src/compiler/nir/nir_lower_drawpixels.c - platform/external/mesa3d - Git at Google

 /*
  * 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_variable *texcoord, *texcoord_const, *scale, *bias, *tex, *pixelmap;
 } lower_drawpixels_state;

 static nir_ssa_def *
 get_texcoord(nir_builder *b, lower_drawpixels_state *state)
 {
    if (state->texcoord == NULL) {
       state->texcoord = nir_get_variable_with_location(state->shader, nir_var_shader_in,
                                                        VARYING_SLOT_TEX0, glsl_vec4_type());
    }
    return nir_load_var(b, state->texcoord);
 }

 static nir_variable *
 create_uniform(nir_shader *shader, const char *name,
                const gl_state_index16 state_tokens[STATE_LENGTH])
 {
    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(nir_builder *b, 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(b, state->scale);
 }

 static nir_ssa_def *
 get_bias(nir_builder *b, 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(b, state->bias);
 }

 static nir_ssa_def *
 get_texcoord_const(nir_builder *b, lower_drawpixels_state *state)
 {
    if (state->texcoord_const == NULL) {
       state->texcoord_const = create_uniform(state->shader,
                                    "gl_MultiTexCoord0",
                                    state->options->texcoord_state_tokens);
    }
    return nir_load_var(b, state->texcoord_const);
 }

 static bool
 lower_color(nir_builder *b, lower_drawpixels_state *state, nir_intrinsic_instr *intr)
 {
    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(b, state);

    const struct glsl_type *sampler2D =
       glsl_sampler_type(GLSL_SAMPLER_DIM_2D, false, false, GLSL_TYPE_FLOAT);

    if (!state->tex) {
       state->tex =
          nir_variable_create(b->shader, nir_var_uniform, sampler2D, "drawpix");
       state->tex->data.binding = state->options->drawpix_sampler;
       state->tex->data.explicit_binding = true;
       state->tex->data.how_declared = nir_var_hidden;
    }

    nir_deref_instr *tex_deref = nir_build_deref_var(b, state->tex);

    /* replace load_var(gl_Color) w/ texture sample:
     *   TEX def, texcoord, drawpix_sampler, 2D
     */
    tex = nir_tex_instr_create(state->shader, 3);
    tex->op = nir_texop_tex;
    tex->sampler_dim = GLSL_SAMPLER_DIM_2D;
    tex->coord_components = 2;
    tex->dest_type = nir_type_float32;
    tex->src[0].src_type = nir_tex_src_texture_deref;
    tex->src[0].src = nir_src_for_ssa(&tex_deref->dest.ssa);
    tex->src[1].src_type = nir_tex_src_sampler_deref;
    tex->src[1].src = nir_src_for_ssa(&tex_deref->dest.ssa);
    tex->src[2].src_type = nir_tex_src_coord;
    tex->src[2].src =
       nir_src_for_ssa(nir_channels(b, texcoord,
                                    (1 << tex->coord_components) - 1));

    nir_ssa_dest_init(&tex->instr, &tex->dest, 4, 32);
    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(b, state), get_bias(b, state));
    }

    if (state->options->pixel_maps) {
       if (!state->pixelmap) {
          state->pixelmap = nir_variable_create(b->shader, nir_var_uniform,
                                                sampler2D, "pixelmap");
          state->pixelmap->data.binding = state->options->pixelmap_sampler;
          state->pixelmap->data.explicit_binding = true;
          state->pixelmap->data.how_declared = nir_var_hidden;
       }

       nir_deref_instr *pixelmap_deref =
          nir_build_deref_var(b, state->pixelmap);

       /* 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, 3);
       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_float32;
       tex->src[0].src_type = nir_tex_src_texture_deref;
       tex->src[0].src = nir_src_for_ssa(&pixelmap_deref->dest.ssa);
       tex->src[1].src_type = nir_tex_src_sampler_deref;
       tex->src[1].src = nir_src_for_ssa(&pixelmap_deref->dest.ssa);
       tex->src[2].src_type = nir_tex_src_coord;
       tex->src[2].src = nir_src_for_ssa(nir_channels(b, def, 0x3));

       nir_ssa_dest_init(&tex->instr, &tex->dest, 4, 32);
       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_float32;
       tex->src[0].src_type = nir_tex_src_coord;
       tex->src[0].src = nir_src_for_ssa(nir_channels(b, def, 0xc));

       nir_ssa_dest_init(&tex->instr, &tex->dest, 4, 32);
       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, def);
    return true;
 }

 static bool
 lower_texcoord(nir_builder *b, lower_drawpixels_state *state, nir_intrinsic_instr *intr)
 {
    b->cursor = nir_before_instr(&intr->instr);

    nir_ssa_def *texcoord_const = get_texcoord_const(b, state);
    nir_ssa_def_rewrite_uses(&intr->dest.ssa, texcoord_const);
    return true;
 }

 static bool
 lower_drawpixels_instr(nir_builder *b, nir_instr *instr, void *cb_data)
 {
    lower_drawpixels_state *state = cb_data;
    if (instr->type != nir_instr_type_intrinsic)
       return false;

    nir_intrinsic_instr *intr = nir_instr_as_intrinsic(instr);

    switch (intr->intrinsic) {
    case nir_intrinsic_load_deref: {
       nir_deref_instr *deref = nir_src_as_deref(intr->src[0]);
       nir_variable *var = nir_deref_instr_get_variable(deref);

       if (var->data.location == VARYING_SLOT_COL0) {
          /* gl_Color should not have array/struct derefs: */
          assert(deref->deref_type == nir_deref_type_var);
          return lower_color(b, state, intr);
       } else if (var->data.location == VARYING_SLOT_TEX0) {
          /* gl_TexCoord should not have array/struct derefs: */
          assert(deref->deref_type == nir_deref_type_var);
          return lower_texcoord(b, state, intr);
       }
       break;
    }

    case nir_intrinsic_load_color0:
       return lower_color(b, state, intr);

    case nir_intrinsic_load_interpolated_input:
    case nir_intrinsic_load_input: {
       if (nir_intrinsic_io_semantics(intr).location == VARYING_SLOT_TEX0)
          return lower_texcoord(b, state, intr);
       break;
    }
    default:
       break;
    }

    return false;
 }

 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_shader_instructions_pass(shader, lower_drawpixels_instr,
                                 nir_metadata_block_index |
                                 nir_metadata_dominance,
                                 &state);
 }
	/*
	* 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_variable texcoord, texcoord_const, scale, bias, tex, pixelmap;
	} lower_drawpixels_state;

	static nir_ssa_def *
	get_texcoord(nir_builder b, lower_drawpixels_state state)
	{
	if (state->texcoord == NULL) {
	state->texcoord = nir_get_variable_with_location(state->shader, nir_var_shader_in,
	VARYING_SLOT_TEX0, glsl_vec4_type());
	}
	return nir_load_var(b, state->texcoord);
	}

	static nir_variable *
	create_uniform(nir_shader shader, const char name,
	const gl_state_index16 state_tokens[STATE_LENGTH])
	{
	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(nir_builder b, 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(b, state->scale);
	}

	static nir_ssa_def *
	get_bias(nir_builder b, 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(b, state->bias);
	}

	static nir_ssa_def *
	get_texcoord_const(nir_builder b, lower_drawpixels_state state)
	{
	if (state->texcoord_const == NULL) {
	state->texcoord_const = create_uniform(state->shader,
	"gl_MultiTexCoord0",
	state->options->texcoord_state_tokens);
	}
	return nir_load_var(b, state->texcoord_const);
	}

	static bool
	lower_color(nir_builder b, lower_drawpixels_state state, nir_intrinsic_instr *intr)
	{
	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(b, state);

	const struct glsl_type *sampler2D =
	glsl_sampler_type(GLSL_SAMPLER_DIM_2D, false, false, GLSL_TYPE_FLOAT);

	if (!state->tex) {
	state->tex =
	nir_variable_create(b->shader, nir_var_uniform, sampler2D, "drawpix");
	state->tex->data.binding = state->options->drawpix_sampler;
	state->tex->data.explicit_binding = true;
	state->tex->data.how_declared = nir_var_hidden;
	}

	nir_deref_instr *tex_deref = nir_build_deref_var(b, state->tex);

	/* replace load_var(gl_Color) w/ texture sample:
	* TEX def, texcoord, drawpix_sampler, 2D
	*/
	tex = nir_tex_instr_create(state->shader, 3);
	tex->op = nir_texop_tex;
	tex->sampler_dim = GLSL_SAMPLER_DIM_2D;
	tex->coord_components = 2;
	tex->dest_type = nir_type_float32;
	tex->src[0].src_type = nir_tex_src_texture_deref;
	tex->src[0].src = nir_src_for_ssa(&tex_deref->dest.ssa);
	tex->src[1].src_type = nir_tex_src_sampler_deref;
	tex->src[1].src = nir_src_for_ssa(&tex_deref->dest.ssa);
	tex->src[2].src_type = nir_tex_src_coord;
	tex->src[2].src =
	nir_src_for_ssa(nir_channels(b, texcoord,
	(1 << tex->coord_components) - 1));

	nir_ssa_dest_init(&tex->instr, &tex->dest, 4, 32);
	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(b, state), get_bias(b, state));
	}

	if (state->options->pixel_maps) {
	if (!state->pixelmap) {
	state->pixelmap = nir_variable_create(b->shader, nir_var_uniform,
	sampler2D, "pixelmap");
	state->pixelmap->data.binding = state->options->pixelmap_sampler;
	state->pixelmap->data.explicit_binding = true;
	state->pixelmap->data.how_declared = nir_var_hidden;
	}

	nir_deref_instr *pixelmap_deref =
	nir_build_deref_var(b, state->pixelmap);

	/* 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, 3);
	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_float32;
	tex->src[0].src_type = nir_tex_src_texture_deref;
	tex->src[0].src = nir_src_for_ssa(&pixelmap_deref->dest.ssa);
	tex->src[1].src_type = nir_tex_src_sampler_deref;
	tex->src[1].src = nir_src_for_ssa(&pixelmap_deref->dest.ssa);
	tex->src[2].src_type = nir_tex_src_coord;
	tex->src[2].src = nir_src_for_ssa(nir_channels(b, def, 0x3));

	nir_ssa_dest_init(&tex->instr, &tex->dest, 4, 32);
	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_float32;
	tex->src[0].src_type = nir_tex_src_coord;
	tex->src[0].src = nir_src_for_ssa(nir_channels(b, def, 0xc));

	nir_ssa_dest_init(&tex->instr, &tex->dest, 4, 32);
	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, def);
	return true;
	}

	static bool
	lower_texcoord(nir_builder b, lower_drawpixels_state state, nir_intrinsic_instr *intr)
	{
	b->cursor = nir_before_instr(&intr->instr);

	nir_ssa_def *texcoord_const = get_texcoord_const(b, state);
	nir_ssa_def_rewrite_uses(&intr->dest.ssa, texcoord_const);
	return true;
	}

	static bool
	lower_drawpixels_instr(nir_builder b, nir_instr instr, void *cb_data)
	{
	lower_drawpixels_state *state = cb_data;
	if (instr->type != nir_instr_type_intrinsic)
	return false;

	nir_intrinsic_instr *intr = nir_instr_as_intrinsic(instr);

	switch (intr->intrinsic) {
	case nir_intrinsic_load_deref: {
	nir_deref_instr *deref = nir_src_as_deref(intr->src[0]);
	nir_variable *var = nir_deref_instr_get_variable(deref);

	if (var->data.location == VARYING_SLOT_COL0) {
	/* gl_Color should not have array/struct derefs: */
	assert(deref->deref_type == nir_deref_type_var);
	return lower_color(b, state, intr);
	} else if (var->data.location == VARYING_SLOT_TEX0) {
	/* gl_TexCoord should not have array/struct derefs: */
	assert(deref->deref_type == nir_deref_type_var);
	return lower_texcoord(b, state, intr);
	}
	break;
	}

	case nir_intrinsic_load_color0:
	return lower_color(b, state, intr);

	case nir_intrinsic_load_interpolated_input:
	case nir_intrinsic_load_input: {
	if (nir_intrinsic_io_semantics(intr).location == VARYING_SLOT_TEX0)
	return lower_texcoord(b, state, intr);
	break;
	}
	default:
	break;
	}

	return false;
	}

	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_shader_instructions_pass(shader, lower_drawpixels_instr,
	nir_metadata_block_index \|
	nir_metadata_dominance,
	&state);
	}