diff options
| -rw-r--r-- | src/mesa/swrast/s_texture.c | 53 |
1 files changed, 41 insertions, 12 deletions
diff --git a/src/mesa/swrast/s_texture.c b/src/mesa/swrast/s_texture.c index 55c5277fd33..7f932f8b13e 100644 --- a/src/mesa/swrast/s_texture.c +++ b/src/mesa/swrast/s_texture.c @@ -1,4 +1,4 @@ -/* $Id: s_texture.c,v 1.22 2001/04/10 15:25:45 brianp Exp $ */ +/* $Id: s_texture.c,v 1.23 2001/04/12 15:18:07 brianp Exp $ */ /* * Mesa 3-D graphics library @@ -199,6 +199,15 @@ +/* + * Note, the FRAC macro has to work perfectly. Otherwise you'll sometimes + * see 1-pixel bands of improperly weighted linear-sampled texels. + * In particular, #define FRAC(f) ((f) - IFLOOR(f)) doesn't work. + * 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) - floor(f)) + /* * Bitflags for texture border color sampling. @@ -285,9 +294,15 @@ sample_1d_nearest(GLcontext *ctx, /* skip over the border, if any */ i += img->Border; - (*img->FetchTexel)(img, i, 0, 0, (GLvoid *) rgba); - if (img->Format == GL_COLOR_INDEX) { - palette_sample(ctx, tObj, rgba[0], rgba); + if (i < 0 || i >= img->Width) { + /* Need this test for GL_CLAMP_TO_BORDER_ARB mode */ + COPY_CHAN4(rgba, tObj->BorderColor); + } + else { + (*img->FetchTexel)(img, i, 0, 0, (GLvoid *) rgba); + if (img->Format == GL_COLOR_INDEX) { + palette_sample(ctx, tObj, rgba[0], rgba); + } } } @@ -569,9 +584,15 @@ sample_2d_nearest(GLcontext *ctx, i += img->Border; j += img->Border; - (*img->FetchTexel)(img, i, j, 0, (GLvoid *) rgba); - if (img->Format == GL_COLOR_INDEX) { - palette_sample(ctx, tObj, rgba[0], rgba); + if (i < 0 || i >= img->Width || j < 0 || j >= img->Height) { + /* Need this test for GL_CLAMP_TO_BORDER_ARB mode */ + COPY_CHAN4(rgba, tObj->BorderColor); + } + else { + (*img->FetchTexel)(img, i, j, 0, (GLvoid *) rgba); + if (img->Format == GL_COLOR_INDEX) { + palette_sample(ctx, tObj, rgba[0], rgba); + } } } @@ -612,8 +633,8 @@ sample_2d_linear(GLcontext *ctx, } { - const GLfloat a = FRAC(u + 1.0F); /* add one in case u is just below 0 */ - const GLfloat b = FRAC(v + 1.0F); + const GLfloat a = FRAC(u - 1.0); + const GLfloat b = FRAC(v - 1.0); /* compute sample weights in fixed point in [0,WEIGHT_SCALE] */ const GLint w00 = IROUND_POS((1.0F-a) * (1.0F-b) * WEIGHT_SCALE); const GLint w10 = IROUND_POS( a * (1.0F-b) * WEIGHT_SCALE); @@ -983,9 +1004,17 @@ sample_3d_nearest(GLcontext *ctx, COMPUTE_NEAREST_TEXEL_LOCATION(tObj->WrapT, t, height, j); COMPUTE_NEAREST_TEXEL_LOCATION(tObj->WrapR, r, depth, k); - (*img->FetchTexel)(img, i, j, k, (GLvoid *) rgba); - if (img->Format == GL_COLOR_INDEX) { - palette_sample(ctx, tObj, rgba[0], rgba); + if (i < 0 || i >= img->Width || + j < 0 || j >= img->Height || + k < 0 || k >= img->Depth) { + /* Need this test for GL_CLAMP_TO_BORDER_ARB mode */ + COPY_CHAN4(rgba, tObj->BorderColor); + } + else { + (*img->FetchTexel)(img, i, j, k, (GLvoid *) rgba); + if (img->Format == GL_COLOR_INDEX) { + palette_sample(ctx, tObj, rgba[0], rgba); + } } } |