/**************************************************************************
*
* 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 lines
*/
#include "util/u_math.h"
#include "util/u_memory.h"
#include "lp_perf.h"
#include "lp_setup_context.h"
#include "lp_rast.h"
#include "lp_state_fs.h"
#include "lp_state_setup.h"
#define NUM_CHANNELS 4
struct lp_line_info {
float dx;
float dy;
float oneoverarea;
const float (*v1)[4];
const float (*v2)[4];
float (*a0)[4];
float (*dadx)[4];
float (*dady)[4];
};
/**
* Compute a0 for a constant-valued coefficient (GL_FLAT shading).
*/
static void constant_coef( struct lp_setup_context *setup,
struct lp_line_info *info,
unsigned slot,
const float value,
unsigned i )
{
info->a0[slot][i] = value;
info->dadx[slot][i] = 0.0f;
info->dady[slot][i] = 0.0f;
}
/**
* Compute a0, dadx and dady for a linearly interpolated coefficient,
* for a triangle.
*/
static void linear_coef( struct lp_setup_context *setup,
struct lp_line_info *info,
unsigned slot,
unsigned vert_attr,
unsigned i)
{
float a1 = info->v1[vert_attr][i];
float a2 = info->v2[vert_attr][i];
float da21 = a1 - a2;
float dadx = da21 * info->dx * info->oneoverarea;
float dady = da21 * info->dy * info->oneoverarea;
info->dadx[slot][i] = dadx;
info->dady[slot][i] = dady;
info->a0[slot][i] = (a1 -
(dadx * (info->v1[0][0] - setup->pixel_offset) +
dady * (info->v1[0][1] - setup->pixel_offset)));
}
/**
* 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_setup_context *setup,
struct lp_line_info *info,
unsigned slot,
unsigned vert_attr,
unsigned i)
{
/* premultiply by 1/w (v[0][3] is always 1/w):
*/
float a1 = info->v1[vert_attr][i] * info->v1[0][3];
float a2 = info->v2[vert_attr][i] * info->v2[0][3];
float da21 = a1 - a2;
float dadx = da21 * info->dx * info->oneoverarea;
float dady = da21 * info->dy * info->oneoverarea;
info->dadx[slot][i] = dadx;
info->dady[slot][i] = dady;
info->a0[slot][i] = (a1 -
(dadx * (info->v1[0][0] - setup->pixel_offset) +
dady * (info->v1[0][1] - setup->pixel_offset)));
}
static void
setup_fragcoord_coef( struct lp_setup_context *setup,
struct lp_line_info *info,
unsigned slot,
unsigned usage_mask)
{
/*X*/
if (usage_mask & TGSI_WRITEMASK_X) {
info->a0[slot][0] = 0.0;
info->dadx[slot][0] = 1.0;
info->dady[slot][0] = 0.0;
}
/*Y*/
if (usage_mask & TGSI_WRITEMASK_Y) {
info->a0[slot][1] = 0.0;
info->dadx[slot][1] = 0.0;
info->dady[slot][1] = 1.0;
}
/*Z*/
if (usage_mask & TGSI_WRITEMASK_Z) {
linear_coef(setup, info, slot, 0, 2);
}
/*W*/
if (usage_mask & TGSI_WRITEMASK_W) {
linear_coef(setup, info, slot, 0, 3);
}
}
/**
* Compute the tri->coef[] array dadx, dady, a0 values.
*/
static void setup_line_coefficients( struct lp_setup_context *setup,
struct lp_line_info *info)
{
const struct lp_setup_variant_key *key = &setup->setup.variant->key;
unsigned fragcoord_usage_mask = TGSI_WRITEMASK_XYZ;
unsigned slot;
/* setup interpolation for all the remaining attributes:
*/
for (slot = 0; slot < key->num_inputs; slot++) {
unsigned vert_attr = key->inputs[slot].src_index;
unsigned usage_mask = key->inputs[slot].usage_mask;
unsigned i;
switch (key->inputs[slot].interp) {
case LP_INTERP_CONSTANT:
if (key->flatshade_first) {
for (i = 0; i < NUM_CHANNELS; i++)
if (usage_mask & (1 << i))
constant_coef(setup, info, slot+1, info->v1[vert_attr][i], i);
}
else {
for (i = 0; i < NUM_CHANNELS; i++)
if (usage_mask & (1 << i))
constant_coef(setup, info, slot+1, info->v2[vert_attr][i], i);
}
break;
case LP_INTERP_LINEAR:
for (i = 0; i < NUM_CHANNELS; i++)
if (usage_mask & (1 << i))
linear_coef(setup, info, slot+1, vert_attr, i);
break;
case LP_INTERP_PERSPECTIVE:
for (i = 0; i < NUM_CHANNELS; i++)
if (usage_mask & (1 << i))
perspective_coef(setup, info, slot+1, vert_attr, i);
fragcoord_usage_mask |= TGSI_WRITEMASK_W;
break;
case LP_INTERP_POSITION:
/*
* The generated pixel interpolators will pick up the coeffs from
* slot 0, so all need to ensure that the usage mask is covers all
* usages.
*/
fragcoord_usage_mask |= usage_mask;
break;
case LP_INTERP_FACING:
for (i = 0; i < NUM_CHANNELS; i++)
if (usage_mask & (1 << i))
constant_coef(setup, info, slot+1, 1.0, i);
break;
default:
assert(0);
}
}
/* The internal position input is in slot zero:
*/
setup_fragcoord_coef(setup, info, 0,
fragcoord_usage_mask);
}
static INLINE int subpixel_snap( float a )
{
return util_iround(FIXED_ONE * a);
}
/**
* Print line vertex attribs (for debug).
*/
static void
print_line(struct lp_setup_context *setup,
const float (*v1)[4],
const float (*v2)[4])
{
const struct lp_setup_variant_key *key = &setup->setup.variant->key;
uint i;
debug_printf("llvmpipe line\n");
for (i = 0; i < 1 + key->num_inputs; i++) {
debug_printf(" v1[%d]: %f %f %f %f\n", i,
v1[i][0], v1[i][1], v1[i][2], v1[i][3]);
}
for (i = 0; i < 1 + key->num_inputs; i++) {
debug_printf(" v2[%d]: %f %f %f %f\n", i,
v2[i][0], v2[i][1], v2[i][2], v2[i][3]);
}
}
static INLINE boolean sign(float x){
return x >= 0;
}
/* Used on positive floats only:
*/
static INLINE float fracf(float f)
{
return f - floorf(f);
}
static boolean
try_setup_line( struct lp_setup_context *setup,
const float (*v1)[4],
const float (*v2)[4])
{
struct lp_scene *scene = setup->scene;
const struct lp_setup_variant_key *key = &setup->setup.variant->key;
struct lp_rast_triangle *line;
struct lp_rast_plane *plane;
struct lp_line_info info;
float width = MAX2(1.0, setup->line_width);
struct u_rect bbox;
unsigned tri_bytes;
int x[4];
int y[4];
int i;
int nr_planes = 4;
/* linewidth should be interpreted as integer */
int fixed_width = util_iround(width) * FIXED_ONE;
float x_offset=0;
float y_offset=0;
float x_offset_end=0;
float y_offset_end=0;
float x1diff;
float y1diff;
float x2diff;
float y2diff;
float dx, dy;
float area;
boolean draw_start;
boolean draw_end;
boolean will_draw_start;
boolean will_draw_end;
if (0)
print_line(setup, v1, v2);
if (setup->scissor_test) {
nr_planes = 8;
}
else {
nr_planes = 4;
}
dx = v1[0][0] - v2[0][0];
dy = v1[0][1] - v2[0][1];
area = (dx * dx + dy * dy);
if (area == 0) {
LP_COUNT(nr_culled_tris);
return TRUE;
}
info.oneoverarea = 1.0f / area;
info.dx = dx;
info.dy = dy;
info.v1 = v1;
info.v2 = v2;
/* X-MAJOR LINE */
if (fabsf(dx) >= fabsf(dy)) {
float dydx = dy / dx;
x1diff = v1[0][0] - (float) floor(v1[0][0]) - 0.5;
y1diff = v1[0][1] - (float) floor(v1[0][1]) - 0.5;
x2diff = v2[0][0] - (float) floor(v2[0][0]) - 0.5;
y2diff = v2[0][1] - (float) floor(v2[0][1]) - 0.5;
if (y2diff==-0.5 && dy<0){
y2diff = 0.5;
}
/*
* Diamond exit rule test for starting point
*/
if (fabsf(x1diff) + fabsf(y1diff) < 0.5) {
draw_start = TRUE;
}
else if (sign(x1diff) == sign(-dx)) {
draw_start = FALSE;
}
else if (sign(-y1diff) != sign(dy)) {
draw_start = TRUE;
}
else {
/* do intersection test */
float yintersect = fracf(v1[0][1]) + x1diff * dydx;
draw_start = (yintersect < 1.0 && yintersect > 0.0);
}
/*
* Diamond exit rule test for ending point
*/
if (fabsf(x2diff) + fabsf(y2diff) < 0.5) {
draw_end = FALSE;
}
else if (sign(x2diff) != sign(-dx)) {
draw_end = FALSE;
}
else if (sign(-y2diff) == sign(dy)) {
draw_end = TRUE;
}
else {
/* do intersection test */
float yintersect = fracf(v2[0][1]) + x2diff * dydx;
draw_end = (yintersect < 1.0 && yintersect > 0.0);
}
/* Are we already drawing start/end?
*/
will_draw_start = sign(-x1diff) != sign(dx);
will_draw_end = (sign(x2diff) == sign(-dx)) || x2diff==0;
if (dx < 0) {
/* if v2 is to the right of v1, swap pointers */
const float (*temp)[4] = v1;
v1 = v2;
v2 = temp;
dx = -dx;
dy = -dy;
/* Otherwise shift planes appropriately */
if (will_draw_start != draw_start) {
x_offset_end = - x1diff - 0.5;
y_offset_end = x_offset_end * dydx;
}
if (will_draw_end != draw_end) {
x_offset = - x2diff - 0.5;
y_offset = x_offset * dydx;
}
}
else{
/* Otherwise shift planes appropriately */
if (will_draw_start != draw_start) {
x_offset = - x1diff + 0.5;
y_offset = x_offset * dydx;
}
if (will_draw_end != draw_end) {
x_offset_end = - x2diff + 0.5;
y_offset_end = x_offset_end * dydx;
}
}
/* x/y positions in fixed point */
x[0] = subpixel_snap(v1[0][0] + x_offset - setup->pixel_offset);
x[1] = subpixel_snap(v2[0][0] + x_offset_end - setup->pixel_offset);
x[2] = subpixel_snap(v2[0][0] + x_offset_end - setup->pixel_offset);
x[3] = subpixel_snap(v1[0][0] + x_offset - setup->pixel_offset);
y[0] = subpixel_snap(v1[0][1] + y_offset - setup->pixel_offset) - fixed_width/2;
y[1] = subpixel_snap(v2[0][1] + y_offset_end - setup->pixel_offset) - fixed_width/2;
y[2] = subpixel_snap(v2[0][1] + y_offset_end - setup->pixel_offset) + fixed_width/2;
y[3] = subpixel_snap(v1[0][1] + y_offset - setup->pixel_offset) + fixed_width/2;
}
else {
const float dxdy = dx / dy;
/* Y-MAJOR LINE */
x1diff = v1[0][0] - (float) floor(v1[0][0]) - 0.5;
y1diff = v1[0][1] - (float) floor(v1[0][1]) - 0.5;
x2diff = v2[0][0] - (float) floor(v2[0][0]) - 0.5;
y2diff = v2[0][1] - (float) floor(v2[0][1]) - 0.5;
if (x2diff==-0.5 && dx<0) {
x2diff = 0.5;
}
/*
* Diamond exit rule test for starting point
*/
if (fabsf(x1diff) + fabsf(y1diff) < 0.5) {
draw_start = TRUE;
}
else if (sign(-y1diff) == sign(dy)) {
draw_start = FALSE;
}
else if (sign(x1diff) != sign(-dx)) {
draw_start = TRUE;
}
else {
/* do intersection test */
float xintersect = fracf(v1[0][0]) + y1diff * dxdy;
draw_start = (xintersect < 1.0 && xintersect > 0.0);
}
/*
* Diamond exit rule test for ending point
*/
if (fabsf(x2diff) + fabsf(y2diff) < 0.5) {
draw_end = FALSE;
}
else if (sign(-y2diff) != sign(dy) ) {
draw_end = FALSE;
}
else if (sign(x2diff) == sign(-dx) ) {
draw_end = TRUE;
}
else {
/* do intersection test */
float xintersect = fracf(v2[0][0]) + y2diff * dxdy;
draw_end = (xintersect < 1.0 && xintersect >= 0.0);
}
/* Are we already drawing start/end?
*/
will_draw_start = sign(y1diff) == sign(dy);
will_draw_end = (sign(-y2diff) == sign(dy)) || y2diff==0;
if (dy > 0) {
/* if v2 is on top of v1, swap pointers */
const float (*temp)[4] = v1;
v1 = v2;
v2 = temp;
dx = -dx;
dy = -dy;
/* Otherwise shift planes appropriately */
if (will_draw_start != draw_start) {
y_offset_end = - y1diff + 0.5;
x_offset_end = y_offset_end * dxdy;
}
if (will_draw_end != draw_end) {
y_offset = - y2diff + 0.5;
x_offset = y_offset * dxdy;
}
}
else {
/* Otherwise shift planes appropriately */
if (will_draw_start != draw_start) {
y_offset = - y1diff - 0.5;
x_offset = y_offset * dxdy;
}
if (will_draw_end != draw_end) {
y_offset_end = - y2diff - 0.5;
x_offset_end = y_offset_end * dxdy;
}
}
/* x/y positions in fixed point */
x[0] = subpixel_snap(v1[0][0] + x_offset - setup->pixel_offset) - fixed_width/2;
x[1] = subpixel_snap(v2[0][0] + x_offset_end - setup->pixel_offset) - fixed_width/2;
x[2] = subpixel_snap(v2[0][0] + x_offset_end - setup->pixel_offset) + fixed_width/2;
x[3] = subpixel_snap(v1[0][0] + x_offset - setup->pixel_offset) + fixed_width/2;
y[0] = subpixel_snap(v1[0][1] + y_offset - setup->pixel_offset);
y[1] = subpixel_snap(v2[0][1] + y_offset_end - setup->pixel_offset);
y[2] = subpixel_snap(v2[0][1] + y_offset_end - setup->pixel_offset);
y[3] = subpixel_snap(v1[0][1] + y_offset - setup->pixel_offset);
}
LP_COUNT(nr_tris);
/* Bounding rectangle (in pixels) */
{
/* Yes this is necessary to accurately calculate bounding boxes
* with the two fill-conventions we support. GL (normally) ends
* up needing a bottom-left fill convention, which requires
* slightly different rounding.
*/
int adj = (setup->pixel_offset != 0) ? 1 : 0;
bbox.x0 = (MIN4(x[0], x[1], x[2], x[3]) + (FIXED_ONE-1)) >> FIXED_ORDER;
bbox.x1 = (MAX4(x[0], x[1], x[2], x[3]) + (FIXED_ONE-1)) >> FIXED_ORDER;
bbox.y0 = (MIN4(y[0], y[1], y[2], y[3]) + (FIXED_ONE-1) + adj) >> FIXED_ORDER;
bbox.y1 = (MAX4(y[0], y[1], y[2], y[3]) + (FIXED_ONE-1) + adj) >> FIXED_ORDER;
/* Inclusive coordinates:
*/
bbox.x1--;
bbox.y1--;
}
if (bbox.x1 < bbox.x0 ||
bbox.y1 < bbox.y0) {
if (0) debug_printf("empty bounding box\n");
LP_COUNT(nr_culled_tris);
return TRUE;
}
if (!u_rect_test_intersection(&setup->draw_region, &bbox)) {
if (0) debug_printf("offscreen\n");
LP_COUNT(nr_culled_tris);
return TRUE;
}
/* Can safely discard negative regions:
*/
bbox.x0 = MAX2(bbox.x0, 0);
bbox.y0 = MAX2(bbox.y0, 0);
line = lp_setup_alloc_triangle(scene,
key->num_inputs,
nr_planes,
&tri_bytes);
if (!line)
return FALSE;
#ifdef DEBUG
line->v[0][0] = v1[0][0];
line->v[1][0] = v2[0][0];
line->v[0][1] = v1[0][1];
line->v[1][1] = v2[0][1];
#endif
/* calculate the deltas */
plane = GET_PLANES(line);
plane[0].dcdy = x[0] - x[1];
plane[1].dcdy = x[1] - x[2];
plane[2].dcdy = x[2] - x[3];
plane[3].dcdy = x[3] - x[0];
plane[0].dcdx = y[0] - y[1];
plane[1].dcdx = y[1] - y[2];
plane[2].dcdx = y[2] - y[3];
plane[3].dcdx = y[3] - y[0];
/* Setup parameter interpolants:
*/
info.a0 = GET_A0(&line->inputs);
info.dadx = GET_DADX(&line->inputs);
info.dady = GET_DADY(&line->inputs);
setup_line_coefficients(setup, &info);
line->inputs.frontfacing = TRUE;
line->inputs.disable = FALSE;
line->inputs.opaque = FALSE;
for (i = 0; i < 4; i++) {
/* half-edge constants, will be interated over the whole render
* target.
*/
plane[i].c = plane[i].dcdx * x[i] - plane[i].dcdy * y[i];
/* correct for top-left vs. bottom-left fill convention.
*
* note that we're overloading gl_rasterization_rules to mean
* both (0.5,0.5) pixel centers *and* bottom-left filling
* convention.
*
* GL actually has a top-left filling convention, but GL's
* notion of "top" differs from gallium's...
*
* Also, sometimes (in FBO cases) GL will render upside down
* to its usual method, in which case it will probably want
* to use the opposite, top-left convention.
*/
if (plane[i].dcdx < 0) {
/* both fill conventions want this - adjust for left edges */
plane[i].c++;
}
else if (plane[i].dcdx == 0) {
if (setup->pixel_offset == 0) {
/* correct for top-left fill convention:
*/
if (plane[i].dcdy > 0) plane[i].c++;
}
else {
/* correct for bottom-left fill convention:
*/
if (plane[i].dcdy < 0) plane[i].c++;
}
}
plane[i].dcdx *= FIXED_ONE;
plane[i].dcdy *= 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.
*/
plane[i].eo = 0;
if (plane[i].dcdx < 0) plane[i].eo -= plane[i].dcdx;
if (plane[i].dcdy > 0) plane[i].eo += plane[i].dcdy;
}
/*
* When rasterizing scissored tris, use the intersection of the
* triangle bounding box and the scissor rect to generate the
* scissor planes.
*
* This permits us to cut off the triangle "tails" that are present
* in the intermediate recursive levels caused when two of the
* triangles edges don't diverge quickly enough to trivially reject
* exterior blocks from the triangle.
*
* It's not really clear if it's worth worrying about these tails,
* but since we generate the planes for each scissored tri, it's
* free to trim them in this case.
*
* Note that otherwise, the scissor planes only vary in 'C' value,
* and even then only on state-changes. Could alternatively store
* these planes elsewhere.
*/
if (nr_planes == 8) {
const struct u_rect *scissor = &setup->scissor;
plane[4].dcdx = -1;
plane[4].dcdy = 0;
plane[4].c = 1-scissor->x0;
plane[4].eo = 1;
plane[5].dcdx = 1;
plane[5].dcdy = 0;
plane[5].c = scissor->x1+1;
plane[5].eo = 0;
plane[6].dcdx = 0;
plane[6].dcdy = 1;
plane[6].c = 1-scissor->y0;
plane[6].eo = 1;
plane[7].dcdx = 0;
plane[7].dcdy = -1;
plane[7].c = scissor->y1+1;
plane[7].eo = 0;
}
return lp_setup_bin_triangle(setup, line, &bbox, nr_planes);
}
static void lp_setup_line( struct lp_setup_context *setup,
const float (*v0)[4],
const float (*v1)[4] )
{
if (!try_setup_line( setup, v0, v1 ))
{
if (!lp_setup_flush_and_restart(setup))
return;
if (!try_setup_line( setup, v0, v1 ))
return;
}
}
void lp_setup_choose_line( struct lp_setup_context *setup )
{
setup->line = lp_setup_line;
}