diff options
Diffstat (limited to 'src/gallium/drivers/softpipe/sp_tex_sample.c')
-rw-r--r-- | src/gallium/drivers/softpipe/sp_tex_sample.c | 916 |
1 files changed, 916 insertions, 0 deletions
diff --git a/src/gallium/drivers/softpipe/sp_tex_sample.c b/src/gallium/drivers/softpipe/sp_tex_sample.c new file mode 100644 index 0000000..325bdb8 --- /dev/null +++ b/src/gallium/drivers/softpipe/sp_tex_sample.c @@ -0,0 +1,916 @@ +/************************************************************************** + * + * 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 "sp_context.h" +#include "sp_headers.h" +#include "sp_surface.h" +#include "sp_tex_sample.h" +#include "sp_tile_cache.h" +#include "pipe/p_context.h" +#include "pipe/p_defines.h" +#include "pipe/p_util.h" +#include "pipe/tgsi/exec/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 float +lerp_2d(float a, float b, + float v00, float v10, float v01, float v11) +{ + const float temp0 = LERP(a, v00, v10); + const float temp1 = LERP(a, v01, v11); + return LERP(b, temp0, temp1); +} + + +/** + * If A is a signed integer, A % B doesn't give the right value for A < 0 + * (in terms of texture repeat). Just casting to unsigned fixes that. + */ +#define REMAINDER(A, B) ((unsigned) (A) % (unsigned) (B)) + + +/** + * 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 int +nearest_texcoord(unsigned wrapMode, float s, unsigned size) +{ + int i; + switch (wrapMode) { + case PIPE_TEX_WRAP_REPEAT: + /* s limited to [0,1) */ + /* i limited to [0,size-1] */ + i = ifloor(s * size); + i = 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 float min = 1.0F / (2.0F * size); + const float 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 float min = -1.0F / (2.0F * size); + const float 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 float min = 1.0F / (2.0F * size); + const float max = 1.0F - min; + const int flr = ifloor(s); + float u; + if (flr & 1) + u = 1.0F - (s - (float) flr); + else + u = s - (float) 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 float 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 float min = 1.0F / (2.0F * size); + const float max = 1.0F - min; + const float 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 float min = -1.0F / (2.0F * size); + const float max = 1.0F - min; + const float 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(unsigned wrapMode, float s, unsigned size, + int *i0, int *i1, float *a) +{ + float u; + switch (wrapMode) { + case PIPE_TEX_WRAP_REPEAT: + u = s * size - 0.5F; + *i0 = REMAINDER(ifloor(u), size); + *i1 = REMAINDER(*i0 + 1, size); + break; + case PIPE_TEX_WRAP_CLAMP: + if (s <= 0.0F) + u = 0.0F; + else if (s >= 1.0F) + u = (float) 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 = (float) size; + else + u = s * size; + u -= 0.5F; + *i0 = ifloor(u); + *i1 = *i0 + 1; + if (*i0 < 0) + *i0 = 0; + if (*i1 >= (int) size) + *i1 = size - 1; + break; + case PIPE_TEX_WRAP_CLAMP_TO_BORDER: + { + const float min = -1.0F / (2.0F * size); + const float 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 int flr = ifloor(s); + if (flr & 1) + u = 1.0F - (s - (float) flr); + else + u = s - (float) flr; + u = (u * size) - 0.5F; + *i0 = ifloor(u); + *i1 = *i0 + 1; + if (*i0 < 0) + *i0 = 0; + if (*i1 >= (int) size) + *i1 = size - 1; + } + break; + case PIPE_TEX_WRAP_MIRROR_CLAMP: + u = FABSF(s); + if (u >= 1.0F) + u = (float) 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 = (float) size; + else + u *= size; + u -= 0.5F; + *i0 = ifloor(u); + *i1 = *i0 + 1; + if (*i0 < 0) + *i0 = 0; + if (*i1 >= (int) size) + *i1 = size - 1; + break; + case PIPE_TEX_WRAP_MIRROR_CLAMP_TO_BORDER: + { + const float min = -1.0F / (2.0F * size); + const float 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 unsigned +choose_cube_face(float rx, float ry, float rz, float *newS, float *newT) +{ + /* + 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 float arx = FABSF(rx), ary = FABSF(ry), arz = FABSF(rz); + unsigned face; + float 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; + } + } + + *newS = ( sc / ma + 1.0F ) * 0.5F; + *newT = ( tc / ma + 1.0F ) * 0.5F; + + return face; +} + + +/** + * Examine the quad's texture coordinates to compute the partial + * derivatives w.r.t X and Y, then compute lambda (level of detail). + * + * This is only done for fragment shaders, not vertex shaders. + */ +static float +compute_lambda(struct tgsi_sampler *sampler, + const float s[QUAD_SIZE], + const float t[QUAD_SIZE], + const float p[QUAD_SIZE], + float lodbias) +{ + float rho, lambda; + + assert(s); + { + float dsdx = s[QUAD_BOTTOM_RIGHT] - s[QUAD_BOTTOM_LEFT]; + float dsdy = s[QUAD_TOP_LEFT] - s[QUAD_BOTTOM_LEFT]; + dsdx = FABSF(dsdx); + dsdy = FABSF(dsdy); + rho = MAX2(dsdx, dsdy); + if (sampler->state->normalized_coords) + rho *= sampler->texture->width[0]; + } + if (t) { + float dtdx = t[QUAD_BOTTOM_RIGHT] - t[QUAD_BOTTOM_LEFT]; + float dtdy = t[QUAD_TOP_LEFT] - t[QUAD_BOTTOM_LEFT]; + float max; + dtdx = FABSF(dtdx); + dtdy = FABSF(dtdy); + max = MAX2(dtdx, dtdy); + if (sampler->state->normalized_coords) + max *= sampler->texture->height[0]; + rho = MAX2(rho, max); + } + if (p) { + float dpdx = p[QUAD_BOTTOM_RIGHT] - p[QUAD_BOTTOM_LEFT]; + float dpdy = p[QUAD_TOP_LEFT] - p[QUAD_BOTTOM_LEFT]; + float max; + dpdx = FABSF(dpdx); + dpdy = FABSF(dpdy); + max = MAX2(dpdx, dpdy); + if (sampler->state->normalized_coords) + max *= sampler->texture->depth[0]; + rho = MAX2(rho, max); + } + + lambda = LOG2(rho); + lambda += lodbias + sampler->state->lod_bias; + lambda = CLAMP(lambda, sampler->state->min_lod, sampler->state->max_lod); + + return lambda; +} + + +/** + * Do several things here: + * 1. Compute lambda from the texcoords, if needed + * 2. Determine if we're minifying or magnifying + * 3. If minifying, choose mipmap levels + * 4. Return image filter to use within mipmap images + */ +static void +choose_mipmap_levels(struct tgsi_sampler *sampler, + const float s[QUAD_SIZE], + const float t[QUAD_SIZE], + const float p[QUAD_SIZE], + float lodbias, + unsigned *level0, unsigned *level1, float *levelBlend, + unsigned *imgFilter) +{ + if (sampler->state->min_mip_filter == PIPE_TEX_MIPFILTER_NONE) { + /* no mipmap selection needed */ + *imgFilter = sampler->state->mag_img_filter; + *level0 = *level1 = (int) sampler->state->min_lod; + } + else { + float lambda; + + if (1) + /* fragment shader */ + lambda = compute_lambda(sampler, s, t, p, lodbias); + else + /* vertex shader */ + lambda = lodbias; /* not really a bias, but absolute LOD */ + + if (lambda < 0.0) { /* XXX threshold depends on the filter */ + /* magnifying */ + *imgFilter = sampler->state->mag_img_filter; + *level0 = *level1 = 0; + } + else { + /* minifying */ + *imgFilter = sampler->state->min_img_filter; + + /* choose mipmap level(s) and compute the blend factor between them */ + if (sampler->state->min_mip_filter == PIPE_TEX_MIPFILTER_NEAREST) { + /* Nearest mipmap level */ + const int lvl = (int) (lambda + 0.5); + *level0 = + *level1 = CLAMP(lvl, 0, (int) sampler->texture->last_level); + } + else { + /* Linear interpolation between mipmap levels */ + const int lvl = (int) lambda; + *level0 = CLAMP(lvl, 0, (int) sampler->texture->last_level); + *level1 = CLAMP(lvl + 1, 0, (int) sampler->texture->last_level); + *levelBlend = FRAC(lambda); /* blending weight between levels */ + } + } + } +} + + +/** + * Get a texel from a texture, using the texture tile cache. + * + * \param face the cube face in 0..5 + * \param level the mipmap level + * \param x the x coord of texel within 2D image + * \param y the y coord of texel within 2D image + * \param z which slice of a 3D texture + * \param rgba the quad to put the texel/color into + * \param j which element of the rgba quad to write to + * + * XXX maybe move this into sp_tile_cache.c and merge with the + * sp_get_cached_tile_tex() function. Also, get 4 texels instead of 1... + */ +static void +get_texel(struct tgsi_sampler *sampler, + unsigned face, unsigned level, int x, int y, int z, + float rgba[NUM_CHANNELS][QUAD_SIZE], unsigned j) +{ + const int tx = x % TILE_SIZE; + const int ty = y % TILE_SIZE; + const struct softpipe_cached_tile *tile + = sp_get_cached_tile_tex(sampler->pipe, sampler->cache, + x, y, z, face, level); + rgba[0][j] = tile->data.color[ty][tx][0]; + rgba[1][j] = tile->data.color[ty][tx][1]; + rgba[2][j] = tile->data.color[ty][tx][2]; + rgba[3][j] = tile->data.color[ty][tx][3]; +} + + +/** + * Compare texcoord 'p' (aka R) against texture value 'rgba[0]' + * When we sampled the depth texture, the depth value was put into all + * RGBA channels. We look at the red channel here. + */ +static INLINE void +shadow_compare(uint compare_func, + float rgba[NUM_CHANNELS][QUAD_SIZE], + const float p[QUAD_SIZE], + uint j) +{ + int k; + switch (compare_func) { + case PIPE_FUNC_LESS: + k = p[j] < rgba[0][j]; + break; + case PIPE_FUNC_LEQUAL: + k = p[j] <= rgba[0][j]; + break; + case PIPE_FUNC_GREATER: + k = p[j] > rgba[0][j]; + break; + case PIPE_FUNC_GEQUAL: + k = p[j] >= rgba[0][j]; + break; + case PIPE_FUNC_EQUAL: + k = p[j] == rgba[0][j]; + break; + case PIPE_FUNC_NOTEQUAL: + k = p[j] != rgba[0][j]; + break; + case PIPE_FUNC_ALWAYS: + k = 1; + break; + case PIPE_FUNC_NEVER: + k = 0; + break; + default: + assert(0); + } + + rgba[0][j] = rgba[1][j] = rgba[2][j] = (float) k; +} + + +/** + * Common code for sampling 1D/2D/cube textures. + * Could probably extend for 3D... + */ +static void +sp_get_samples_2d_common(struct tgsi_sampler *sampler, + const float s[QUAD_SIZE], + const float t[QUAD_SIZE], + const float p[QUAD_SIZE], + float lodbias, + float rgba[NUM_CHANNELS][QUAD_SIZE], + const unsigned faces[4]) +{ + const uint compare_func = sampler->state->compare_func; + unsigned level0, level1, j, imgFilter; + int width, height; + float levelBlend; + + choose_mipmap_levels(sampler, s, t, p, lodbias, + &level0, &level1, &levelBlend, &imgFilter); + + if (sampler->state->normalized_coords) { + width = sampler->texture->width[level0]; + height = sampler->texture->height[level0]; + } + else { + width = height = 1; + } + + assert(width > 0); + + switch (imgFilter) { + case PIPE_TEX_FILTER_NEAREST: + for (j = 0; j < QUAD_SIZE; j++) { + int x = nearest_texcoord(sampler->state->wrap_s, s[j], width); + int y = nearest_texcoord(sampler->state->wrap_t, t[j], height); + get_texel(sampler, faces[j], level0, x, y, 0, rgba, j); + if (sampler->state->compare_mode == PIPE_TEX_COMPARE_R_TO_TEXTURE) { + shadow_compare(compare_func, rgba, p, j); + } + + if (level0 != level1) { + /* get texels from second mipmap level and blend */ + float rgba2[4][4]; + unsigned c; + x = x / 2; + y = y / 2; + get_texel(sampler, faces[j], level1, x, y, 0, rgba2, j); + if (sampler->state->compare_mode == PIPE_TEX_COMPARE_R_TO_TEXTURE){ + shadow_compare(compare_func, rgba2, p, j); + } + + for (c = 0; c < NUM_CHANNELS; c++) { + rgba[c][j] = LERP(levelBlend, rgba[c][j], rgba2[c][j]); + } + } + } + break; + case PIPE_TEX_FILTER_LINEAR: + for (j = 0; j < QUAD_SIZE; j++) { + float tx[4][4], a, b; + int x0, y0, x1, y1, c; + linear_texcoord(sampler->state->wrap_s, s[j], width, &x0, &x1, &a); + linear_texcoord(sampler->state->wrap_t, t[j], height, &y0, &y1, &b); + get_texel(sampler, faces[j], level0, x0, y0, 0, tx, 0); + get_texel(sampler, faces[j], level0, x1, y0, 0, tx, 1); + get_texel(sampler, faces[j], level0, x0, y1, 0, tx, 2); + get_texel(sampler, faces[j], level0, x1, y1, 0, tx, 3); + if (sampler->state->compare_mode == PIPE_TEX_COMPARE_R_TO_TEXTURE) { + shadow_compare(compare_func, tx, p, 0); + shadow_compare(compare_func, tx, p, 1); + shadow_compare(compare_func, tx, p, 2); + shadow_compare(compare_func, tx, p, 3); + } + + for (c = 0; c < 4; c++) { + rgba[c][j] = lerp_2d(a, b, tx[c][0], tx[c][1], tx[c][2], tx[c][3]); + } + + if (level0 != level1) { + /* get texels from second mipmap level and blend */ + float rgba2[4][4]; + x0 = x0 / 2; + y0 = y0 / 2; + x1 = x1 / 2; + y1 = y1 / 2; + get_texel(sampler, faces[j], level1, x0, y0, 0, tx, 0); + get_texel(sampler, faces[j], level1, x1, y0, 0, tx, 1); + get_texel(sampler, faces[j], level1, x0, y1, 0, tx, 2); + get_texel(sampler, faces[j], level1, x1, y1, 0, tx, 3); + if (sampler->state->compare_mode == PIPE_TEX_COMPARE_R_TO_TEXTURE){ + shadow_compare(compare_func, tx, p, 0); + shadow_compare(compare_func, tx, p, 1); + shadow_compare(compare_func, tx, p, 2); + shadow_compare(compare_func, tx, p, 3); + } + + for (c = 0; c < 4; c++) { + rgba2[c][j] = lerp_2d(a, b, + tx[c][0], tx[c][1], tx[c][2], tx[c][3]); + } + + for (c = 0; c < NUM_CHANNELS; c++) { + rgba[c][j] = LERP(levelBlend, rgba[c][j], rgba2[c][j]); + } + } + } + break; + default: + assert(0); + } +} + + +static void +sp_get_samples_1d(struct tgsi_sampler *sampler, + const float s[QUAD_SIZE], + const float t[QUAD_SIZE], + const float p[QUAD_SIZE], + float lodbias, + float rgba[NUM_CHANNELS][QUAD_SIZE]) +{ + static const unsigned faces[4] = {0, 0, 0, 0}; + static const float tzero[4] = {0, 0, 0, 0}; + sp_get_samples_2d_common(sampler, s, tzero, NULL, lodbias, rgba, faces); +} + + +static void +sp_get_samples_2d(struct tgsi_sampler *sampler, + const float s[QUAD_SIZE], + const float t[QUAD_SIZE], + const float p[QUAD_SIZE], + float lodbias, + float rgba[NUM_CHANNELS][QUAD_SIZE]) +{ + static const unsigned faces[4] = {0, 0, 0, 0}; + sp_get_samples_2d_common(sampler, s, t, p, lodbias, rgba, faces); +} + + +static void +sp_get_samples_3d(struct tgsi_sampler *sampler, + const float s[QUAD_SIZE], + const float t[QUAD_SIZE], + const float p[QUAD_SIZE], + float lodbias, + float rgba[NUM_CHANNELS][QUAD_SIZE]) +{ + /* get/map pipe_surfaces corresponding to 3D tex slices */ + unsigned level0, level1, j, imgFilter; + int width, height, depth; + float levelBlend; + const uint face = 0; + + choose_mipmap_levels(sampler, s, t, p, lodbias, + &level0, &level1, &levelBlend, &imgFilter); + + if (sampler->state->normalized_coords) { + width = sampler->texture->width[level0]; + height = sampler->texture->height[level0]; + depth = sampler->texture->depth[level0]; + } + else { + width = height = depth = 1; + } + + assert(width > 0); + assert(height > 0); + assert(depth > 0); + + switch (imgFilter) { + case PIPE_TEX_FILTER_NEAREST: + for (j = 0; j < QUAD_SIZE; j++) { + int x = nearest_texcoord(sampler->state->wrap_s, s[j], width); + int y = nearest_texcoord(sampler->state->wrap_t, t[j], height); + int z = nearest_texcoord(sampler->state->wrap_r, p[j], depth); + get_texel(sampler, face, level0, x, y, z, rgba, j); + + if (level0 != level1) { + /* get texels from second mipmap level and blend */ + float rgba2[4][4]; + unsigned c; + x /= 2; + y /= 2; + z /= 2; + get_texel(sampler, face, level1, x, y, z, rgba2, j); + for (c = 0; c < NUM_CHANNELS; c++) { + rgba[c][j] = LERP(levelBlend, rgba2[c][j], rgba[c][j]); + } + } + } + break; + case PIPE_TEX_FILTER_LINEAR: + for (j = 0; j < QUAD_SIZE; j++) { + float texel0[4][4], texel1[4][4]; + float xw, yw, zw; /* interpolation weights */ + int x0, x1, y0, y1, z0, z1, c; + linear_texcoord(sampler->state->wrap_s, s[j], width, &x0, &x1, &xw); + linear_texcoord(sampler->state->wrap_t, t[j], height, &y0, &y1, &yw); + linear_texcoord(sampler->state->wrap_r, p[j], depth, &z0, &z1, &zw); + get_texel(sampler, face, level0, x0, y0, z0, texel0, 0); + get_texel(sampler, face, level0, x1, y0, z0, texel0, 1); + get_texel(sampler, face, level0, x0, y1, z0, texel0, 2); + get_texel(sampler, face, level0, x1, y1, z0, texel0, 3); + get_texel(sampler, face, level0, x0, y0, z1, texel1, 0); + get_texel(sampler, face, level0, x1, y0, z1, texel1, 1); + get_texel(sampler, face, level0, x0, y1, z1, texel1, 2); + get_texel(sampler, face, level0, x1, y1, z1, texel1, 3); + + /* 3D lerp */ + for (c = 0; c < 4; c++) { + float ctemp0[4][4], ctemp1[4][4]; + ctemp0[c][j] = lerp_2d(xw, yw, + texel0[c][0], texel0[c][1], + texel0[c][2], texel0[c][3]); + ctemp1[c][j] = lerp_2d(xw, yw, + texel1[c][0], texel1[c][1], + texel1[c][2], texel1[c][3]); + rgba[c][j] = LERP(zw, ctemp0[c][j], ctemp1[c][j]); + } + + if (level0 != level1) { + /* get texels from second mipmap level and blend */ + float rgba2[4][4]; + x0 /= 2; + y0 /= 2; + z0 /= 2; + x1 /= 2; + y1 /= 2; + z1 /= 2; + get_texel(sampler, face, level1, x0, y0, z0, texel0, 0); + get_texel(sampler, face, level1, x1, y0, z0, texel0, 1); + get_texel(sampler, face, level1, x0, y1, z0, texel0, 2); + get_texel(sampler, face, level1, x1, y1, z0, texel0, 3); + get_texel(sampler, face, level1, x0, y0, z1, texel1, 0); + get_texel(sampler, face, level1, x1, y0, z1, texel1, 1); + get_texel(sampler, face, level1, x0, y1, z1, texel1, 2); + get_texel(sampler, face, level1, x1, y1, z1, texel1, 3); + + /* 3D lerp */ + for (c = 0; c < 4; c++) { + float ctemp0[4][4], ctemp1[4][4]; + ctemp0[c][j] = lerp_2d(xw, yw, + texel0[c][0], texel0[c][1], + texel0[c][2], texel0[c][3]); + ctemp1[c][j] = lerp_2d(xw, yw, + texel1[c][0], texel1[c][1], + texel1[c][2], texel1[c][3]); + rgba2[c][j] = LERP(zw, ctemp0[c][j], ctemp1[c][j]); + } + + /* blend mipmap levels */ + for (c = 0; c < NUM_CHANNELS; c++) { + rgba[c][j] = LERP(levelBlend, rgba[c][j], rgba2[c][j]); + } + } + } + break; + default: + assert(0); + } +} + + +static void +sp_get_samples_cube(struct tgsi_sampler *sampler, + const float s[QUAD_SIZE], + const float t[QUAD_SIZE], + const float p[QUAD_SIZE], + float lodbias, + float rgba[NUM_CHANNELS][QUAD_SIZE]) +{ + unsigned faces[QUAD_SIZE], j; + float ssss[4], tttt[4]; + for (j = 0; j < QUAD_SIZE; j++) { + faces[j] = choose_cube_face(s[j], t[j], p[j], ssss + j, tttt + j); + } + sp_get_samples_2d_common(sampler, ssss, tttt, NULL, lodbias, rgba, faces); +} + + +/** + * Called via tgsi_sampler::get_samples() + * Use the sampler's state setting to get a filtered RGBA value + * from the sampler's texture. + * + * 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.... + */ +void +sp_get_samples(struct tgsi_sampler *sampler, + const float s[QUAD_SIZE], + const float t[QUAD_SIZE], + const float p[QUAD_SIZE], + float lodbias, + float rgba[NUM_CHANNELS][QUAD_SIZE]) +{ + if (!sampler->texture) + return; + + switch (sampler->texture->target) { + case PIPE_TEXTURE_1D: + sp_get_samples_1d(sampler, s, t, p, lodbias, rgba); + break; + case PIPE_TEXTURE_2D: + sp_get_samples_2d(sampler, s, t, p, lodbias, rgba); + break; + case PIPE_TEXTURE_3D: + sp_get_samples_3d(sampler, s, t, p, lodbias, rgba); + break; + case PIPE_TEXTURE_CUBE: + sp_get_samples_cube(sampler, s, t, p, lodbias, rgba); + break; + default: + assert(0); + } +} + |