/**
* 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_point_fragcoord_coef(struct lp_setup_context *setup,
struct point_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) {
constant_coef(setup, info, slot, info->v0[0][2], 2);
}
/*W*/
if (usage_mask & TGSI_WRITEMASK_W) {
constant_coef(setup, info, slot, info->v0[0][3], 3);
}
}
/**
* Setup the fragment input attribute with the front-facing value.
* \param frontface is the triangle front facing?
*/
static void setup_facing_coef( struct lp_rast_shader_inputs *inputs,
unsigned slot,
boolean frontface,
unsigned usage_mask)
{
/* convert TRUE to 1.0 and FALSE to -1.0 */
if (usage_mask & TGSI_WRITEMASK_X)
constant_coef( inputs, slot, 2.0f * frontface - 1.0f, 0 );
if (usage_mask & TGSI_WRITEMASK_Y)
constant_coef( inputs, slot, 0.0f, 1 ); /* wasted */
if (usage_mask & TGSI_WRITEMASK_Z)
constant_coef( inputs, slot, 0.0f, 2 ); /* wasted */
if (usage_mask & TGSI_WRITEMASK_W)
constant_coef( inputs, slot, 0.0f, 3 ); /* wasted */
}
/**
* 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,
info->frontfacing ? 1.0f : -1.0f, i);
break;
default:
assert(0);
}
}
/* The internal position input is in slot zero:
*/
setup_fragcoord_coef(setup, info, 0,
fragcoord_usage_mask);
}
/**
* Compute the point->coef[] array dadx, dady, a0 values.
*/
static void
setup_point_coefficients( struct lp_setup_context *setup,
struct point_info *info)
{
const struct lp_setup_variant_key *key = &setup->setup.variant->key;
const struct lp_fragment_shader *shader = setup->fs.current.variant->shader;
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;
enum lp_interp interp = key->inputs[slot].interp;
boolean perspective = !!(interp == LP_INTERP_PERSPECTIVE);
unsigned i;
if (perspective & usage_mask) {
fragcoord_usage_mask |= TGSI_WRITEMASK_W;
}
switch (interp) {
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_LINEAR:
/* Sprite tex coords may use linear interpolation someday */
/* fall-through */
case LP_INTERP_PERSPECTIVE:
/* check if the sprite coord flag is set for this attribute.
* If so, set it up so it up so x and y vary from 0 to 1.
*/
if (shader->info.base.input_semantic_name[slot] == TGSI_SEMANTIC_GENERIC) {
unsigned semantic_index = shader->info.base.input_semantic_index[slot];
/* Note that sprite_coord enable is a bitfield of
* PIPE_MAX_SHADER_OUTPUTS bits.
*/
if (semantic_index < PIPE_MAX_SHADER_OUTPUTS &&
(setup->sprite_coord_enable & (1 << semantic_index))) {
for (i = 0; i < NUM_CHANNELS; i++) {
if (usage_mask & (1 << i)) {
texcoord_coef(setup, info, slot + 1, i,
setup->sprite_coord_origin,
perspective);
}
}
break;
}
}
/* fall-through */
case LP_INTERP_CONSTANT:
for (i = 0; i < NUM_CHANNELS; i++) {
if (usage_mask & (1 << i)) {
if (perspective) {
point_persp_coeff(setup, info, slot+1, i);
}
else {
constant_coef(setup, info, slot+1, info->v0[vert_attr][i], i);
}
}
}
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);
break;
}
}
/* The internal position input is in slot zero:
*/
setup_point_fragcoord_coef(setup, info, 0,
fragcoord_usage_mask);
}
/**
* Compute the tri->coef[] array dadx, dady, a0 values.
*/
void lp_setup_tri_coef( struct lp_setup_context *setup,
struct lp_rast_shader_inputs *inputs,
const float (*v0)[4],
const float (*v1)[4],
const float (*v2)[4],
boolean frontfacing)
{
unsigned fragcoord_usage_mask = TGSI_WRITEMASK_XYZ;
unsigned slot;
unsigned i;
struct lp_tri_info info;
float dx01 = v0[0][0] - v1[0][0];
float dy01 = v0[0][1] - v1[0][1];
float dx20 = v2[0][0] - v0[0][0];
float dy20 = v2[0][1] - v0[0][1];
float oneoverarea = 1.0f / (dx01 * dy20 - dx20 * dy01);
info.v0 = v0;
info.v1 = v1;
info.v2 = v2;
info.frontfacing = frontfacing;
info.x0_center = v0[0][0] - setup->pixel_offset;
info.y0_center = v0[0][1] - setup->pixel_offset;
info.dx01_ooa = dx01 * oneoverarea;
info.dx20_ooa = dx20 * oneoverarea;
info.dy01_ooa = dy01 * oneoverarea;
info.dy20_ooa = dy20 * oneoverarea;
/* 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 usage_mask = setup->fs.input[slot].usage_mask;
switch (setup->fs.input[slot].interp) {
case LP_INTERP_CONSTANT:
if (setup->flatshade_first) {
for (i = 0; i < NUM_CHANNELS; i++)
if (usage_mask & (1 << i))
constant_coef(inputs, slot+1, info.v0[vert_attr][i], i);
}
else {
for (i = 0; i < NUM_CHANNELS; i++)
if (usage_mask & (1 << i))
constant_coef(inputs, 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(inputs, &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(inputs, &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:
setup_facing_coef(inputs, slot+1, info.frontfacing, usage_mask);
break;
default:
assert(0);
}
}
/* The internal position input is in slot zero:
*/
setup_fragcoord_coef(inputs, &info, 0, fragcoord_usage_mask);
}