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-rw-r--r--src/mesa/pipe/softpipe/sp_tex_sample.c284
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;
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-22 22:23:00 +0000