diff options
Diffstat (limited to 'src/mesa')
| -rw-r--r-- | src/mesa/pipe/softpipe/sp_tex_sample.c | 166 | ||||
| -rw-r--r-- | src/mesa/pipe/softpipe/sp_tex_sample.h | 13 |
2 files changed, 179 insertions, 0 deletions
diff --git a/src/mesa/pipe/softpipe/sp_tex_sample.c b/src/mesa/pipe/softpipe/sp_tex_sample.c new file mode 100644 index 0000000000..e501cea5ad --- /dev/null +++ b/src/mesa/pipe/softpipe/sp_tex_sample.c @@ -0,0 +1,166 @@ +/************************************************************************** + * + * 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_surface.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" + + +#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); +} + + +/** + * Apply texture coord wrapping mode and return integer texture + * row/column/img index. + */ +static INLINE void +nearest_texcoord(GLuint wrapMode, GLfloat s, GLuint width, GLint *k) +{ + /* XXX this arithmetic isn't exactly right, add more wrap modes */ + switch (wrapMode) { + case PIPE_TEX_WRAP_REPEAT: + *k = (int) (s * width) % width; + break; + case PIPE_TEX_WRAP_CLAMP: + *k = (int) CLAMP(s, 0.0, 1.0) * width; + break; + default: + assert(0); + *k = 0; + } +} + +static INLINE void +linear_texcoord(GLuint wrapMode, GLfloat s, GLuint width, GLint *k0, GLint *k1, + GLfloat *a) +{ + /* XXX this arithmetic isn't exactly right, add more wrap modes */ + switch (wrapMode) { + case PIPE_TEX_WRAP_REPEAT: + *k0 = (int) (s * width) % width; + *k1 = (*k0 + 1) % width; + break; + case PIPE_TEX_WRAP_CLAMP: + *k0 = (int) CLAMP(s, 0.0, 1.0) * width; + *k1 = (*k0 + 1); + if (*k1 >= width) + *k1 = width - 1; + break; + default: + assert(0); + *k0 = *k1 = 0; + } + /* kludge the lerp weight: */ + *a = (s * width) - (int) (s * width); +} + + +/** + * 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.... + */ +void +sp_get_sample(struct tgsi_sampler *sampler, + const GLfloat strq[4], 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, y; + nearest_texcoord(sampler->state->wrap_s, strq[0], + sampler->texture->width0, &x); + nearest_texcoord(sampler->state->wrap_t, strq[1], + sampler->texture->height0, &y); + ps->get_tile(ps, x, y, 1, 1, rgba); + } + break; + case PIPE_TEX_FILTER_LINEAR: + { + GLfloat t00[4], t01[4], t10[4], t11[4]; + GLint x0, y0, x1, y1; + GLfloat a, b; + 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; + default: + assert(0); + } +} diff --git a/src/mesa/pipe/softpipe/sp_tex_sample.h b/src/mesa/pipe/softpipe/sp_tex_sample.h new file mode 100644 index 0000000000..d1d40e4a2f --- /dev/null +++ b/src/mesa/pipe/softpipe/sp_tex_sample.h @@ -0,0 +1,13 @@ +#ifndef SP_TEX_SAMPLE_H +#define SP_TEX_SAMPLE_H + + +struct tgsi_sampler; + + +extern void +sp_get_sample(struct tgsi_sampler *sampler, + const GLfloat strq[4], GLfloat rgba[4]); + + +#endif /* SP_TEX_SAMPLE_H */ |