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fix rectangle texture clamping and border-related code

This commit is contained in:
Brian Paul 2004-05-06 20:28:26 +00:00
parent 1229100703
commit 4ab8b77520
1 changed files with 72 additions and 23 deletions
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95
src/mesa/swrast/s_texture.c
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@ -2171,7 +2171,10 @@ sample_nearest_rect(GLcontext *ctx, GLuint texUnit,
GLint row, col;
/* NOTE: we DO NOT use [0, 1] texture coordinates! */
if (tObj->WrapS == GL_CLAMP) {
col = IFLOOR( CLAMP(texcoords[i][0], 0.0F, width) );
/* Note: we use width-1, not what the spec says, but it actually
* does work correctly.
*/
col = IFLOOR( CLAMP(texcoords[i][0], 0.0F, width - 1) );
}
else if (tObj->WrapS == GL_CLAMP_TO_EDGE) {
col = IFLOOR( CLAMP(texcoords[i][0], 0.5F, width - 0.5F) );
@ -2180,7 +2183,7 @@ sample_nearest_rect(GLcontext *ctx, GLuint texUnit,
col = IFLOOR( CLAMP(texcoords[i][0], -0.5F, width + 0.5F) );
}
if (tObj->WrapT == GL_CLAMP) {
row = IFLOOR( CLAMP(texcoords[i][1], 0.0F, height) );
row = IFLOOR( CLAMP(texcoords[i][1], 0.0F, height - 1) );
}
else if (tObj->WrapT == GL_CLAMP_TO_EDGE) {
row = IFLOOR( CLAMP(texcoords[i][1], 0.5F, height - 0.5F) );
@ -2189,10 +2192,10 @@ sample_nearest_rect(GLcontext *ctx, GLuint texUnit,
row = IFLOOR( CLAMP(texcoords[i][1], -0.5F, height + 0.5F) );
}
col = CLAMP(col, 0, width_minus_1);
row = CLAMP(row, 0, height_minus_1);
img->FetchTexelc(img, col, row, 0, rgba[i]);
if (col < 0 || col > width_minus_1 || row < 0 || row > height_minus_1)
COPY_CHAN4(rgba[i], tObj->_BorderChan);
else
img->FetchTexelc(img, col, row, 0, rgba[i]);
}
}
@ -2224,45 +2227,91 @@ sample_linear_rect(GLcontext *ctx, GLuint texUnit,
/* XXX lots of opportunity for optimization in this loop */
for (i = 0; i < n; i++) {
GLfloat frow, fcol;
GLint row0, col0, row1, col1;
GLint i0, j0, i1, j1;
GLchan t00[4], t01[4], t10[4], t11[4];
GLfloat a, b, w00, w01, w10, w11;
GLuint useBorderColor = 0;
/* NOTE: we DO NOT use [0, 1] texture coordinates! */
if (tObj->WrapS == GL_CLAMP) {
fcol = CLAMP(texcoords[i][0], 0.0F, width);
/* clamping to width-1 looks wrong, but it's really correct */
fcol = CLAMP(texcoords[i][0], 0.0F, width_minus_1);
i0 = IFLOOR(fcol);
i1 = i0 + 1;
}
else if (tObj->WrapS == GL_CLAMP_TO_EDGE) {
fcol = CLAMP(texcoords[i][0], 0.5F, width - 0.5F);
i0 = IFLOOR(fcol);
i1 = i0 + 1;
if (i1 > width_minus_1)
i1 = width_minus_1;
}
else {
else { /* GL_CLAMP_TO_BORDER */
#if 0
/* literal reading of GL_NV_texture_rectangle spec */
fcol = CLAMP(texcoords[i][0], -0.5F, width + 0.5F);
i0 = IFLOOR(fcol);
i1 = i0 + 1;
#else
/* Note: this produces results that matches NVIDIA, but it's not
* exactly what the GL_NV_texture_rectangle specifies!
*/
fcol = texcoords[i][0];
i0 = IFLOOR(fcol);
i1 = i0 + 1;
#endif
}
if (tObj->WrapT == GL_CLAMP) {
frow = CLAMP(texcoords[i][1], 0.0F, height);
frow = CLAMP(texcoords[i][1], 0.0F, height_minus_1);
j0 = IFLOOR(frow);
j1 = j0 + 1;
}
else if (tObj->WrapT == GL_CLAMP_TO_EDGE) {
frow = CLAMP(texcoords[i][1], 0.5F, height - 0.5F);
j0 = IFLOOR(frow);
j1 = j0 + 1;
if (j1 > height_minus_1)
j1 = height_minus_1;
}
else {
else { /* GL_CLAMP_TO_BORDER */
#if 0
frow = CLAMP(texcoords[i][1], -0.5F, height + 0.5F);
j0 = IFLOOR(frow);
j1 = j0 + 1;
#else
frow = texcoords[i][1];
j0 = IFLOOR(frow);
j1 = j0 + 1;
#endif
}
/* compute integer rows/columns */
col0 = IFLOOR(fcol);
col1 = col0 + 1;
col0 = CLAMP(col0, 0, width_minus_1);
col1 = CLAMP(col1, 0, width_minus_1);
row0 = IFLOOR(frow);
row1 = row0 + 1;
row0 = CLAMP(row0, 0, height_minus_1);
row1 = CLAMP(row1, 0, height_minus_1);
if (i0 < 0 || i0 > width_minus_1) useBorderColor |= I0BIT;
if (i1 < 0 || i1 > width_minus_1) useBorderColor |= I1BIT;
if (j0 < 0 || j0 > height_minus_1) useBorderColor |= J0BIT;
if (j1 < 0 || j1 > height_minus_1) useBorderColor |= J1BIT;
/* get four texel samples */
img->FetchTexelc(img, col0, row0, 0, t00);
img->FetchTexelc(img, col1, row0, 0, t10);
img->FetchTexelc(img, col0, row1, 0, t01);
img->FetchTexelc(img, col1, row1, 0, t11);
if (useBorderColor & (I0BIT | J0BIT))
COPY_CHAN4(t00, tObj->_BorderChan);
else
img->FetchTexelc(img, i0, j0, 0, t00);
if (useBorderColor & (I1BIT | J0BIT))
COPY_CHAN4(t10, tObj->_BorderChan);
else
img->FetchTexelc(img, i1, j0, 0, t10);
if (useBorderColor & (I0BIT | J1BIT))
COPY_CHAN4(t01, tObj->_BorderChan);
else
img->FetchTexelc(img, i0, j1, 0, t01);
if (useBorderColor & (I1BIT | J1BIT))
COPY_CHAN4(t11, tObj->_BorderChan);
else
img->FetchTexelc(img, i1, j1, 0, t11);
/* compute sample weights */
a = FRAC(fcol);