From 4ab8b77520f77a7a28a688c7599c917703f1a5e7 Mon Sep 17 00:00:00 2001 From: Brian Paul Date: Thu, 6 May 2004 20:28:26 +0000 Subject: fix rectangle texture clamping and border-related code --- src/mesa/swrast/s_texture.c | 95 ++++++++++++++++++++++++++++++++++----------- 1 file changed, 72 insertions(+), 23 deletions(-) diff --git a/src/mesa/swrast/s_texture.c b/src/mesa/swrast/s_texture.c index 22d193381b..6a4b7f7303 100644 --- a/src/mesa/swrast/s_texture.c +++ b/src/mesa/swrast/s_texture.c @@ -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); -- cgit v1.2.3