/*
* Copyright © 2015 Red Hat
*
* 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, sublicense,
* 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 NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS 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.
*/
#include "nir.h"
#include "nir_builder.h"
/* Lower glDrawPixels().
*
* This is based on the logic in st_get_drawpix_shader() in TGSI compiler.
*
* Run before nir_lower_io.
*/
typedef struct {
const nir_lower_drawpixels_options *options;
nir_shader *shader;
nir_builder b;
nir_variable *texcoord, *scale, *bias;
} lower_drawpixels_state;
static nir_ssa_def *
get_texcoord(lower_drawpixels_state *state)
{
if (state->texcoord == NULL) {
nir_variable *texcoord = NULL;
/* find gl_TexCoord, if it exists: */
nir_foreach_variable(var, &state->shader->inputs) {
if (var->data.location == VARYING_SLOT_TEX0) {
texcoord = var;
break;
}
}
/* otherwise create it: */
if (texcoord == NULL) {
texcoord = nir_variable_create(state->shader,
nir_var_shader_in,
glsl_vec4_type(),
"gl_TexCoord");
texcoord->data.location = VARYING_SLOT_TEX0;
}
state->texcoord = texcoord;
}
return nir_load_var(&state->b, state->texcoord);
}
static nir_variable *
create_uniform(nir_shader *shader, const char *name, const int state_tokens[5])
{
nir_variable *var = nir_variable_create(shader,
nir_var_uniform,
glsl_vec4_type(),
name);
var->num_state_slots = 1;
var->state_slots = ralloc_array(var, nir_state_slot, 1);
memcpy(var->state_slots[0].tokens, state_tokens,
sizeof(var->state_slots[0].tokens));
return var;
}
static nir_ssa_def *
get_scale(lower_drawpixels_state *state)
{
if (state->scale == NULL) {
state->scale = create_uniform(state->shader, "gl_PTscale",
state->options->scale_state_tokens);
}
return nir_load_var(&state->b, state->scale);
}
static nir_ssa_def *
get_bias(lower_drawpixels_state *state)
{
if (state->bias == NULL) {
state->bias = create_uniform(state->shader, "gl_PTbias",
state->options->bias_state_tokens);
}
return nir_load_var(&state->b, state->bias);
}
static nir_ssa_def *
get_texcoord_const(lower_drawpixels_state *state)
{
if (state->bias == NULL) {
state->bias = create_uniform(state->shader, "gl_MultiTexCoord0",
state->options->texcoord_state_tokens);
}
return nir_load_var(&state->b, state->bias);
}
static void
lower_color(lower_drawpixels_state *state, nir_intrinsic_instr *intr)
{
nir_builder *b = &state->b;
nir_ssa_def *texcoord;
nir_tex_instr *tex;
nir_ssa_def *def;
assert(intr->dest.is_ssa);
b->cursor = nir_before_instr(&intr->instr);
texcoord = get_texcoord(state);
/* replace load_var(gl_Color) w/ texture sample:
* TEX def, texcoord, drawpix_sampler, 2D
*/
tex = nir_tex_instr_create(state->shader, 1);
tex->op = nir_texop_tex;
tex->sampler_dim = GLSL_SAMPLER_DIM_2D;
tex->coord_components = 2;
tex->sampler_index = state->options->drawpix_sampler;
tex->texture_index = state->options->drawpix_sampler;
tex->dest_type = nir_type_float;
tex->src[0].src_type = nir_tex_src_coord;
tex->src[0].src =
nir_src_for_ssa(nir_channels(b, texcoord,
(1 << tex->coord_components) - 1));
nir_ssa_dest_init(&tex->instr, &tex->dest, 4, 32, NULL);
nir_builder_instr_insert(b, &tex->instr);
def = &tex->dest.ssa;
/* Apply the scale and bias. */
if (state->options->scale_and_bias) {
/* MAD def, def, scale, bias; */
def = nir_ffma(b, def, get_scale(state), get_bias(state));
}
if (state->options->pixel_maps) {
static const unsigned swiz_xy[4] = {0,1};
static const unsigned swiz_zw[4] = {2,3};
/* do four pixel map look-ups with two TEX instructions: */
nir_ssa_def *def_xy, *def_zw;
/* TEX def.xy, def.xyyy, pixelmap_sampler, 2D; */
tex = nir_tex_instr_create(state->shader, 1);
tex->op = nir_texop_tex;
tex->sampler_dim = GLSL_SAMPLER_DIM_2D;
tex->coord_components = 2;
tex->sampler_index = state->options->pixelmap_sampler;
tex->texture_index = state->options->pixelmap_sampler;
tex->dest_type = nir_type_float;
tex->src[0].src_type = nir_tex_src_coord;
tex->src[0].src = nir_src_for_ssa(nir_swizzle(b, def, swiz_xy, 2, true));
nir_ssa_dest_init(&tex->instr, &tex->dest, 4, 32, NULL);
nir_builder_instr_insert(b, &tex->instr);
def_xy = &tex->dest.ssa;
/* TEX def.zw, def.zwww, pixelmap_sampler, 2D; */
tex = nir_tex_instr_create(state->shader, 1);
tex->op = nir_texop_tex;
tex->sampler_dim = GLSL_SAMPLER_DIM_2D;
tex->coord_components = 2;
tex->sampler_index = state->options->pixelmap_sampler;
tex->dest_type = nir_type_float;
tex->src[0].src_type = nir_tex_src_coord;
tex->src[0].src = nir_src_for_ssa(nir_swizzle(b, def, swiz_zw, 2, true));
nir_ssa_dest_init(&tex->instr, &tex->dest, 4, 32, NULL);
nir_builder_instr_insert(b, &tex->instr);
def_zw = &tex->dest.ssa;
/* def = vec4(def.xy, def.zw); */
def = nir_vec4(b,
nir_channel(b, def_xy, 0),
nir_channel(b, def_xy, 1),
nir_channel(b, def_zw, 0),
nir_channel(b, def_zw, 1));
}
nir_ssa_def_rewrite_uses(&intr->dest.ssa, nir_src_for_ssa(def));
}
static void
lower_texcoord(lower_drawpixels_state *state, nir_intrinsic_instr *intr)
{
state->b.cursor = nir_before_instr(&intr->instr);
nir_ssa_def *texcoord_const = get_texcoord_const(state);
nir_ssa_def_rewrite_uses(&intr->dest.ssa, nir_src_for_ssa(texcoord_const));
}
static bool
lower_drawpixels_block(lower_drawpixels_state *state, nir_block *block)
{
nir_foreach_instr_safe(instr, block) {
if (instr->type == nir_instr_type_intrinsic) {
nir_intrinsic_instr *intr = nir_instr_as_intrinsic(instr);
if (intr->intrinsic == nir_intrinsic_load_var) {
nir_deref_var *dvar = intr->variables[0];
nir_variable *var = dvar->var;
if (var->data.location == VARYING_SLOT_COL0) {
/* gl_Color should not have array/struct derefs: */
assert(dvar->deref.child == NULL);
lower_color(state, intr);
} else if (var->data.location == VARYING_SLOT_TEX0) {
/* gl_TexCoord should not have array/struct derefs: */
assert(dvar->deref.child == NULL);
lower_texcoord(state, intr);
}
}
}
}
return true;
}
static void
lower_drawpixels_impl(lower_drawpixels_state *state, nir_function_impl *impl)
{
nir_builder_init(&state->b, impl);
nir_foreach_block(block, impl) {
lower_drawpixels_block(state, block);
}
nir_metadata_preserve(impl, nir_metadata_block_index |
nir_metadata_dominance);
}
void
nir_lower_drawpixels(nir_shader *shader,
const nir_lower_drawpixels_options *options)
{
lower_drawpixels_state state = {
.options = options,
.shader = shader,
};
assert(shader->info.stage == MESA_SHADER_FRAGMENT);
nir_foreach_function(function, shader) {
if (function->impl)
lower_drawpixels_impl(&state, function->impl);
}
}