diff options
| -rw-r--r-- | src/mesa/swrast/s_texture.c | 280 |
1 files changed, 251 insertions, 29 deletions
diff --git a/src/mesa/swrast/s_texture.c b/src/mesa/swrast/s_texture.c index 62439af94c..9c60c695c3 100644 --- a/src/mesa/swrast/s_texture.c +++ b/src/mesa/swrast/s_texture.c @@ -1,4 +1,4 @@ -/* $Id: s_texture.c,v 1.12 2001/02/20 16:42:26 brianp Exp $ */ +/* $Id: s_texture.c,v 1.13 2001/02/26 18:24:37 brianp Exp $ */ /* * Mesa 3-D graphics library @@ -49,6 +49,13 @@ /* * Used to compute texel locations for linear sampling. + * Input: + * wrapMode = GL_REPEAT, GL_CLAMP or GL_CLAMP_TO_EDGE + * S = texcoord in [0,1] + * SIZE = width (or height or depth) of texture + * Output: + * U = texcoord in [0, width] + * I0, I1 = two nearest texel indexes */ #define COMPUTE_LINEAR_TEXEL_LOCATIONS(wrapMode, S, U, SIZE, I0, I1) \ { \ @@ -2341,12 +2348,12 @@ apply_texture( const GLcontext *ctx, /* - * Apply a shadow/depth texture to the array of colors. + * Sample a shadow/depth texture. * Input: ctx - context * texUnit - the texture unit - * n - number of colors - * r - array [n] of texture R coordinates - * In/Out: rgba - array [n] of colors. + * n - number of samples + * s,t,r - array [n] of texture coordinates + * In/Out: rgba - array [n] of texel colors. */ static void sample_depth_texture(const GLcontext *ctx, @@ -2356,10 +2363,31 @@ sample_depth_texture(const GLcontext *ctx, GLchan texel[][4]) { const struct gl_texture_object *texObj = texUnit->_Current; - const struct gl_texture_image *texImage = texObj->Image[0]; /* XXX hack */ + const GLint baseLevel = texObj->BaseLevel; + const struct gl_texture_image *texImage = texObj->Image[baseLevel]; + const GLuint width = texImage->Width; + const GLuint height = texImage->Height; const GLchan ambient = texObj->ShadowAmbient; GLboolean lequal, gequal; - GLuint i; + + if (texObj->Dimensions != 2) { + gl_problem(ctx, "only 2-D depth textures supported at this time"); + return; + } + + if (texObj->MinFilter != texObj->MagFilter) { + gl_problem(ctx, "mipmapped depth textures not supported at this time"); + return; + } + + /* XXX the GL_SGIX_shadow extension spec doesn't say what to do if + * GL_TEXTURE_COMPARE_SGIX == GL_TRUE but the current texture object + * isn't a depth texture. + */ + if (texImage->Format != GL_DEPTH_COMPONENT) { + gl_problem(ctx,"GL_TEXTURE_COMPARE_SGIX enabled with non-depth texture"); + return; + } if (texObj->CompareOperator == GL_TEXTURE_LEQUAL_R_SGIX) { lequal = GL_TRUE; @@ -2370,34 +2398,228 @@ sample_depth_texture(const GLcontext *ctx, gequal = GL_TRUE; } - assert(texObj->Dimensions == 2); - assert(texImage->Format == GL_DEPTH_COMPONENT); + if (texObj->MagFilter == GL_NEAREST) { + GLuint i; + for (i = 0; i < n; i++) { + GLfloat depthSample; + GLint col, row; + COMPUTE_NEAREST_TEXEL_LOCATION(texObj->WrapS, s[i], width, col); + COMPUTE_NEAREST_TEXEL_LOCATION(texObj->WrapT, t[i], height, row); + depthSample = *((const GLfloat *) texImage->Data + row * width + col); + if ((depthSample <= r[i] && lequal) || + (depthSample >= r[i] && gequal)) { + texel[i][RCOMP] = ambient; + texel[i][GCOMP] = ambient; + texel[i][BCOMP] = ambient; + texel[i][ACOMP] = CHAN_MAX; + } + else { + texel[i][RCOMP] = CHAN_MAX; + texel[i][GCOMP] = CHAN_MAX; + texel[i][BCOMP] = CHAN_MAX; + texel[i][ACOMP] = CHAN_MAX; + } + } + } + else { + GLuint i; + ASSERT(texObj->MagFilter == GL_LINEAR); + for (i = 0; i < n; i++) { + GLfloat depth00, depth01, depth10, depth11; + GLint i0, i1, j0, j1; + GLfloat u, v; + GLuint useBorderTexel; + + COMPUTE_LINEAR_TEXEL_LOCATIONS(texObj->WrapS, s[i], u, width, i0, i1); + COMPUTE_LINEAR_TEXEL_LOCATIONS(texObj->WrapT, t[i], v, height,j0, j1); + + useBorderTexel = 0; + if (texImage->Border) { + i0 += texImage->Border; + i1 += texImage->Border; + j0 += texImage->Border; + j1 += texImage->Border; + } + else { + if (i0 < 0 || i0 >= width) useBorderTexel |= I0BIT; + if (i1 < 0 || i1 >= width) useBorderTexel |= I1BIT; + if (j0 < 0 || j0 >= height) useBorderTexel |= J0BIT; + if (j1 < 0 || j1 >= height) useBorderTexel |= J1BIT; + } - for (i = 0; i < n; i++) { - const GLfloat *src; - GLfloat depthSample; - GLint col, row; - /* XXX this is a hack - implement proper sampling */ - COMPUTE_NEAREST_TEXEL_LOCATION(texObj->WrapS, s[i], texImage->Width, col); - COMPUTE_NEAREST_TEXEL_LOCATION(texObj->WrapT, t[i], texImage->Height,row); - src = (const GLfloat *) texImage->Data + row * texImage->Width + col; - depthSample = *src; - if ((depthSample <= r[i] && lequal) || - (depthSample >= r[i] && gequal)) { - texel[i][RCOMP] = ambient; - texel[i][GCOMP] = ambient; - texel[i][BCOMP] = ambient; - texel[i][ACOMP] = CHAN_MAX; + /* get four depth samples from the texture */ + if (useBorderTexel & (I0BIT | J0BIT)) { + depth00 = 1.0; + } + else { + depth00 = *((const GLfloat *) texImage->Data + j0 * width + i0); + } + if (useBorderTexel & (I1BIT | J0BIT)) { + depth10 = 1.0; + } + else { + depth10 = *((const GLfloat *) texImage->Data + j0 * width + i1); + } + if (useBorderTexel & (I0BIT | J1BIT)) { + depth01 = 1.0; + } + else { + depth01 = *((const GLfloat *) texImage->Data + j1 * width + i0); + } + if (useBorderTexel & (I1BIT | J1BIT)) { + depth11 = 1.0; + } + else { + depth11 = *((const GLfloat *) texImage->Data + j1 * width + i1); + } + + if (0) { + /* compute a single weighted depth sample and do one comparison */ + const GLfloat a = FRAC(u); + const GLfloat b = FRAC(v); + const GLfloat w00 = (1.0F - a) * (1.0F - b); + const GLfloat w10 = ( a) * (1.0F - b); + const GLfloat w01 = (1.0F - a) * ( b); + const GLfloat w11 = ( a) * ( b); + const GLfloat depthSample = w00 * depth00 + w10 * depth10 + + w01 * depth01 + w11 * depth11; + if ((depthSample <= r[i] && lequal) || + (depthSample >= r[i] && gequal)) { + texel[i][RCOMP] = ambient; + texel[i][GCOMP] = ambient; + texel[i][BCOMP] = ambient; + texel[i][ACOMP] = CHAN_MAX; + } + else { + texel[i][RCOMP] = CHAN_MAX; + texel[i][GCOMP] = CHAN_MAX; + texel[i][BCOMP] = CHAN_MAX; + texel[i][ACOMP] = CHAN_MAX; + } + } + else { + /* Do four depth/R comparisons and compute a weighted result. + * If this touches on somebody's I.P., I'll remove this code + * upon request. + */ + const GLfloat d = (CHAN_MAXF - (GLfloat) ambient) * 0.25F; + GLfloat luminance = CHAN_MAXF; + GLchan lum; + if (lequal) { + if (depth00 <= r[i]) luminance -= d; + if (depth01 <= r[i]) luminance -= d; + if (depth10 <= r[i]) luminance -= d; + if (depth11 <= r[i]) luminance -= d; + } + else { + if (depth00 >= r[i]) luminance -= d; + if (depth01 >= r[i]) luminance -= d; + if (depth10 >= r[i]) luminance -= d; + if (depth11 >= r[i]) luminance -= d; + } + lum = (GLchan) luminance; + texel[i][RCOMP] = lum; + texel[i][GCOMP] = lum; + texel[i][BCOMP] = lum; + texel[i][ACOMP] = CHAN_MAX; + } } - else { - texel[i][RCOMP] = CHAN_MAX; - texel[i][GCOMP] = CHAN_MAX; - texel[i][BCOMP] = CHAN_MAX; + } +} + + +#if 0 +/* + * Experimental depth texture sampling function. + */ +static void +sample_depth_texture2(const GLcontext *ctx, + const struct gl_texture_unit *texUnit, + GLuint n, + const GLfloat s[], const GLfloat t[], const GLfloat r[], + GLchan texel[][4]) +{ + const struct gl_texture_object *texObj = texUnit->_Current; + const GLint baseLevel = texObj->BaseLevel; + const struct gl_texture_image *texImage = texObj->Image[baseLevel]; + const GLuint width = texImage->Width; + const GLuint height = texImage->Height; + const GLchan ambient = texObj->ShadowAmbient; + GLboolean lequal, gequal; + + if (texObj->Dimensions != 2) { + gl_problem(ctx, "only 2-D depth textures supported at this time"); + return; + } + + if (texObj->MinFilter != texObj->MagFilter) { + gl_problem(ctx, "mipmapped depth textures not supported at this time"); + return; + } + + /* XXX the GL_SGIX_shadow extension spec doesn't say what to do if + * GL_TEXTURE_COMPARE_SGIX == GL_TRUE but the current texture object + * isn't a depth texture. + */ + if (texImage->Format != GL_DEPTH_COMPONENT) { + gl_problem(ctx,"GL_TEXTURE_COMPARE_SGIX enabled with non-depth texture"); + return; + } + + if (texObj->CompareOperator == GL_TEXTURE_LEQUAL_R_SGIX) { + lequal = GL_TRUE; + gequal = GL_FALSE; + } + else { + lequal = GL_FALSE; + gequal = GL_TRUE; + } + + { + GLuint i; + for (i = 0; i < n; i++) { + const GLint K = 3; + GLint col, row, ii, jj, imin, imax, jmin, jmax, samples, count; + GLfloat w; + GLchan lum; + COMPUTE_NEAREST_TEXEL_LOCATION(texObj->WrapS, s[i], width, col); + COMPUTE_NEAREST_TEXEL_LOCATION(texObj->WrapT, t[i], height, row); + + imin = col - K; + imax = col + K; + jmin = row - K; + jmax = row + K; + + if (imin < 0) imin = 0; + if (imax >= width) imax = width - 1; + if (jmin < 0) jmin = 0; + if (jmax >= height) jmax = height - 1; + + samples = (imax - imin + 1) * (jmax - jmin + 1); + count = 0; + for (jj = jmin; jj <= jmax; jj++) { + for (ii = imin; ii <= imax; ii++) { + GLfloat depthSample = *((const GLfloat *) texImage->Data + + jj * width + ii); + if ((depthSample <= r[i] && lequal) || + (depthSample >= r[i] && gequal)) { + count++; + } + } + } + + w = (GLfloat) count / (GLfloat) samples; + w = CHAN_MAXF - w * (CHAN_MAXF - (GLfloat) ambient); + lum = (GLint) w; + + texel[i][RCOMP] = lum; + texel[i][GCOMP] = lum; + texel[i][BCOMP] = lum; texel[i][ACOMP] = CHAN_MAX; } } } - +#endif /* |