diff options
| -rw-r--r-- | src/mesa/pipe/softpipe/sp_tex_sample.c | 284 |
1 files changed, 257 insertions, 27 deletions
diff --git a/src/mesa/pipe/softpipe/sp_tex_sample.c b/src/mesa/pipe/softpipe/sp_tex_sample.c index e501cea5ad6..de8e01ea07e 100644 --- a/src/mesa/pipe/softpipe/sp_tex_sample.c +++ b/src/mesa/pipe/softpipe/sp_tex_sample.c @@ -34,7 +34,7 @@ #include "main/macros.h" -#include "sp_surface.h" +#include "sp_context.h" #include "sp_surface.h" #include "sp_tex_sample.h" #include "pipe/p_context.h" @@ -42,6 +42,19 @@ #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)) ) @@ -64,51 +77,268 @@ lerp_2d(GLfloat a, GLfloat b, /** - * Apply texture coord wrapping mode and return integer texture - * row/column/img index. + * Compute the remainder of a divided by b, but be careful with + * negative values so that REPEAT mode works right. */ -static INLINE void -nearest_texcoord(GLuint wrapMode, GLfloat s, GLuint width, GLint *k) +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) { - /* XXX this arithmetic isn't exactly right, add more wrap modes */ + GLint i; switch (wrapMode) { case PIPE_TEX_WRAP_REPEAT: - *k = (int) (s * width) % width; - break; + /* 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: - *k = (int) CLAMP(s, 0.0, 1.0) * width; - break; + /* 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); - *k = 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 width, GLint *k0, GLint *k1, - GLfloat *a) +linear_texcoord(GLuint wrapMode, GLfloat s, GLuint size, + GLint *i0, GLint *i1, GLfloat *a) { - /* XXX this arithmetic isn't exactly right, add more wrap modes */ + GLfloat u; switch (wrapMode) { case PIPE_TEX_WRAP_REPEAT: - *k0 = (int) (s * width) % width; - *k1 = (*k0 + 1) % width; + u = s * size - 0.5F; + *i0 = repeat_remainder(IFLOOR(u), size); + *i1 = repeat_remainder(*i0 + 1, size); break; case PIPE_TEX_WRAP_CLAMP: - *k0 = (int) CLAMP(s, 0.0, 1.0) * width; - *k1 = (*k0 + 1); - if (*k1 >= width) - *k1 = width - 1; + 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); - *k0 = *k1 = 0; } - /* kludge the lerp weight: */ - *a = (s * width) - (int) (s * width); + *a = FRAC(u); } + /** * Called via tgsi_sampler::get_sample() * Use the sampler's state setting to get a filtered RGBA value @@ -133,10 +363,10 @@ sp_get_sample(struct tgsi_sampler *sampler, 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); + x = nearest_texcoord(sampler->state->wrap_s, strq[0], + sampler->texture->width0); + y = nearest_texcoord(sampler->state->wrap_t, strq[1], + sampler->texture->height0); ps->get_tile(ps, x, y, 1, 1, rgba); } break; |