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|
/**************************************************************************
*
* Copyright 2009 VMware, Inc.
* 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 VMWARE 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.
*
**************************************************************************/
/**
* @file
* Texture sampling -- common code.
*
* @author Jose Fonseca <jfonseca@vmware.com>
*/
#include "pipe/p_defines.h"
#include "pipe/p_state.h"
#include "util/u_format.h"
#include "util/u_math.h"
#include "lp_bld_arit.h"
#include "lp_bld_const.h"
#include "lp_bld_debug.h"
#include "lp_bld_printf.h"
#include "lp_bld_flow.h"
#include "lp_bld_sample.h"
#include "lp_bld_swizzle.h"
#include "lp_bld_type.h"
/*
* Bri-linear factor. Use zero or any other number less than one to force
* tri-linear filtering.
*/
#define BRILINEAR_FACTOR 2
/**
* Does the given texture wrap mode allow sampling the texture border color?
* XXX maybe move this into gallium util code.
*/
boolean
lp_sampler_wrap_mode_uses_border_color(unsigned mode,
unsigned min_img_filter,
unsigned mag_img_filter)
{
switch (mode) {
case PIPE_TEX_WRAP_REPEAT:
case PIPE_TEX_WRAP_CLAMP_TO_EDGE:
case PIPE_TEX_WRAP_MIRROR_REPEAT:
case PIPE_TEX_WRAP_MIRROR_CLAMP_TO_EDGE:
return FALSE;
case PIPE_TEX_WRAP_CLAMP:
case PIPE_TEX_WRAP_MIRROR_CLAMP:
if (min_img_filter == PIPE_TEX_FILTER_NEAREST &&
mag_img_filter == PIPE_TEX_FILTER_NEAREST) {
return FALSE;
} else {
return TRUE;
}
case PIPE_TEX_WRAP_CLAMP_TO_BORDER:
case PIPE_TEX_WRAP_MIRROR_CLAMP_TO_BORDER:
return TRUE;
default:
assert(0 && "unexpected wrap mode");
return FALSE;
}
}
/**
* Initialize lp_sampler_static_state object with the gallium sampler
* and texture state.
* The former is considered to be static and the later dynamic.
*/
void
lp_sampler_static_state(struct lp_sampler_static_state *state,
const struct pipe_sampler_view *view,
const struct pipe_sampler_state *sampler)
{
const struct pipe_resource *texture = view->texture;
memset(state, 0, sizeof *state);
if(!texture)
return;
if(!sampler)
return;
/*
* We don't copy sampler state over unless it is actually enabled, to avoid
* spurious recompiles, as the sampler static state is part of the shader
* key.
*
* Ideally the state tracker or cso_cache module would make all state
* canonical, but until that happens it's better to be safe than sorry here.
*
* XXX: Actually there's much more than can be done here, especially
* regarding 1D/2D/3D/CUBE textures, wrap modes, etc.
*/
state->format = view->format;
state->swizzle_r = view->swizzle_r;
state->swizzle_g = view->swizzle_g;
state->swizzle_b = view->swizzle_b;
state->swizzle_a = view->swizzle_a;
state->target = texture->target;
state->pot_width = util_is_power_of_two(texture->width0);
state->pot_height = util_is_power_of_two(texture->height0);
state->pot_depth = util_is_power_of_two(texture->depth0);
state->wrap_s = sampler->wrap_s;
state->wrap_t = sampler->wrap_t;
state->wrap_r = sampler->wrap_r;
state->min_img_filter = sampler->min_img_filter;
state->mag_img_filter = sampler->mag_img_filter;
if (view->last_level && sampler->max_lod > 0.0f) {
state->min_mip_filter = sampler->min_mip_filter;
} else {
state->min_mip_filter = PIPE_TEX_MIPFILTER_NONE;
}
if (state->min_mip_filter != PIPE_TEX_MIPFILTER_NONE) {
if (sampler->lod_bias != 0.0f) {
state->lod_bias_non_zero = 1;
}
/* If min_lod == max_lod we can greatly simplify mipmap selection.
* This is a case that occurs during automatic mipmap generation.
*/
if (sampler->min_lod == sampler->max_lod) {
state->min_max_lod_equal = 1;
} else {
if (sampler->min_lod > 0.0f) {
state->apply_min_lod = 1;
}
if (sampler->max_lod < (float)view->last_level) {
state->apply_max_lod = 1;
}
}
}
state->compare_mode = sampler->compare_mode;
if (sampler->compare_mode != PIPE_TEX_COMPARE_NONE) {
state->compare_func = sampler->compare_func;
}
state->normalized_coords = sampler->normalized_coords;
/*
* FIXME: Handle the remainder of pipe_sampler_view.
*/
}
/**
* Generate code to compute coordinate gradient (rho).
* \param ddx partial derivatives of (s, t, r, q) with respect to X
* \param ddy partial derivatives of (s, t, r, q) with respect to Y
*
* XXX: The resulting rho is scalar, so we ignore all but the first element of
* derivatives that are passed by the shader.
*/
static LLVMValueRef
lp_build_rho(struct lp_build_sample_context *bld,
const LLVMValueRef ddx[4],
const LLVMValueRef ddy[4])
{
struct lp_build_context *float_size_bld = &bld->float_size_bld;
struct lp_build_context *float_bld = &bld->float_bld;
const int dims = texture_dims(bld->static_state->target);
LLVMTypeRef i32t = LLVMInt32Type();
LLVMValueRef index0 = LLVMConstInt(i32t, 0, 0);
LLVMValueRef index1 = LLVMConstInt(i32t, 1, 0);
LLVMValueRef index2 = LLVMConstInt(i32t, 2, 0);
LLVMValueRef dsdx, dsdy, dtdx, dtdy, drdx, drdy;
LLVMValueRef rho_x, rho_y;
LLVMValueRef rho_vec;
LLVMValueRef float_size;
LLVMValueRef rho;
dsdx = LLVMBuildExtractElement(bld->builder, ddx[0], index0, "dsdx");
dsdy = LLVMBuildExtractElement(bld->builder, ddy[0], index0, "dsdy");
if (dims <= 1) {
rho_x = dsdx;
rho_y = dsdy;
}
else {
rho_x = float_size_bld->undef;
rho_y = float_size_bld->undef;
rho_x = LLVMBuildInsertElement(bld->builder, rho_x, dsdx, index0, "");
rho_y = LLVMBuildInsertElement(bld->builder, rho_y, dsdy, index0, "");
dtdx = LLVMBuildExtractElement(bld->builder, ddx[1], index0, "dtdx");
dtdy = LLVMBuildExtractElement(bld->builder, ddy[1], index0, "dtdy");
rho_x = LLVMBuildInsertElement(bld->builder, rho_x, dtdx, index1, "");
rho_y = LLVMBuildInsertElement(bld->builder, rho_y, dtdy, index1, "");
if (dims >= 3) {
drdx = LLVMBuildExtractElement(bld->builder, ddx[2], index0, "drdx");
drdy = LLVMBuildExtractElement(bld->builder, ddy[2], index0, "drdy");
rho_x = LLVMBuildInsertElement(bld->builder, rho_x, drdx, index2, "");
rho_y = LLVMBuildInsertElement(bld->builder, rho_y, drdy, index2, "");
}
}
rho_x = lp_build_abs(float_size_bld, rho_x);
rho_y = lp_build_abs(float_size_bld, rho_y);
rho_vec = lp_build_max(float_size_bld, rho_x, rho_y);
float_size = lp_build_int_to_float(float_size_bld, bld->uint_size);
rho_vec = lp_build_mul(float_size_bld, rho_vec, float_size);
if (dims <= 1) {
rho = rho_vec;
}
else {
if (dims >= 2) {
LLVMValueRef rho_s, rho_t, rho_r;
rho_s = LLVMBuildExtractElement(bld->builder, rho_vec, index0, "");
rho_t = LLVMBuildExtractElement(bld->builder, rho_vec, index1, "");
rho = lp_build_max(float_bld, rho_s, rho_t);
if (dims >= 3) {
rho_r = LLVMBuildExtractElement(bld->builder, rho_vec, index0, "");
rho = lp_build_max(float_bld, rho, rho_r);
}
}
}
return rho;
}
/*
* Bri-linear lod computation
*
* Use a piece-wise linear approximation of log2 such that:
* - round to nearest, for values in the neighborhood of -1, 0, 1, 2, etc.
* - linear approximation for values in the neighborhood of 0.5, 1.5., etc,
* with the steepness specified in 'factor'
* - exact result for 0.5, 1.5, etc.
*
*
* 1.0 - /----*
* /
* /
* /
* 0.5 - *
* /
* /
* /
* 0.0 - *----/
*
* | |
* 2^0 2^1
*
* This is a technique also commonly used in hardware:
* - http://ixbtlabs.com/articles2/gffx/nv40-rx800-3.html
*
* TODO: For correctness, this should only be applied when texture is known to
* have regular mipmaps, i.e., mipmaps derived from the base level.
*
* TODO: This could be done in fixed point, where applicable.
*/
static void
lp_build_brilinear_lod(struct lp_build_sample_context *bld,
LLVMValueRef lod,
double factor,
LLVMValueRef *out_lod_ipart,
LLVMValueRef *out_lod_fpart)
{
struct lp_build_context *float_bld = &bld->float_bld;
LLVMValueRef lod_fpart;
float pre_offset = (factor - 0.5)/factor - 0.5;
float post_offset = 1 - factor;
if (0) {
lp_build_printf(bld->builder, "lod = %f\n", lod);
}
lod = lp_build_add(float_bld, lod,
lp_build_const_vec(float_bld->type, pre_offset));
lp_build_ifloor_fract(float_bld, lod, out_lod_ipart, &lod_fpart);
lod_fpart = lp_build_mul(float_bld, lod_fpart,
lp_build_const_vec(float_bld->type, factor));
lod_fpart = lp_build_add(float_bld, lod_fpart,
lp_build_const_vec(float_bld->type, post_offset));
/*
* It's not necessary to clamp lod_fpart since:
* - the above expression will never produce numbers greater than one.
* - the mip filtering branch is only taken if lod_fpart is positive
*/
*out_lod_fpart = lod_fpart;
if (0) {
lp_build_printf(bld->builder, "lod_ipart = %i\n", *out_lod_ipart);
lp_build_printf(bld->builder, "lod_fpart = %f\n\n", *out_lod_fpart);
}
}
/**
* Generate code to compute texture level of detail (lambda).
* \param ddx partial derivatives of (s, t, r, q) with respect to X
* \param ddy partial derivatives of (s, t, r, q) with respect to Y
* \param lod_bias optional float vector with the shader lod bias
* \param explicit_lod optional float vector with the explicit lod
* \param width scalar int texture width
* \param height scalar int texture height
* \param depth scalar int texture depth
*
* XXX: The resulting lod is scalar, so ignore all but the first element of
* derivatives, lod_bias, etc that are passed by the shader.
*/
void
lp_build_lod_selector(struct lp_build_sample_context *bld,
unsigned unit,
const LLVMValueRef ddx[4],
const LLVMValueRef ddy[4],
LLVMValueRef lod_bias, /* optional */
LLVMValueRef explicit_lod, /* optional */
LLVMValueRef width,
LLVMValueRef height,
LLVMValueRef depth,
unsigned mip_filter,
LLVMValueRef *out_lod_ipart,
LLVMValueRef *out_lod_fpart)
{
struct lp_build_context *float_bld = &bld->float_bld;
LLVMValueRef lod;
*out_lod_ipart = bld->int_bld.zero;
*out_lod_fpart = bld->float_bld.zero;
if (bld->static_state->min_max_lod_equal) {
/* User is forcing sampling from a particular mipmap level.
* This is hit during mipmap generation.
*/
LLVMValueRef min_lod =
bld->dynamic_state->min_lod(bld->dynamic_state, bld->builder, unit);
lod = min_lod;
}
else {
LLVMValueRef sampler_lod_bias =
bld->dynamic_state->lod_bias(bld->dynamic_state, bld->builder, unit);
LLVMValueRef index0 = LLVMConstInt(LLVMInt32Type(), 0, 0);
if (explicit_lod) {
lod = LLVMBuildExtractElement(bld->builder, explicit_lod,
index0, "");
}
else {
LLVMValueRef rho;
rho = lp_build_rho(bld, ddx, ddy);
/* compute lod = log2(rho) */
if ((mip_filter == PIPE_TEX_MIPFILTER_NONE ||
mip_filter == PIPE_TEX_MIPFILTER_NEAREST) &&
!lod_bias &&
!bld->static_state->lod_bias_non_zero &&
!bld->static_state->apply_max_lod &&
!bld->static_state->apply_min_lod) {
*out_lod_ipart = lp_build_ilog2(float_bld, rho);
*out_lod_fpart = bld->float_bld.zero;
return;
}
if (0) {
lod = lp_build_log2(float_bld, rho);
}
else {
lod = lp_build_fast_log2(float_bld, rho);
}
/* add shader lod bias */
if (lod_bias) {
lod_bias = LLVMBuildExtractElement(bld->builder, lod_bias,
index0, "");
lod = LLVMBuildFAdd(bld->builder, lod, lod_bias, "shader_lod_bias");
}
}
/* add sampler lod bias */
if (bld->static_state->lod_bias_non_zero)
lod = LLVMBuildFAdd(bld->builder, lod, sampler_lod_bias, "sampler_lod_bias");
/* clamp lod */
if (bld->static_state->apply_max_lod) {
LLVMValueRef max_lod =
bld->dynamic_state->max_lod(bld->dynamic_state, bld->builder, unit);
lod = lp_build_min(float_bld, lod, max_lod);
}
if (bld->static_state->apply_min_lod) {
LLVMValueRef min_lod =
bld->dynamic_state->min_lod(bld->dynamic_state, bld->builder, unit);
lod = lp_build_max(float_bld, lod, min_lod);
}
}
if (mip_filter == PIPE_TEX_MIPFILTER_LINEAR) {
if (BRILINEAR_FACTOR > 1.0) {
lp_build_brilinear_lod(bld, lod, BRILINEAR_FACTOR,
out_lod_ipart, out_lod_fpart);
}
else {
lp_build_ifloor_fract(float_bld, lod, out_lod_ipart, out_lod_fpart);
}
lp_build_name(*out_lod_ipart, "lod_ipart");
lp_build_name(*out_lod_fpart, "lod_fpart");
}
else {
*out_lod_ipart = lp_build_iround(float_bld, lod);
}
return;
}
/**
* For PIPE_TEX_MIPFILTER_NEAREST, convert float LOD to integer
* mipmap level index.
* Note: this is all scalar code.
* \param lod scalar float texture level of detail
* \param level_out returns integer
*/
void
lp_build_nearest_mip_level(struct lp_build_sample_context *bld,
unsigned unit,
LLVMValueRef lod_ipart,
LLVMValueRef *level_out)
{
struct lp_build_context *int_bld = &bld->int_bld;
LLVMValueRef last_level, level;
LLVMValueRef zero = LLVMConstInt(LLVMInt32Type(), 0, 0);
last_level = bld->dynamic_state->last_level(bld->dynamic_state,
bld->builder, unit);
/* convert float lod to integer */
level = lod_ipart;
/* clamp level to legal range of levels */
*level_out = lp_build_clamp(int_bld, level, zero, last_level);
}
/**
* For PIPE_TEX_MIPFILTER_LINEAR, convert float LOD to integer to
* two (adjacent) mipmap level indexes. Later, we'll sample from those
* two mipmap levels and interpolate between them.
*/
void
lp_build_linear_mip_levels(struct lp_build_sample_context *bld,
unsigned unit,
LLVMValueRef lod_ipart,
LLVMValueRef *lod_fpart_inout,
LLVMValueRef *level0_out,
LLVMValueRef *level1_out)
{
LLVMBuilderRef builder = bld->builder;
struct lp_build_context *int_bld = &bld->int_bld;
struct lp_build_context *float_bld = &bld->float_bld;
LLVMValueRef last_level;
LLVMValueRef clamp_min;
LLVMValueRef clamp_max;
*level0_out = lod_ipart;
*level1_out = lp_build_add(int_bld, lod_ipart, int_bld->one);
last_level = bld->dynamic_state->last_level(bld->dynamic_state,
bld->builder, unit);
/*
* Clamp both lod_ipart and lod_ipart + 1 to [0, last_level], with the
* minimum number of comparisons, and zeroing lod_fpart in the extreme
* ends in the process.
*/
/* lod_ipart < 0 */
clamp_min = LLVMBuildICmp(builder, LLVMIntSLT,
lod_ipart, int_bld->zero,
"clamp_lod_to_zero");
*level0_out = LLVMBuildSelect(builder, clamp_min,
int_bld->zero, *level0_out, "");
*level1_out = LLVMBuildSelect(builder, clamp_min,
int_bld->zero, *level1_out, "");
*lod_fpart_inout = LLVMBuildSelect(builder, clamp_min,
float_bld->zero, *lod_fpart_inout, "");
/* lod_ipart >= last_level */
clamp_max = LLVMBuildICmp(builder, LLVMIntSGE,
lod_ipart, last_level,
"clamp_lod_to_last");
*level0_out = LLVMBuildSelect(builder, clamp_max,
last_level, *level0_out, "");
*level1_out = LLVMBuildSelect(builder, clamp_max,
last_level, *level1_out, "");
*lod_fpart_inout = LLVMBuildSelect(builder, clamp_max,
float_bld->zero, *lod_fpart_inout, "");
lp_build_name(*level0_out, "sampler%u_miplevel0", unit);
lp_build_name(*level1_out, "sampler%u_miplevel1", unit);
lp_build_name(*lod_fpart_inout, "sampler%u_mipweight", unit);
}
/**
* Return pointer to a single mipmap level.
* \param data_array array of pointers to mipmap levels
* \param level integer mipmap level
*/
LLVMValueRef
lp_build_get_mipmap_level(struct lp_build_sample_context *bld,
LLVMValueRef data_array, LLVMValueRef level)
{
LLVMValueRef indexes[2], data_ptr;
indexes[0] = LLVMConstInt(LLVMInt32Type(), 0, 0);
indexes[1] = level;
data_ptr = LLVMBuildGEP(bld->builder, data_array, indexes, 2, "");
data_ptr = LLVMBuildLoad(bld->builder, data_ptr, "");
return data_ptr;
}
LLVMValueRef
lp_build_get_const_mipmap_level(struct lp_build_sample_context *bld,
LLVMValueRef data_array, int level)
{
LLVMValueRef lvl = LLVMConstInt(LLVMInt32Type(), level, 0);
return lp_build_get_mipmap_level(bld, data_array, lvl);
}
/**
* Codegen equivalent for u_minify().
* Return max(1, base_size >> level);
*/
static LLVMValueRef
lp_build_minify(struct lp_build_sample_context *bld,
LLVMValueRef base_size,
LLVMValueRef level)
{
if (level == bld->int_coord_bld.zero) {
/* if we're using mipmap level zero, no minification is needed */
return base_size;
}
else {
LLVMValueRef size =
LLVMBuildLShr(bld->builder, base_size, level, "minify");
size = lp_build_max(&bld->int_coord_bld, size, bld->int_coord_bld.one);
return size;
}
}
/**
* Dereference stride_array[mipmap_level] array to get a stride.
* Return stride as a vector.
*/
static LLVMValueRef
lp_build_get_level_stride_vec(struct lp_build_sample_context *bld,
LLVMValueRef stride_array, LLVMValueRef level)
{
LLVMValueRef indexes[2], stride;
indexes[0] = LLVMConstInt(LLVMInt32Type(), 0, 0);
indexes[1] = level;
stride = LLVMBuildGEP(bld->builder, stride_array, indexes, 2, "");
stride = LLVMBuildLoad(bld->builder, stride, "");
stride = lp_build_broadcast_scalar(&bld->int_coord_bld, stride);
return stride;
}
/**
* When sampling a mipmap, we need to compute the width, height, depth
* of the source levels from the level indexes. This helper function
* does that.
*/
void
lp_build_mipmap_level_sizes(struct lp_build_sample_context *bld,
unsigned dims,
LLVMValueRef width_vec,
LLVMValueRef height_vec,
LLVMValueRef depth_vec,
LLVMValueRef ilevel,
LLVMValueRef row_stride_array,
LLVMValueRef img_stride_array,
LLVMValueRef *out_width_vec,
LLVMValueRef *out_height_vec,
LLVMValueRef *out_depth_vec,
LLVMValueRef *row_stride_vec,
LLVMValueRef *img_stride_vec)
{
LLVMValueRef ilevel_vec;
ilevel_vec = lp_build_broadcast_scalar(&bld->int_coord_bld, ilevel);
/*
* Compute width, height, depth at mipmap level 'ilevel'
*/
*out_width_vec = lp_build_minify(bld, width_vec, ilevel_vec);
if (dims >= 2) {
*out_height_vec = lp_build_minify(bld, height_vec, ilevel_vec);
*row_stride_vec = lp_build_get_level_stride_vec(bld,
row_stride_array,
ilevel);
if (dims == 3 || bld->static_state->target == PIPE_TEXTURE_CUBE) {
*img_stride_vec = lp_build_get_level_stride_vec(bld,
img_stride_array,
ilevel);
if (dims == 3) {
*out_depth_vec = lp_build_minify(bld, depth_vec, ilevel_vec);
}
}
}
}
/** Helper used by lp_build_cube_lookup() */
static LLVMValueRef
lp_build_cube_ima(struct lp_build_context *coord_bld, LLVMValueRef coord)
{
/* ima = -0.5 / abs(coord); */
LLVMValueRef negHalf = lp_build_const_vec(coord_bld->type, -0.5);
LLVMValueRef absCoord = lp_build_abs(coord_bld, coord);
LLVMValueRef ima = lp_build_div(coord_bld, negHalf, absCoord);
return ima;
}
/**
* Helper used by lp_build_cube_lookup()
* \param sign scalar +1 or -1
* \param coord float vector
* \param ima float vector
*/
static LLVMValueRef
lp_build_cube_coord(struct lp_build_context *coord_bld,
LLVMValueRef sign, int negate_coord,
LLVMValueRef coord, LLVMValueRef ima)
{
/* return negate(coord) * ima * sign + 0.5; */
LLVMValueRef half = lp_build_const_vec(coord_bld->type, 0.5);
LLVMValueRef res;
assert(negate_coord == +1 || negate_coord == -1);
if (negate_coord == -1) {
coord = lp_build_negate(coord_bld, coord);
}
res = lp_build_mul(coord_bld, coord, ima);
if (sign) {
sign = lp_build_broadcast_scalar(coord_bld, sign);
res = lp_build_mul(coord_bld, res, sign);
}
res = lp_build_add(coord_bld, res, half);
return res;
}
/** Helper used by lp_build_cube_lookup()
* Return (major_coord >= 0) ? pos_face : neg_face;
*/
static LLVMValueRef
lp_build_cube_face(struct lp_build_sample_context *bld,
LLVMValueRef major_coord,
unsigned pos_face, unsigned neg_face)
{
LLVMValueRef cmp = LLVMBuildFCmp(bld->builder, LLVMRealUGE,
major_coord,
bld->float_bld.zero, "");
LLVMValueRef pos = LLVMConstInt(LLVMInt32Type(), pos_face, 0);
LLVMValueRef neg = LLVMConstInt(LLVMInt32Type(), neg_face, 0);
LLVMValueRef res = LLVMBuildSelect(bld->builder, cmp, pos, neg, "");
return res;
}
/**
* Generate code to do cube face selection and compute per-face texcoords.
*/
void
lp_build_cube_lookup(struct lp_build_sample_context *bld,
LLVMValueRef s,
LLVMValueRef t,
LLVMValueRef r,
LLVMValueRef *face,
LLVMValueRef *face_s,
LLVMValueRef *face_t)
{
struct lp_build_context *float_bld = &bld->float_bld;
struct lp_build_context *coord_bld = &bld->coord_bld;
LLVMValueRef rx, ry, rz;
LLVMValueRef arx, ary, arz;
LLVMValueRef c25 = LLVMConstReal(LLVMFloatType(), 0.25);
LLVMValueRef arx_ge_ary, arx_ge_arz;
LLVMValueRef ary_ge_arx, ary_ge_arz;
LLVMValueRef arx_ge_ary_arz, ary_ge_arx_arz;
LLVMValueRef rx_pos, ry_pos, rz_pos;
assert(bld->coord_bld.type.length == 4);
/*
* Use the average of the four pixel's texcoords to choose the face.
*/
rx = lp_build_mul(float_bld, c25,
lp_build_sum_vector(&bld->coord_bld, s));
ry = lp_build_mul(float_bld, c25,
lp_build_sum_vector(&bld->coord_bld, t));
rz = lp_build_mul(float_bld, c25,
lp_build_sum_vector(&bld->coord_bld, r));
arx = lp_build_abs(float_bld, rx);
ary = lp_build_abs(float_bld, ry);
arz = lp_build_abs(float_bld, rz);
/*
* Compare sign/magnitude of rx,ry,rz to determine face
*/
arx_ge_ary = LLVMBuildFCmp(bld->builder, LLVMRealUGE, arx, ary, "");
arx_ge_arz = LLVMBuildFCmp(bld->builder, LLVMRealUGE, arx, arz, "");
ary_ge_arx = LLVMBuildFCmp(bld->builder, LLVMRealUGE, ary, arx, "");
ary_ge_arz = LLVMBuildFCmp(bld->builder, LLVMRealUGE, ary, arz, "");
arx_ge_ary_arz = LLVMBuildAnd(bld->builder, arx_ge_ary, arx_ge_arz, "");
ary_ge_arx_arz = LLVMBuildAnd(bld->builder, ary_ge_arx, ary_ge_arz, "");
rx_pos = LLVMBuildFCmp(bld->builder, LLVMRealUGE, rx, float_bld->zero, "");
ry_pos = LLVMBuildFCmp(bld->builder, LLVMRealUGE, ry, float_bld->zero, "");
rz_pos = LLVMBuildFCmp(bld->builder, LLVMRealUGE, rz, float_bld->zero, "");
{
struct lp_build_flow_context *flow_ctx;
struct lp_build_if_state if_ctx;
flow_ctx = lp_build_flow_create(bld->builder);
lp_build_flow_scope_begin(flow_ctx);
*face_s = bld->coord_bld.undef;
*face_t = bld->coord_bld.undef;
*face = bld->int_bld.undef;
lp_build_name(*face_s, "face_s");
lp_build_name(*face_t, "face_t");
lp_build_name(*face, "face");
lp_build_flow_scope_declare(flow_ctx, face_s);
lp_build_flow_scope_declare(flow_ctx, face_t);
lp_build_flow_scope_declare(flow_ctx, face);
lp_build_if(&if_ctx, flow_ctx, bld->builder, arx_ge_ary_arz);
{
/* +/- X face */
LLVMValueRef sign = lp_build_sgn(float_bld, rx);
LLVMValueRef ima = lp_build_cube_ima(coord_bld, s);
*face_s = lp_build_cube_coord(coord_bld, sign, +1, r, ima);
*face_t = lp_build_cube_coord(coord_bld, NULL, +1, t, ima);
*face = lp_build_cube_face(bld, rx,
PIPE_TEX_FACE_POS_X,
PIPE_TEX_FACE_NEG_X);
}
lp_build_else(&if_ctx);
{
struct lp_build_flow_context *flow_ctx2;
struct lp_build_if_state if_ctx2;
LLVMValueRef face_s2 = bld->coord_bld.undef;
LLVMValueRef face_t2 = bld->coord_bld.undef;
LLVMValueRef face2 = bld->int_bld.undef;
flow_ctx2 = lp_build_flow_create(bld->builder);
lp_build_flow_scope_begin(flow_ctx2);
lp_build_flow_scope_declare(flow_ctx2, &face_s2);
lp_build_flow_scope_declare(flow_ctx2, &face_t2);
lp_build_flow_scope_declare(flow_ctx2, &face2);
ary_ge_arx_arz = LLVMBuildAnd(bld->builder, ary_ge_arx, ary_ge_arz, "");
lp_build_if(&if_ctx2, flow_ctx2, bld->builder, ary_ge_arx_arz);
{
/* +/- Y face */
LLVMValueRef sign = lp_build_sgn(float_bld, ry);
LLVMValueRef ima = lp_build_cube_ima(coord_bld, t);
face_s2 = lp_build_cube_coord(coord_bld, NULL, -1, s, ima);
face_t2 = lp_build_cube_coord(coord_bld, sign, -1, r, ima);
face2 = lp_build_cube_face(bld, ry,
PIPE_TEX_FACE_POS_Y,
PIPE_TEX_FACE_NEG_Y);
}
lp_build_else(&if_ctx2);
{
/* +/- Z face */
LLVMValueRef sign = lp_build_sgn(float_bld, rz);
LLVMValueRef ima = lp_build_cube_ima(coord_bld, r);
face_s2 = lp_build_cube_coord(coord_bld, sign, -1, s, ima);
face_t2 = lp_build_cube_coord(coord_bld, NULL, +1, t, ima);
face2 = lp_build_cube_face(bld, rz,
PIPE_TEX_FACE_POS_Z,
PIPE_TEX_FACE_NEG_Z);
}
lp_build_endif(&if_ctx2);
lp_build_flow_scope_end(flow_ctx2);
lp_build_flow_destroy(flow_ctx2);
*face_s = face_s2;
*face_t = face_t2;
*face = face2;
}
lp_build_endif(&if_ctx);
lp_build_flow_scope_end(flow_ctx);
lp_build_flow_destroy(flow_ctx);
}
}
/**
* Compute the partial offset of a pixel block along an arbitrary axis.
*
* @param coord coordinate in pixels
* @param stride number of bytes between rows of successive pixel blocks
* @param block_length number of pixels in a pixels block along the coordinate
* axis
* @param out_offset resulting relative offset of the pixel block in bytes
* @param out_subcoord resulting sub-block pixel coordinate
*/
void
lp_build_sample_partial_offset(struct lp_build_context *bld,
unsigned block_length,
LLVMValueRef coord,
LLVMValueRef stride,
LLVMValueRef *out_offset,
LLVMValueRef *out_subcoord)
{
LLVMValueRef offset;
LLVMValueRef subcoord;
if (block_length == 1) {
subcoord = bld->zero;
}
else {
/*
* Pixel blocks have power of two dimensions. LLVM should convert the
* rem/div to bit arithmetic.
* TODO: Verify this.
* It does indeed BUT it does transform it to scalar (and back) when doing so
* (using roughly extract, shift/and, mov, unpack) (llvm 2.7).
* The generated code looks seriously unfunny and is quite expensive.
*/
#if 0
LLVMValueRef block_width = lp_build_const_int_vec(bld->type, block_length);
subcoord = LLVMBuildURem(bld->builder, coord, block_width, "");
coord = LLVMBuildUDiv(bld->builder, coord, block_width, "");
#else
unsigned logbase2 = util_unsigned_logbase2(block_length);
LLVMValueRef block_shift = lp_build_const_int_vec(bld->type, logbase2);
LLVMValueRef block_mask = lp_build_const_int_vec(bld->type, block_length - 1);
subcoord = LLVMBuildAnd(bld->builder, coord, block_mask, "");
coord = LLVMBuildLShr(bld->builder, coord, block_shift, "");
#endif
}
offset = lp_build_mul(bld, coord, stride);
assert(out_offset);
assert(out_subcoord);
*out_offset = offset;
*out_subcoord = subcoord;
}
/**
* Compute the offset of a pixel block.
*
* x, y, z, y_stride, z_stride are vectors, and they refer to pixels.
*
* Returns the relative offset and i,j sub-block coordinates
*/
void
lp_build_sample_offset(struct lp_build_context *bld,
const struct util_format_description *format_desc,
LLVMValueRef x,
LLVMValueRef y,
LLVMValueRef z,
LLVMValueRef y_stride,
LLVMValueRef z_stride,
LLVMValueRef *out_offset,
LLVMValueRef *out_i,
LLVMValueRef *out_j)
{
LLVMValueRef x_stride;
LLVMValueRef offset;
x_stride = lp_build_const_vec(bld->type, format_desc->block.bits/8);
lp_build_sample_partial_offset(bld,
format_desc->block.width,
x, x_stride,
&offset, out_i);
if (y && y_stride) {
LLVMValueRef y_offset;
lp_build_sample_partial_offset(bld,
format_desc->block.height,
y, y_stride,
&y_offset, out_j);
offset = lp_build_add(bld, offset, y_offset);
}
else {
*out_j = bld->zero;
}
if (z && z_stride) {
LLVMValueRef z_offset;
LLVMValueRef k;
lp_build_sample_partial_offset(bld,
1, /* pixel blocks are always 2D */
z, z_stride,
&z_offset, &k);
offset = lp_build_add(bld, offset, z_offset);
}
*out_offset = offset;
}
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