<div dir="ltr"> <div class="gmail_extra"> <div class="gmail_quote">On Mon, May 9, 2016 at 12:33 PM, Rob Clark <<a href="mailto:robdclark@gmail.com" target="_blank">robdclark@gmail.com</a>> wrote: <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">From: Rob Clark <<a href="mailto:robclark@freedesktop.org">robclark@freedesktop.org</a>> Signed-off-by: Rob Clark <<a href="mailto:robclark@freedesktop.org">robclark@freedesktop.org</a>> Reviewed-by: Connor Abbott <<a href="mailto:cwabbott0@gmail.com">cwabbott0@gmail.com</a>> --- src/compiler/Makefile.sources | 1 + src/compiler/nir/nir.h | 11 + src/compiler/nir/nir_lower_wpos_ytransform.c | 310 +++++++++++++++++++++++++++ 3 files changed, 322 insertions(+) create mode 100644 src/compiler/nir/nir_lower_wpos_ytransform.c diff --git a/src/compiler/Makefile.sources b/src/compiler/Makefile.sources index 2a52319..b542a1a 100644 --- a/src/compiler/Makefile.sources +++ b/src/compiler/Makefile.sources @@ -208,6 +208,7 @@ NIR_FILES = \ nir/nir_lower_vars_to_ssa.c \ nir/nir_lower_var_copies.c \ nir/nir_lower_vec_to_movs.c \ + nir/nir_lower_wpos_ytransform.c \ nir/nir_metadata.c \ nir/nir_move_vec_src_uses_to_dest.c \ nir/nir_normalize_cubemap_coords.c \ diff --git a/src/compiler/nir/nir.h b/src/compiler/nir/nir.h index 8a616d4..474ba63 100644 --- a/src/compiler/nir/nir.h +++ b/src/compiler/nir/nir.h @@ -2374,6 +2374,17 @@ void nir_lower_two_sided_color(nir_shader *shader); void nir_lower_clamp_color_outputs(nir_shader *shader); +typedef struct nir_lower_wpos_ytransform_options { + int state_tokens[5]; + bool fs_coord_origin_upper_left :1; + bool fs_coord_origin_lower_left :1; + bool fs_coord_pixel_center_integer :1; + bool fs_coord_pixel_center_half_integer :1; </blockquote><div> </div><div>Drive-by commentary: Why are we using two booleans for one boolean here? All hardware should be either lower-left or upper-left and I'm going to hazard that the other two are mutually exclusive as well. The pass certainly seems to assume so. </div><div>Let's just make it two booleans. If we come across hardware that puts the pixel center at 0.75, 0.25 then we can make fs_coord_pixel_center an enum. </div><div>--Jason </div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> +} nir_lower_wpos_ytransform_options; + +bool nir_lower_wpos_ytransform(nir_shader *shader, + const nir_lower_wpos_ytransform_options *options); + void nir_lower_atomics(nir_shader *shader, const struct gl_shader_program *shader_program); void nir_lower_to_source_mods(nir_shader *shader); diff --git a/src/compiler/nir/nir_lower_wpos_ytransform.c b/src/compiler/nir/nir_lower_wpos_ytransform.c new file mode 100644 index 0000000..1d53530 --- /dev/null +++ b/src/compiler/nir/nir_lower_wpos_ytransform.c @@ -0,0 +1,310 @@ +/* + * 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 gl_FragCoord (and fddy) to account for driver's requested coordinate- + * origin and pixel-center vs. shader. If transformation is required, a + * gl_FbWposYTransform uniform is inserted (with the specified state-slots) + * and additional instructions are inserted to transform gl_FragCoord (and + * fddy src arg). + * + * This is based on the logic in emit_wpos()/emit_wpos_adjustment() in TGSI + * compiler. + * + * Run before nir_lower_io. + */ + +typedef struct { + const nir_lower_wpos_ytransform_options *options; + nir_shader *shader; + nir_builder b; + nir_variable *transform; +} lower_wpos_ytransform_state; + +static nir_ssa_def * +get_transform(lower_wpos_ytransform_state *state) +{ + if (state->transform == NULL) { + /* NOTE: name must be prefixed w/ "gl_" to trigger slot based + * special handling in uniform setup: + */ + nir_variable *var = nir_variable_create(state->shader, + nir_var_uniform, + glsl_vec4_type(), + "gl_FbWposYTransform"); + + var->num_state_slots = 1; + var->state_slots = ralloc_array(var, nir_state_slot, 1); + memcpy(var->state_slots[0].tokens, state->options->state_tokens, + sizeof(var->state_slots[0].tokens)); + + state->transform = var; + } + return nir_load_var(&state->b, state->transform); +} + +/* NIR equiv of TGSI CMP instruction: */ +static nir_ssa_def * +nir_cmp(nir_builder *b, nir_ssa_def *src0, nir_ssa_def *src1, nir_ssa_def *src2) +{ + return nir_bcsel(b, nir_flt(b, src0, nir_imm_float(b, 0.0)), src1, src2); +} + +/* see emit_wpos_adjustment() in st_mesa_to_tgsi.c */ +static void +emit_wpos_adjustment(lower_wpos_ytransform_state *state, + nir_intrinsic_instr *intr, + bool invert, float adjX, float adjY[2]) +{ + nir_builder *b = &state->b; + nir_variable *fragcoord = intr->variables[0]->var; + nir_ssa_def *wpostrans, *wpos_temp, *wpos_temp_y, *wpos_input; + + assert(intr->dest.is_ssa); + + b->cursor = nir_before_instr(&intr->instr); + + wpostrans = get_transform(state); + wpos_input = nir_load_var(b, fragcoord); + + /* First, apply the coordinate shift: */ + if (adjX || adjY[0] || adjY[1]) { + if (adjY[0] != adjY[1]) { + /* Adjust the y coordinate by adjY[1] or adjY[0] respectively + * depending on whether inversion is actually going to be applied + * or not, which is determined by testing against the inversion + * state variable used below, which will be either +1 or -1. + */ + nir_ssa_def *adj_temp; + + adj_temp = nir_cmp(b, + nir_channel(b, wpostrans, invert ? 2 : 0), + nir_imm_vec4(b, adjX, adjY[0], 0.0f, 0.0f), + nir_imm_vec4(b, adjX, adjY[1], 0.0f, 0.0f)); + + wpos_temp = nir_fadd(b, wpos_input, adj_temp); + } else { + wpos_temp = nir_fadd(b, + wpos_input, + nir_imm_vec4(b, adjX, adjY[0], 0.0f, 0.0f)); + } + wpos_input = wpos_temp; + } else { + /* MOV wpos_temp, input[wpos] + */ + wpos_temp = wpos_input; + } + + /* Now the conditional y flip: STATE_FB_WPOS_Y_TRANSFORM.xy/zw will be + * inversion/identity, or the other way around if we're drawing to an FBO. + */ + if (invert) { + /* MAD wpos_temp.y, wpos_input, wpostrans.xxxx, wpostrans.yyyy + */ + wpos_temp_y = nir_ffma(b, + nir_channel(b, wpos_temp, 1), + nir_channel(b, wpostrans, 0), + nir_channel(b, wpostrans, 1)); + } else { + /* MAD wpos_temp.y, wpos_input, wpostrans.zzzz, wpostrans.wwww + */ + wpos_temp_y = nir_ffma(b, + nir_channel(b, wpos_temp, 1), + nir_channel(b, wpostrans, 2), + nir_channel(b, wpostrans, 3)); + } + + wpos_temp = nir_vec4(b, + nir_channel(b, wpos_temp, 0), + wpos_temp_y, + nir_channel(b, wpos_temp, 2), + nir_channel(b, wpos_temp, 3)); + + nir_ssa_def_rewrite_uses(&intr->dest.ssa, nir_src_for_ssa(wpos_temp)); +} + +static void +lower_fragcoord(lower_wpos_ytransform_state *state, nir_intrinsic_instr *intr) +{ + const nir_lower_wpos_ytransform_options *options = state->options; + nir_variable *fragcoord = intr->variables[0]->var; + float adjX = 0.0f; + float adjY[2] = { 0.0f, 0.0f }; + bool invert = false; + + /* Based on logic in emit_wpos(): + * + * Query the pixel center conventions supported by the pipe driver and set + * adjX, adjY to help out if it cannot handle the requested one internally. + * + * The bias of the y-coordinate depends on whether y-inversion takes place + * (adjY[1]) or not (adjY[0]), which is in turn dependent on whether we are + * drawing to an FBO (causes additional inversion), and whether the the pipe + * driver origin and the requested origin differ (the latter condition is + * stored in the 'invert' variable). + * + * For height = 100 (i = integer, h = half-integer, l = lower, u = upper): + * + * center shift only: + * i -> h: +0.5 + * h -> i: -0.5 + * + * inversion only: + * l,i -> u,i: ( 0.0 + 1.0) * -1 + 100 = 99 + * l,h -> u,h: ( 0.5 + 0.0) * -1 + 100 = 99.5 + * u,i -> l,i: (99.0 + 1.0) * -1 + 100 = 0 + * u,h -> l,h: (99.5 + 0.0) * -1 + 100 = 0.5 + * + * inversion and center shift: + * l,i -> u,h: ( 0.0 + 0.5) * -1 + 100 = 99.5 + * l,h -> u,i: ( 0.5 + 0.5) * -1 + 100 = 99 + * u,i -> l,h: (99.0 + 0.5) * -1 + 100 = 0.5 + * u,h -> l,i: (99.5 + 0.5) * -1 + 100 = 0 + */ + + if (fragcoord->data.origin_upper_left) { + /* Fragment shader wants origin in upper-left */ + if (options->fs_coord_origin_upper_left) { + /* the driver supports upper-left origin */ + } else if (options->fs_coord_origin_lower_left) { + /* the driver supports lower-left origin, need to invert Y */ + invert = true; + } else { + unreachable("invalid options"); + } + } else { + /* Fragment shader wants origin in lower-left */ + if (options->fs_coord_origin_lower_left) { + /* the driver supports lower-left origin */ + } else if (options->fs_coord_origin_upper_left) { + /* the driver supports upper-left origin, need to invert Y */ + invert = true; + } else { + unreachable("invalid options"); + } + } + + if (fragcoord->data.pixel_center_integer) { + /* Fragment shader wants pixel center integer */ + if (options->fs_coord_pixel_center_integer) { + /* the driver supports pixel center integer */ + adjY[1] = 1.0f; + } else if (options->fs_coord_pixel_center_half_integer) { + /* the driver supports pixel center half integer, need to bias X,Y */ + adjX = -0.5f; + adjY[0] = -0.5f; + adjY[1] = 0.5f; + } else { + unreachable("invalid options"); + } + } else { + /* Fragment shader wants pixel center half integer */ + if (options->fs_coord_pixel_center_half_integer) { + /* the driver supports pixel center half integer */ + } else if (options->fs_coord_pixel_center_integer) { + /* the driver supports pixel center integer, need to bias X,Y */ + adjX = adjY[0] = adjY[1] = 0.5f; + } else { + unreachable("invalid options"); + } + } + + emit_wpos_adjustment(state, intr, invert, adjX, adjY); +} + +/* turns 'fddy(p)' into 'fddy(fmul(p, transform.x))' */ +static void +lower_fddy(lower_wpos_ytransform_state *state, nir_alu_instr *fddy) +{ + nir_builder *b = &state->b; + nir_ssa_def *p, *pt, *trans; + + b->cursor = nir_before_instr(&fddy->instr); + + p = nir_ssa_for_alu_src(b, fddy, 0); + trans = get_transform(state); + pt = nir_fmul(b, p, nir_channel(b, trans, 0)); + + nir_instr_rewrite_src(&fddy->instr, + &fddy->src[0].src, + nir_src_for_ssa(pt)); +} + +static bool +lower_wpos_ytransform_block(lower_wpos_ytransform_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 (strcmp(var->name, "gl_FragCoord") == 0) { + /* gl_FragCoord should not have array/struct deref's: */ + assert(dvar->deref.child == NULL); + lower_fragcoord(state, intr); + } + } + } else if (instr->type == nir_instr_type_alu) { + nir_alu_instr *alu = nir_instr_as_alu(instr); + if (alu->op == nir_op_fddy) + lower_fddy(state, alu); + } + } + + return true; +} + +static void +lower_wpos_ytransform_impl(lower_wpos_ytransform_state *state, nir_function_impl *impl) +{ + nir_builder_init(&state->b, impl); + + nir_foreach_block(block, impl) { + lower_wpos_ytransform_block(state, block); + } + nir_metadata_preserve(impl, nir_metadata_block_index | + nir_metadata_dominance); +} + +bool +nir_lower_wpos_ytransform(nir_shader *shader, + const nir_lower_wpos_ytransform_options *options) +{ + lower_wpos_ytransform_state state = { + .options = options, + .shader = shader, + }; + + assert(shader->stage == MESA_SHADER_FRAGMENT); + + nir_foreach_function(function, shader) { + if (function->impl) + lower_wpos_ytransform_impl(&state, function->impl); + } + + return state.transform != NULL; +} -- 2.5.5 </blockquote></div> </div></div>