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/**************************************************************************
*
* Copyright 2007 Tungsten Graphics, Inc., Cedar Park, Texas.
* 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 TUNGSTEN GRAPHICS 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.
*
**************************************************************************/
/**
* Texture sampling
*
* Authors:
* Brian Paul
*/
#include "main/macros.h"
#include "sp_context.h"
#include "sp_surface.h"
#include "sp_tex_sample.h"
#include "pipe/p_context.h"
#include "pipe/p_defines.h"
#include "pipe/tgsi/core/tgsi_exec.h"
/*
* Note, the FRAC macro has to work perfectly. Otherwise you'll sometimes
* see 1-pixel bands of improperly weighted linear-filtered textures.
* The tests/texwrap.c demo is a good test.
* Also note, FRAC(x) doesn't truly return the fractional part of x for x < 0.
* Instead, if x < 0 then FRAC(x) = 1 - true_frac(x).
*/
#define FRAC(f) ((f) - IFLOOR(f))
/**
* Linear interpolation macro
*/
#define LERP(T, A, B) ( (A) + (T) * ((B) - (A)) )
/**
* Do 2D/biliner interpolation of float values.
* v00, v10, v01 and v11 are typically four texture samples in a square/box.
* a and b are the horizontal and vertical interpolants.
* It's important that this function is inlined when compiled with
* optimization! If we find that's not true on some systems, convert
* to a macro.
*/
static INLINE GLfloat
lerp_2d(GLfloat a, GLfloat b,
GLfloat v00, GLfloat v10, GLfloat v01, GLfloat v11)
{
const GLfloat temp0 = LERP(a, v00, v10);
const GLfloat temp1 = LERP(a, v01, v11);
return LERP(b, temp0, temp1);
}
/**
* Compute the remainder of a divided by b, but be careful with
* negative values so that REPEAT mode works right.
*/
static INLINE GLint
repeat_remainder(GLint a, GLint b)
{
if (a >= 0)
return a % b;
else
return (a + 1) % b + b - 1;
}
/**
* Apply texture coord wrapping mode and return integer texture index.
* \param wrapMode PIPE_TEX_WRAP_x
* \param s the texcoord
* \param size the texture image size
* \return integer texture index
*/
static INLINE GLint
nearest_texcoord(GLuint wrapMode, GLfloat s, GLuint size)
{
GLint i;
switch (wrapMode) {
case PIPE_TEX_WRAP_REPEAT:
/* s limited to [0,1) */
/* i limited to [0,size-1] */
i = IFLOOR(s * size);
i = repeat_remainder(i, size);
return i;
case PIPE_TEX_WRAP_CLAMP:
/* s limited to [0,1] */
/* i limited to [0,size-1] */
if (s <= 0.0F)
i = 0;
else if (s >= 1.0F)
i = size - 1;
else
i = IFLOOR(s * size);
return i;
case PIPE_TEX_WRAP_CLAMP_TO_EDGE:
{
/* s limited to [min,max] */
/* i limited to [0, size-1] */
const GLfloat min = 1.0F / (2.0F * size);
const GLfloat max = 1.0F - min;
if (s < min)
i = 0;
else if (s > max)
i = size - 1;
else
i = IFLOOR(s * size);
}
return i;
case PIPE_TEX_WRAP_CLAMP_TO_BORDER:
{
/* s limited to [min,max] */
/* i limited to [-1, size] */
const GLfloat min = -1.0F / (2.0F * size);
const GLfloat max = 1.0F - min;
if (s <= min)
i = -1;
else if (s >= max)
i = size;
else
i = IFLOOR(s * size);
}
return i;
case PIPE_TEX_WRAP_MIRROR_REPEAT:
{
const GLfloat min = 1.0F / (2.0F * size);
const GLfloat max = 1.0F - min;
const GLint flr = IFLOOR(s);
GLfloat u;
if (flr & 1)
u = 1.0F - (s - (GLfloat) flr);
else
u = s - (GLfloat) flr;
if (u < min)
i = 0;
else if (u > max)
i = size - 1;
else
i = IFLOOR(u * size);
}
return i;
case PIPE_TEX_WRAP_MIRROR_CLAMP:
{
/* s limited to [0,1] */
/* i limited to [0,size-1] */
const GLfloat u = FABSF(s);
if (u <= 0.0F)
i = 0;
else if (u >= 1.0F)
i = size - 1;
else
i = IFLOOR(u * size);
}
return i;
case PIPE_TEX_WRAP_MIRROR_CLAMP_TO_EDGE:
{
/* s limited to [min,max] */
/* i limited to [0, size-1] */
const GLfloat min = 1.0F / (2.0F * size);
const GLfloat max = 1.0F - min;
const GLfloat u = FABSF(s);
if (u < min)
i = 0;
else if (u > max)
i = size - 1;
else
i = IFLOOR(u * size);
}
return i;
case PIPE_TEX_WRAP_MIRROR_CLAMP_TO_BORDER:
{
/* s limited to [min,max] */
/* i limited to [0, size-1] */
const GLfloat min = -1.0F / (2.0F * size);
const GLfloat max = 1.0F - min;
const GLfloat u = FABSF(s);
if (u < min)
i = -1;
else if (u > max)
i = size;
else
i = IFLOOR(u * size);
}
return i;
default:
assert(0);
return 0;
}
}
/**
* Used to compute texel locations for linear sampling.
* \param wrapMode PIPE_TEX_WRAP_x
* \param s the texcoord
* \param size the texture image size
* \param i0 returns first texture index
* \param i1 returns second texture index (usually *i0 + 1)
* \param a returns blend factor/weight between texture indexes
*/
static INLINE void
linear_texcoord(GLuint wrapMode, GLfloat s, GLuint size,
GLint *i0, GLint *i1, GLfloat *a)
{
GLfloat u;
switch (wrapMode) {
case PIPE_TEX_WRAP_REPEAT:
u = s * size - 0.5F;
*i0 = repeat_remainder(IFLOOR(u), size);
*i1 = repeat_remainder(*i0 + 1, size);
break;
case PIPE_TEX_WRAP_CLAMP:
if (s <= 0.0F)
u = 0.0F;
else if (s >= 1.0F)
u = (GLfloat) size;
else
u = s * size;
u -= 0.5F;
*i0 = IFLOOR(u);
*i1 = *i0 + 1;
break;
case PIPE_TEX_WRAP_CLAMP_TO_EDGE:
if (s <= 0.0F)
u = 0.0F;
else if (s >= 1.0F)
u = (GLfloat) size;
else
u = s * size;
u -= 0.5F;
*i0 = IFLOOR(u);
*i1 = *i0 + 1;
if (*i0 < 0)
*i0 = 0;
if (*i1 >= (GLint) size)
*i1 = size - 1;
break;
case PIPE_TEX_WRAP_CLAMP_TO_BORDER:
{
const GLfloat min = -1.0F / (2.0F * size);
const GLfloat max = 1.0F - min;
if (s <= min)
u = min * size;
else if (s >= max)
u = max * size;
else
u = s * size;
u -= 0.5F;
*i0 = IFLOOR(u);
*i1 = *i0 + 1;
}
break;
case PIPE_TEX_WRAP_MIRROR_REPEAT:
{
const GLint flr = IFLOOR(s);
if (flr & 1)
u = 1.0F - (s - (GLfloat) flr);
else
u = s - (GLfloat) flr;
u = (u * size) - 0.5F;
*i0 = IFLOOR(u);
*i1 = *i0 + 1;
if (*i0 < 0)
*i0 = 0;
if (*i1 >= (GLint) size)
*i1 = size - 1;
}
break;
case PIPE_TEX_WRAP_MIRROR_CLAMP:
u = FABSF(s);
if (u >= 1.0F)
u = (GLfloat) size;
else
u *= size;
u -= 0.5F;
*i0 = IFLOOR(u);
*i1 = *i0 + 1;
break;
case PIPE_TEX_WRAP_MIRROR_CLAMP_TO_EDGE:
u = FABSF(s);
if (u >= 1.0F)
u = (GLfloat) size;
else
u *= size;
u -= 0.5F;
*i0 = IFLOOR(u);
*i1 = *i0 + 1;
if (*i0 < 0)
*i0 = 0;
if (*i1 >= (GLint) size)
*i1 = size - 1;
break;
case PIPE_TEX_WRAP_MIRROR_CLAMP_TO_BORDER:
{
const GLfloat min = -1.0F / (2.0F * size);
const GLfloat max = 1.0F - min;
u = FABSF(s);
if (u <= min)
u = min * size;
else if (u >= max)
u = max * size;
else
u *= size;
u -= 0.5F;
*i0 = IFLOOR(u);
*i1 = *i0 + 1;
}
break;
default:
assert(0);
}
*a = FRAC(u);
}
static GLuint
choose_cube_face(const GLfloat texcoord[4], GLfloat newCoord[4])
{
/*
major axis
direction target sc tc ma
---------- ------------------------------- --- --- ---
+rx TEXTURE_CUBE_MAP_POSITIVE_X_EXT -rz -ry rx
-rx TEXTURE_CUBE_MAP_NEGATIVE_X_EXT +rz -ry rx
+ry TEXTURE_CUBE_MAP_POSITIVE_Y_EXT +rx +rz ry
-ry TEXTURE_CUBE_MAP_NEGATIVE_Y_EXT +rx -rz ry
+rz TEXTURE_CUBE_MAP_POSITIVE_Z_EXT +rx -ry rz
-rz TEXTURE_CUBE_MAP_NEGATIVE_Z_EXT -rx -ry rz
*/
const GLfloat rx = texcoord[0];
const GLfloat ry = texcoord[1];
const GLfloat rz = texcoord[2];
const GLfloat arx = FABSF(rx), ary = FABSF(ry), arz = FABSF(rz);
GLuint face;
GLfloat sc, tc, ma;
if (arx > ary && arx > arz) {
if (rx >= 0.0F) {
face = PIPE_TEX_FACE_POS_X;
sc = -rz;
tc = -ry;
ma = arx;
}
else {
face = PIPE_TEX_FACE_NEG_X;
sc = rz;
tc = -ry;
ma = arx;
}
}
else if (ary > arx && ary > arz) {
if (ry >= 0.0F) {
face = PIPE_TEX_FACE_POS_Y;
sc = rx;
tc = rz;
ma = ary;
}
else {
face = PIPE_TEX_FACE_NEG_Y;
sc = rx;
tc = -rz;
ma = ary;
}
}
else {
if (rz > 0.0F) {
face = PIPE_TEX_FACE_POS_Z;
sc = rx;
tc = -ry;
ma = arz;
}
else {
face = PIPE_TEX_FACE_NEG_Z;
sc = -rx;
tc = -ry;
ma = arz;
}
}
newCoord[0] = ( sc / ma + 1.0F ) * 0.5F;
newCoord[1] = ( tc / ma + 1.0F ) * 0.5F;
return face;
}
static void
sp_get_sample_1d(struct tgsi_sampler *sampler,
const GLfloat strq[4], GLfloat lambda, GLfloat rgba[4])
{
struct pipe_context *pipe = (struct pipe_context *) sampler->pipe;
struct pipe_surface *ps
= pipe->get_tex_surface(pipe, sampler->texture, 0, 0, 0);
switch (sampler->state->min_filter) {
case PIPE_TEX_FILTER_NEAREST:
{
GLint x;
x = nearest_texcoord(sampler->state->wrap_s, strq[0],
sampler->texture->width0);
ps->get_tile(ps, x, 0, 1, 1, rgba);
}
break;
case PIPE_TEX_FILTER_LINEAR:
{
GLfloat t0[4], t1[4];
GLint x0, x1;
GLfloat a;
linear_texcoord(sampler->state->wrap_s, strq[0],
sampler->texture->width0, &x0, &x1, &a);
ps->get_tile(ps, x0, 0, 1, 1, t0);
ps->get_tile(ps, x1, 0, 1, 1, t1);
rgba[0] = LERP(a, t0[0], t1[0]);
rgba[1] = LERP(a, t0[1], t1[1]);
rgba[2] = LERP(a, t0[2], t1[2]);
rgba[3] = LERP(a, t0[3], t1[3]);
}
break;
default:
assert(0);
}
}
static GLuint
choose_mipmap_level(struct tgsi_sampler *sampler, GLfloat lambda)
{
if (sampler->state->min_filter == sampler->state->mag_filter) {
assert(sampler->state->min_filter == PIPE_TEX_FILTER_LINEAR ||
sampler->state->min_filter == PIPE_TEX_FILTER_NEAREST);
return 0;
}
else {
GLint level = (int) lambda;
level = CLAMP(level, sampler->texture->first_level,
sampler->texture->last_level);
return level;
}
}
/**
* Called via tgsi_sampler::get_sample()
* Use the sampler's state setting to get a filtered RGBA value
* from the sampler's texture (mipmap tree).
*
* XXX we can implement many versions of this function, each
* tightly coded for a specific combination of sampler state
* (nearest + repeat), (bilinear mipmap + clamp), etc.
*
* The update_samplers() function in st_atom_sampler.c could create
* a new tgsi_sampler object for each state combo it finds....
*/
static void
sp_get_sample_2d(struct tgsi_sampler *sampler,
const GLfloat strq[4], GLfloat lambda, GLfloat rgba[4])
{
struct pipe_context *pipe = (struct pipe_context *) sampler->pipe;
GLuint filter;
GLint level0;
if (lambda < 0.0)
filter = sampler->state->mag_filter;
else
filter = sampler->state->min_filter;
level0 = choose_mipmap_level(sampler, lambda);
switch (filter) {
case PIPE_TEX_FILTER_NEAREST:
case PIPE_TEX_FILTER_NEAREST_MIPMAP_NEAREST:
{
GLint x = nearest_texcoord(sampler->state->wrap_s, strq[0],
sampler->texture->level[level0].width);
GLint y = nearest_texcoord(sampler->state->wrap_t, strq[1],
sampler->texture->level[level0].height);
GLint cx = x / SAMPLER_CACHE_SIZE;
GLint cy = y / SAMPLER_CACHE_SIZE;
if (cx != sampler->cache_x || cy != sampler->cache_y ||
level0 != sampler->cache_level) {
/* cache miss, replace cache with new tile */
struct pipe_surface *ps
= pipe->get_tex_surface(pipe, sampler->texture, 0, level0, 0);
assert(ps->width == sampler->texture->level[level0].width);
assert(ps->height == sampler->texture->level[level0].height);
sampler->cache_level = level0;
sampler->cache_x = cx;
sampler->cache_y = cy;
ps->get_tile(ps,
cx * SAMPLER_CACHE_SIZE,
cy * SAMPLER_CACHE_SIZE,
SAMPLER_CACHE_SIZE, SAMPLER_CACHE_SIZE,
(GLfloat *) sampler->cache);
/*printf("cache miss (%d, %d)\n", x, y);*/
}
else {
/*printf("cache hit (%d, %d)\n", x, y);*/
}
/* get texel from cache */
cx = x % SAMPLER_CACHE_SIZE;
cy = y % SAMPLER_CACHE_SIZE;
COPY_4V(rgba, sampler->cache[cy][cx]);
}
break;
case PIPE_TEX_FILTER_LINEAR:
{
GLfloat t00[4], t01[4], t10[4], t11[4];
GLint x0, y0, x1, y1;
GLfloat a, b;
struct pipe_surface *ps
= pipe->get_tex_surface(pipe, sampler->texture, 0, level0, 0);
linear_texcoord(sampler->state->wrap_s, strq[0],
sampler->texture->width0, &x0, &x1, &a);
linear_texcoord(sampler->state->wrap_t, strq[1],
sampler->texture->height0, &y0, &y1, &b);
ps->get_tile(ps, x0, y0, 1, 1, t00);
ps->get_tile(ps, x1, y0, 1, 1, t10);
ps->get_tile(ps, x0, y1, 1, 1, t01);
ps->get_tile(ps, x1, y1, 1, 1, t11);
rgba[0] = lerp_2d(a, b, t00[0], t10[0], t01[0], t11[0]);
rgba[1] = lerp_2d(a, b, t00[1], t10[1], t01[1], t11[1]);
rgba[2] = lerp_2d(a, b, t00[2], t10[2], t01[2], t11[2]);
rgba[3] = lerp_2d(a, b, t00[3], t10[3], t01[3], t11[3]);
}
break;
/*
{
GLuint level0, level1;
level0 = choose_mipmap_level(sampler, lambda);
}
break;
*/
default:
assert(0);
}
}
static void
sp_get_sample_3d(struct tgsi_sampler *sampler,
const GLfloat strq[4], GLfloat lamba, GLfloat rgba[4])
{
/* get/map pipe_surfaces corresponding to 3D tex slices */
}
static void
sp_get_sample_cube(struct tgsi_sampler *sampler,
const GLfloat strq[4], GLfloat lambda, GLfloat rgba[4])
{
GLfloat st[4];
GLuint face = choose_cube_face(strq, st);
/* get/map surface corresponding to the face */
}
void
sp_get_sample(struct tgsi_sampler *sampler,
const GLfloat strq[4], GLfloat lambda, GLfloat rgba[4])
{
switch (sampler->texture->target) {
case GL_TEXTURE_1D:
sp_get_sample_1d(sampler, strq, lambda, rgba);
break;
case GL_TEXTURE_2D:
sp_get_sample_2d(sampler, strq, lambda, rgba);
break;
case GL_TEXTURE_3D:
sp_get_sample_3d(sampler, strq, lambda, rgba);
break;
case GL_TEXTURE_CUBE_MAP:
sp_get_sample_cube(sampler, strq, lambda, rgba);
break;
default:
assert(0);
}
}
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