];
/*
* Compute triangle's area. Use 1/area to compute partial
* derivatives of attributes later.
*
* The area will be the same as prim->det, but the sign may be
* different depending on how the vertices get sorted above.
*
* To determine whether the primitive is front or back facing we
* use the prim->det value because its sign is correct.
*/
{
const float area = (setup->emaj.dx * setup->ebot.dy -
setup->ebot.dx * setup->emaj.dy);
setup->oneoverarea = 1.0f / area;
/*
debug_printf("%s one-over-area %f area %f det %f\n",
__FUNCTION__, setup->oneoverarea, area, det );
*/
if (util_is_inf_or_nan(setup->oneoverarea))
return FALSE;
}
/* We need to know if this is a front or back-facing triangle for:
* - the GLSL gl_FrontFacing fragment attribute (bool)
* - two-sided stencil test
* 0 = front-facing, 1 = back-facing
*/
setup->facing =
((det < 0.0) ^
(setup->softpipe->rasterizer->front_ccw));
{
unsigned face = setup->facing == 0 ? PIPE_FACE_FRONT : PIPE_FACE_BACK;
if (face & setup->cull_face)
return FALSE;
}
/* Prepare pixel offset for rasterisation:
* - pixel center (0.5, 0.5) for GL, or
* - assume (0.0, 0.0) for other APIs.
*/
if (setup->softpipe->rasterizer->gl_rasterization_rules) {
setup->pixel_offset = 0.5f;
} else {
setup->pixel_offset = 0.0f;
}
return TRUE;
}
/* Apply cylindrical wrapping to v0, v1, v2 coordinates, if enabled.
* Input coordinates must be in [0, 1] range, otherwise results are undefined.
* Some combinations of coordinates produce invalid results,
* but this behaviour is acceptable.
*/
static void
tri_apply_cylindrical_wrap(float v0,
float v1,
float v2,
uint cylindrical_wrap,
float output[3])
{
if (cylindrical_wrap) {
float delta;
delta = v1 - v0;
if (delta > 0.5f) {
v0 += 1.0f;
}
else if (delta < -0.5f) {
v1 += 1.0f;
}
delta = v2 - v1;
if (delta > 0.5f) {
v1 += 1.0f;
}
else if (delta < -0.5f) {
v2 += 1.0f;
}
delta = v0 - v2;
if (delta > 0.5f) {
v2 += 1.0f;
}
else if (delta < -0.5f) {
v0 += 1.0f;
}
}
output[0] = v0;
output[1] = v1;
output[2] = v2;
}
/**
* Compute a0 for a constant-valued coefficient (GL_FLAT shading).
* The value value comes from vertex[slot][i].
* The result will be put into setup->coef[slot].a0[i].
* \param slot which attribute slot
* \param i which component of the slot (0..3)
*/
static void
const_coeff(struct setup_context *setup,
struct tgsi_interp_coef *coef,
uint vertSlot, uint i)
{
assert(i <= 3);
coef->dadx[i] = 0;
coef->dady[i] = 0;
/* need provoking vertex info!
*/
coef->a0[i] = setup->vprovoke[vertSlot][i];
}
/**
* Compute a0, dadx and dady for a linearly interpolated coefficient,
* for a triangle.
* v[0], v[1] and v[2] are vmin, vmid and vmax, respectively.
*/
static void
tri_linear_coeff(struct setup_context *setup,
struct tgsi_interp_coef *coef,
uint i,
const float v[3])
{
float botda = v[1] - v[0];
float majda = v[2] - v[0];
float a = setup->ebot.dy * majda - botda * setup->emaj.dy;
float b = setup->emaj.dx * botda - majda * setup->ebot.dx;
float dadx = a * setup->oneoverarea;
float dady = b * setup->oneoverarea;
assert(i <= 3);
coef->dadx[i] = dadx;
coef->dady[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 (pixel_offset, pixel_offset).
*
* 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.
*/
coef->a0[i] = (v[0] -
(dadx * (setup->vmin[0][0] - setup->pixel_offset) +
dady * (setup->vmin[0][1] - setup->pixel_offset)));
/*
debug_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.
* 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.
* v[0], v[1] and v[2] are vmin, vmid and vmax, respectively.
*/
static void
tri_persp_coeff(struct setup_context *setup,
struct tgsi_interp_coef *coef,
uint i,
const float v[3])
{
/* premultiply by 1/w (v[0][3] is always W):
*/
float mina = v[0] * setup->vmin[0][3];
float mida = v[1] * setup->vmid[0][3];
float maxa = v[2] * setup->vmax[0][3];
float botda = mida - mina;
float majda = maxa - mina;
float a = setup->ebot.dy * majda - botda * setup->emaj.dy;
float b = setup->emaj.dx * botda - majda * setup->ebot.dx;
float dadx = a * setup->oneoverarea;
float dady = b * setup->oneoverarea;
/*
debug_printf("tri persp %d,%d: %f %f %f\n", vertSlot, i,
setup->vmin[vertSlot][i],
setup->vmid[vertSlot][i],
setup->vmax[vertSlot][i]
);
*/
assert(i <= 3);
coef->dadx[i] = dadx;
coef->dady[i] = dady;
coef->a0[i] = (mina -
(dadx * (setup->vmin[0][0] - setup->pixel_offset) +
dady * (setup->vmin[0][1] - setup->pixel_offset)));
}
/**
* Special coefficient setup for gl_FragCoord.
* X and Y are trivial, though Y may have to be inverted for OpenGL.
* Z and W are copied from posCoef 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_coeff(struct setup_context *setup, uint slot)
{
const struct tgsi_shader_info *fsInfo = &setup->softpipe->fs_variant->info;
/*X*/
setup->coef[slot].a0[0] = fsInfo->pixel_center_integer ? 0.0 : 0.5;
setup->coef[slot].dadx[0] = 1.0;
setup->coef[slot].dady[0] = 0.0;
/*Y*/
setup->coef[slot].a0[1] =
(fsInfo->origin_lower_left ? setup->softpipe->framebuffer.height-1 : 0)
+ (fsInfo->pixel_center_integer ? 0.0 : 0.5);
setup->coef[slot].dadx[1] = 0.0;
setup->coef[slot].dady[1] = fsInfo->origin_lower_left ? -1.0 : 1.0;
/*Z*/
setup->coef[slot].a0[2] = setup->posCoef.a0[2];
setup->coef[slot].dadx[2] = setup->posCoef.dadx[2];
setup->coef[slot].dady[2] = setup->posCoef.dady[2];
/*W*/
setup->coef[slot].a0[3] = setup->posCoef.a0[3];
setup->coef[slot].dadx[3] = setup->posCoef.dadx[3];
setup->coef[slot].dady[3] = setup->posCoef.dady[3];
}
/**
* 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_context *setup)
{
struct softpipe_context *softpipe = setup->softpipe;
const struct tgsi_shader_info *fsInfo = &setup->softpipe->fs_variant->info;
const struct vertex_info *vinfo = softpipe_get_vertex_info(softpipe);
uint fragSlot;
float v[3];
/* z and w are done by linear interpolation:
*/
v[0] = setup->vmin[0][2];
v[1] = setup->vmid[0][2];
v[2] = setup->vmax[0][2];
tri_linear_coeff(setup, &setup->posCoef, 2, v);
v[0] = setup->vmin[0][3];
v[1] = setup->vmid[0][3];
v[2] = setup->vmax[0][3];
tri_linear_coeff(setup, &setup->posCoef, 3, v);
/* setup interpolation for all the remaining attributes:
*/
for (fragSlot = 0; fragSlot < fsInfo->num_inputs; fragSlot++) {
const uint vertSlot = vinfo->attrib[fragSlot].src_index;
uint j;
switch (vinfo->attrib[fragSlot].interp_mode) {
case INTERP_CONSTANT:
for (j = 0; j < TGSI_NUM_CHANNELS; j++)
const_coeff(setup, &setup->coef[fragSlot], vertSlot, j);
break;
case INTERP_LINEAR:
for (j = 0; j < TGSI_NUM_CHANNELS; j++) {
tri_apply_cylindrical_wrap(setup->vmin[vertSlot][j],
setup->vmid[vertSlot][j],
setup->vmax[vertSlot][j],
fsInfo->input_cylindrical_wrap[fragSlot] & (1 << j),
v);
tri_linear_coeff(setup, &setup->coef[fragSlot], j, v);
}
break;
case INTERP_PERSPECTIVE:
for (j = 0; j < TGSI_NUM_CHANNELS; j++) {
tri_apply_cylindrical_wrap(setup->vmin[vertSlot][j],
setup->vmid[vertSlot][j],
setup->vmax[vertSlot][j],
fsInfo->input_cylindrical_wrap[fragSlot] & (1 << j),
v);
tri_persp_coeff(setup, &setup->coef[fragSlot], j, v);
}
break;
case INTERP_POS:
setup_fragcoord_coeff(setup, fragSlot);
break;
default:
assert(0);
}
if (fsInfo->input_semantic_name[fragSlot] == TGSI_SEMANTIC_FACE) {
/* convert 0 to 1.0 and 1 to -1.0 */
setup->coef[fragSlot].a0[0] = setup->facing * -2.0f + 1.0f;
setup->coef[fragSlot].dadx[0] = 0.0;
setup->coef[fragSlot].dady[0] = 0.0;
}
}
}
static void
setup_tri_edges(struct setup_context *setup)
{
float vmin_x = setup->vmin[0][0] + setup->pixel_offset;
float vmid_x = setup->vmid[0][0] + setup->pixel_offset;
float vmin_y = setup->vmin[0][1] - setup->pixel_offset;
float vmid_y = setup->vmid[0][1] - setup->pixel_offset;
float vmax_y = setup->vmax[0][1] - setup->pixel_offset;
setup->emaj.sy = ceilf(vmin_y);
setup->emaj.lines = (int) ceilf(vmax_y - setup->emaj.sy);
setup->emaj.dxdy = setup->emaj.dy ? setup->emaj.dx / setup->emaj.dy : .0f;
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.dy ? setup->etop.dx / setup->etop.dy : .0f;
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.dy ? setup->ebot.dx / setup->ebot.dy : .0f;
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 setup_context *setup,
struct edge *eleft,
struct edge *eright,
int lines)
{
const struct pipe_scissor_state *cliprect = &setup->softpipe->cliprect;
const int minx = (int) cliprect->minx;
const int maxx = (int) cliprect->maxx;
const int miny = (int) cliprect->miny;
const int maxy = (int) cliprect->maxy;
int y, start_y, finish_y;
int sy = (int)eleft->sy;
assert((int)eleft->sy == (int) eright->sy);
assert(lines >= 0);
/* clip top/bottom */
start_y = sy;
if (start_y < miny)
start_y = miny;
finish_y = sy + lines;
if (finish_y > maxy)
finish_y = maxy;
start_y -= sy;
finish_y -= sy;
/*
debug_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);
setup->span.y = block(_y);
}
setup->span.left[_y&1] = left;
setup->span.right[_y&1] = right;
}
}
/* 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;
}
/**
* Recalculate prim's determinant. This is needed as we don't have
* get this information through the vbuf_render interface & we must
* calculate it here.
*/
static float
calc_det(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 */
return ex * fy - ey * fx;
}
/**
* Do setup for triangle rasterization, then render the triangle.
*/
void
sp_setup_tri(struct setup_context *setup,
const float (*v0)[4],
const float (*v1)[4],
const float (*v2)[4])
{
float det;
#if DEBUG_VERTS
debug_printf("Setup triangle:\n");
print_vertex(setup, v0);
print_vertex(setup, v1);
print_vertex(setup, v2);
#endif
if (setup->softpipe->no_rast || setup->softpipe->rasterizer->rasterizer_discard)
return;
det = calc_det(v0, v1, v2);
/*
debug_printf("%s\n", __FUNCTION__ );
*/
#if DEBUG_FRAGS
setup->numFragsEmitted = 0;
setup->numFragsWritten = 0;
#endif
if (!setup_sort_vertices( setup, det, v0, v1, v2 ))
return;
setup_tri_coefficients( setup );
setup_tri_edges( setup );
assert(setup->softpipe->reduced_prim == PIPE_PRIM_TRIANGLES);
setup->span.y = 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 );
#if DEBUG_FRAGS
printf("Tri: %u frags emitted, %u written\n",
setup->numFragsEmitted,
setup->numFragsWritten);
#endif
}
/* Apply cylindrical wrapping to v0, v1 coordinates, if enabled.
* Input coordinates must be in [0, 1] range, otherwise results are undefined.
*/
static void
line_apply_cylindrical_wrap(float v0,
float v1,
uint cylindrical_wrap,
float output[2])
{
if (cylindrical_wrap) {
float delta;
delta = v1 - v0;
if (delta > 0.5f) {
v0 += 1.0f;
}
else if (delta < -0.5f) {
v1 += 1.0f;
}
}
output[0] = v0;
output[1] = v1;
}
/**
* Compute a0, dadx and dady for a linearly interpolated coefficient,
* for a line.
* v[0] and v[1] are vmin and vmax, respectively.
*/
static void
line_linear_coeff(const struct setup_context *setup,
struct tgsi_interp_coef *coef,
uint i,
const float v[2])
{
const float da = v[1] - v[0];
const float dadx = da * setup->emaj.dx * setup->oneoverarea;
const float dady = da * setup->emaj.dy * setup->oneoverarea;
coef->dadx[i] = dadx;
coef->dady[i] = dady;
coef->a0[i] = (v[0] -
(dadx * (setup->vmin[0][0] - setup->pixel_offset) +
dady * (setup->vmin[0][1] - setup->pixel_offset)));
}
/**
* Compute a0, dadx and dady for a perspective-corrected interpolant,
* for a line.
* v[0] and v[1] are vmin and vmax, respectively.
*/
static void
line_persp_coeff(const struct setup_context *setup,
struct tgsi_interp_coef *coef,
uint i,
const float v[2])
{
const float a0 = v[0] * setup->vmin[0][3];
const float a1 = v[1] * setup->vmax[0][3];
const float da = a1 - a0;
const float dadx = da * setup->emaj.dx * setup->oneoverarea;
const float dady = da * setup->emaj.dy * setup->oneoverarea;
coef->dadx[i] = dadx;
coef->dady[i] = dady;
coef->a0[i] = (a0 -
(dadx * (setup->vmin[0][0] - setup->pixel_offset) +
dady * (setup->vmin[0][1] - setup->pixel_offset)));
}
/**
* Compute the setup->coef[] array dadx, dady, a0 values.
* Must be called after setup->vmin,vmax are initialized.
*/
static boolean
setup_line_coefficients(struct setup_context *setup,
const float (*v0)[4],
const float (*v1)[4])
{
struct softpipe_context *softpipe = setup->softpipe;
const struct tgsi_shader_info *fsInfo = &setup->softpipe->fs_variant->info;
const struct vertex_info *vinfo = softpipe_get_vertex_info(softpipe);
uint fragSlot;
float area;
float v[2];
/* use setup->vmin, vmax to point to vertices */
if (softpipe->rasterizer->flatshade_first)
setup->vprovoke = v0;
else
setup->vprovoke = v1;
setup->vmin = v0;
setup->vmax = v1;
setup->emaj.dx = setup->vmax[0][0] - setup->vmin[0][0];
setup->emaj.dy = setup->vmax[0][1] - setup->vmin[0][1];
/* NOTE: this is not really area but something proportional to it */
area = setup->emaj.dx * setup->emaj.dx + setup->emaj.dy * setup->emaj.dy;
if (area == 0.0f || util_is_inf_or_nan(area))
return FALSE;
setup->oneoverarea = 1.0f / area;
/* z and w are done by linear interpolation:
*/
v[0] = setup->vmin[0][2];
v[1] = setup->vmax[0][2];
line_linear_coeff(setup, &setup->posCoef, 2, v);
v[0] = setup->vmin[0][3];
v[1] = setup->vmax[0][3];
line_linear_coeff(setup, &setup->posCoef, 3, v);
/* setup interpolation for all the remaining attributes:
*/
for (fragSlot = 0; fragSlot < fsInfo->num_inputs; fragSlot++) {
const uint vertSlot = vinfo->attrib[fragSlot].src_index;
uint j;
switch (vinfo->attrib[fragSlot].interp_mode) {
case INTERP_CONSTANT:
for (j = 0; j < TGSI_NUM_CHANNELS; j++)
const_coeff(setup, &setup->coef[fragSlot], vertSlot, j);
break;
case INTERP_LINEAR:
for (j = 0; j < TGSI_NUM_CHANNELS; j++) {
line_apply_cylindrical_wrap(setup->vmin[vertSlot][j],
setup->vmax[vertSlot][j],
fsInfo->input_cylindrical_wrap[fragSlot] & (1 << j),
v);
line_linear_coeff(setup, &setup->coef[fragSlot], j, v);
}
break;
case INTERP_PERSPECTIVE:
for (j = 0; j < TGSI_NUM_CHANNELS; j++) {
line_apply_cylindrical_wrap(setup->vmin[vertSlot][j],
setup->vmax[vertSlot][j],
fsInfo->input_cylindrical_wrap[fragSlot] & (1 << j),
v);
line_persp_coeff(setup, &setup->coef[fragSlot], j, v);
}
break;
case INTERP_POS:
setup_fragcoord_coeff(setup, fragSlot);
break;
default:
assert(0);
}
if (fsInfo->input_semantic_name[fragSlot] == TGSI_SEMANTIC_FACE) {
/* convert 0 to 1.0 and 1 to -1.0 */
setup->coef[fragSlot].a0[0] = setup->facing * -2.0f + 1.0f;
setup->coef[fragSlot].dadx[0] = 0.0;
setup->coef[fragSlot].dady[0] = 0.0;
}
}
return TRUE;
}
/**
* Plot a pixel in a line segment.
*/
static INLINE void
plot(struct setup_context *setup, int x, int y)
{
const int iy = y & 1;
const int ix = x & 1;
const int quadX = x - ix;
const int quadY = y - iy;
const int mask = (1 << ix) << (2 * iy);
if (quadX != setup->quad[0].input.x0 ||
quadY != setup->quad[0].input.y0)
{
/* flush prev quad, start new quad */
if (setup->quad[0].input.x0 != -1)
clip_emit_quad( setup, &setup->quad[0] );
setup->quad[0].input.x0 = quadX;
setup->quad[0].input.y0 = quadY;
setup->quad[0].inout.mask = 0x0;
}
setup->quad[0].inout.mask |= mask;
}
/**
* Do setup for line rasterization, then render the line.
* Single-pixel width, no stipple, etc. We rely on the 'draw' module
* to handle stippling and wide lines.
*/
void
sp_setup_line(struct setup_context *setup,
const float (*v0)[4],
const float (*v1)[4])
{
int x0 = (int) v0[0][0];
int x1 = (int) v1[0][0];
int y0 = (int) v0[0][1];
int y1 = (int) v1[0][1];
int dx = x1 - x0;
int dy = y1 - y0;
int xstep, ystep;
#if DEBUG_VERTS
debug_printf("Setup line:\n");
print_vertex(setup, v0);
print_vertex(setup, v1);
#endif
if (setup->softpipe->no_rast || setup->softpipe->rasterizer->rasterizer_discard)
return;
if (dx == 0 && dy == 0)
return;
if (!setup_line_coefficients(setup, v0, v1))
return;
assert(v0[0][0] < 1.0e9);
assert(v0[0][1] < 1.0e9);
assert(v1[0][0] < 1.0e9);
assert(v1[0][1] < 1.0e9);
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);
assert(setup->softpipe->reduced_prim == PIPE_PRIM_LINES);
setup->quad[0].input.x0 = setup->quad[0].input.y0 = -1;
setup->quad[0].inout.mask = 0x0;
/* XXX temporary: set coverage to 1.0 so the line appears
* if AA mode happens to be enabled.
*/
setup->quad[0].input.coverage[0] =
setup->quad[0].input.coverage[1] =
setup->quad[0].input.coverage[2] =
setup->quad[0].input.coverage[3] = 1.0;
if (dx > dy) {
/*** X-major line ***/
int i;
const int errorInc = dy + dy;
int error = errorInc - dx;
const int 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 ***/
int i;
const int errorInc = dx + dx;
int error = errorInc - dy;
const int 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[0].inout.mask) {
clip_emit_quad( setup, &setup->quad[0] );
}
}
static void
point_persp_coeff(const struct setup_context *setup,
const float (*vert)[4],
struct tgsi_interp_coef *coef,
uint vertSlot, uint i)
{
assert(i <= 3);
coef->dadx[i] = 0.0F;
coef->dady[i] = 0.0F;
coef->a0[i] = vert[vertSlot][i] * vert[0][3];
}
/**
* Do setup for point rasterization, then render the point.
* Round or square points...
* XXX could optimize a lot for 1-pixel points.
*/
void
sp_setup_point(struct setup_context *setup,
const float (*v0)[4])
{
struct softpipe_context *softpipe = setup->softpipe;
const struct tgsi_shader_info *fsInfo = &setup->softpipe->fs_variant->info;
const int sizeAttr = setup->softpipe->psize_slot;
const float size
= sizeAttr > 0 ? v0[sizeAttr][0]
: setup->softpipe->rasterizer->point_size;
const float halfSize = 0.5F * size;
const boolean round = (boolean) setup->softpipe->rasterizer->point_smooth;
const float x = v0[0][0]; /* Note: data[0] is always position */
const float y = v0[0][1];
const struct vertex_info *vinfo = softpipe_get_vertex_info(softpipe);
uint fragSlot;
#if DEBUG_VERTS
debug_printf("Setup point:\n");
print_vertex(setup, v0);
#endif
if (setup->softpipe->no_rast || setup->softpipe->rasterizer->rasterizer_discard)
return;
assert(setup->softpipe->reduced_prim == PIPE_PRIM_POINTS);
/* 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 = v0;
/* setup Z, W */
const_coeff(setup, &setup->posCoef, 0, 2);
const_coeff(setup, &setup->posCoef, 0, 3);
for (fragSlot = 0; fragSlot < fsInfo->num_inputs; fragSlot++) {
const uint vertSlot = vinfo->attrib[fragSlot].src_index;
uint j;
switch (vinfo->attrib[fragSlot].interp_mode) {
case INTERP_CONSTANT:
/* fall-through */
case INTERP_LINEAR:
for (j = 0; j < TGSI_NUM_CHANNELS; j++)
const_coeff(setup, &setup->coef[fragSlot], vertSlot, j);
break;
case INTERP_PERSPECTIVE:
for (j = 0; j < TGSI_NUM_CHANNELS; j++)
point_persp_coeff(setup, setup->vprovoke,
&setup->coef[fragSlot], vertSlot, j);
break;
case INTERP_POS:
setup_fragcoord_coeff(setup, fragSlot);
break;
default:
assert(0);
}
if (fsInfo->input_semantic_name[fragSlot] == TGSI_SEMANTIC_FACE) {
/* convert 0 to 1.0 and 1 to -1.0 */
setup->coef[fragSlot].a0[0] = setup->facing * -2.0f + 1.0f;
setup->coef[fragSlot].dadx[0] = 0.0;
setup->coef[fragSlot].dady[0] = 0.0;
}
}
if (halfSize <= 0.5 && !round) {
/* special case for 1-pixel points */
const int ix = ((int) x) & 1;
const int iy = ((int) y) & 1;
setup->quad[0].input.x0 = (int) x - ix;
setup->quad[0].input.y0 = (int) y - iy;
setup->quad[0].inout.mask = (1 << ix) << (2 * iy);
clip_emit_quad( setup, &setup->quad[0] );
}
else {
if (round) {
/* rounded points */
const int ixmin = block((int) (x - halfSize));
const int ixmax = block((int) (x + halfSize));
const int iymin = block((int) (y - halfSize));
const int iymax = block((int) (y + halfSize));
const float rmin = halfSize - 0.7071F; /* 0.7071 = sqrt(2)/2 */
const float rmax = halfSize + 0.7071F;
const float rmin2 = MAX2(0.0F, rmin * rmin);
const float rmax2 = rmax * rmax;
const float cscale = 1.0F / (rmax2 - rmin2);
int ix, iy;
for (iy = iymin; iy <= iymax; iy += 2) {
for (ix = ixmin; ix <= ixmax; ix += 2) {
float dx, dy, dist2, cover;
setup->quad[0].inout.mask = 0x0;
dx = (ix + 0.5f) - x;
dy = (iy + 0.5f) - y;
dist2 = dx * dx + dy * dy;
if (dist2 <= rmax2) {
cover = 1.0F - (dist2 - rmin2) * cscale;
setup->quad[0].input.coverage[QUAD_TOP_LEFT] = MIN2(cover, 1.0f);
setup->quad[0].inout.mask |= MASK_TOP_LEFT;
}
dx = (ix + 1.5f) - x;
dy = (iy + 0.5f) - y;
dist2 = dx * dx + dy * dy;
if (dist2 <= rmax2) {
cover = 1.0F - (dist2 - rmin2) * cscale;
setup->quad[0].input.coverage[QUAD_TOP_RIGHT] = MIN2(cover, 1.0f);
setup->quad[0].inout.mask |= MASK_TOP_RIGHT;
}
dx = (ix + 0.5f) - x;
dy = (iy + 1.5f) - y;
dist2 = dx * dx + dy * dy;
if (dist2 <= rmax2) {
cover = 1.0F - (dist2 - rmin2) * cscale;
setup->quad[0].input.coverage[QUAD_BOTTOM_LEFT] = MIN2(cover, 1.0f);
setup->quad[0].inout.mask |= MASK_BOTTOM_LEFT;
}
dx = (ix + 1.5f) - x;
dy = (iy + 1.5f) - y;
dist2 = dx * dx + dy * dy;
if (dist2 <= rmax2) {
cover = 1.0F - (dist2 - rmin2) * cscale;
setup->quad[0].input.coverage[QUAD_BOTTOM_RIGHT] = MIN2(cover, 1.0f);
setup->quad[0].inout.mask |= MASK_BOTTOM_RIGHT;
}
if (setup->quad[0].inout.mask) {
setup->quad[0].input.x0 = ix;
setup->quad[0].input.y0 = iy;
clip_emit_quad( setup, &setup->quad[0] );
}
}
}
}
else {
/* square points */
const int xmin = (int) (x + 0.75 - halfSize);
const int ymin = (int) (y + 0.25 - halfSize);
const int xmax = xmin + (int) size;
const int ymax = ymin + (int) size;
/* XXX could apply scissor to xmin,ymin,xmax,ymax now */
const int ixmin = block(xmin);
const int ixmax = block(xmax - 1);
const int iymin = block(ymin);
const int iymax = block(ymax - 1);
int ix, iy;
/*
debug_printf("(%f, %f) -> X:%d..%d Y:%d..%d\n", x, y, xmin, xmax,ymin,ymax);
*/
for (iy = iymin; iy <= iymax; iy += 2) {
uint rowMask = 0xf;
if (iy < ymin) {
/* above the top edge */
rowMask &= (MASK_BOTTOM_LEFT | MASK_BOTTOM_RIGHT);
}
if (iy + 1 >= ymax) {
/* below the bottom edge */
rowMask &= (MASK_TOP_LEFT | MASK_TOP_RIGHT);
}
for (ix = ixmin; ix <= ixmax; ix += 2) {
uint mask = rowMask;
if (ix < xmin) {
/* fragment is past left edge of point, turn off left bits */
mask &= (MASK_BOTTOM_RIGHT | MASK_TOP_RIGHT);
}
if (ix + 1 >= xmax) {
/* past the right edge */
mask &= (MASK_BOTTOM_LEFT | MASK_TOP_LEFT);
}
setup->quad[0].inout.mask = mask;
setup->quad[0].input.x0 = ix;
setup->quad[0].input.y0 = iy;
clip_emit_quad( setup, &setup->quad[0] );
}
}
}
}
}
/**
* Called by vbuf code just before we start buffering primitives.
*/
void
sp_setup_prepare(struct setup_context *setup)
{
struct softpipe_context *sp = setup->softpipe;
if (sp->dirty) {
softpipe_update_derived(sp, sp->reduced_api_prim);
}
/* Note: nr_attrs is only used for debugging (vertex printing) */
setup->nr_vertex_attrs = draw_num_shader_outputs(sp->draw);
sp->quad.first->begin( sp->quad.first );
if (sp->reduced_api_prim == PIPE_PRIM_TRIANGLES &&
sp->rasterizer->fill_front == PIPE_POLYGON_MODE_FILL &&
sp->rasterizer->fill_back == PIPE_POLYGON_MODE_FILL) {
/* we'll do culling */
setup->cull_face = sp->rasterizer->cull_face;
}
else {
/* 'draw' will do culling */
setup->cull_face = PIPE_FACE_NONE;
}
}
void
sp_setup_destroy_context(struct setup_context *setup)
{
FREE( setup );
}
/**
* Create a new primitive setup/render stage.
*/
struct setup_context *
sp_setup_create_context(struct softpipe_context *softpipe)
{
struct setup_context *setup = CALLOC_STRUCT(setup_context);
unsigned i;
setup->softpipe = softpipe;
for (i = 0; i < MAX_QUADS; i++) {
setup->quad[i].coef = setup->coef;
setup->quad[i].posCoef = &setup->posCoef;
}
setup->span.left[0] = 1000000; /* greater than right[0] */
setup->span.left[1] = 1000000; /* greater than right[1] */
return setup;
}