/* * Mesa 3-D graphics library * Version: 7.3 * * Copyright (C) 1999-2008 Brian Paul All Rights Reserved. * * Permission is hereby granted, free of charge, to any person obtaining a * copy of this software and associated documentation files (the "Software"), * to deal in the Software without restriction, including without limitation * the rights to use, copy, modify, merge, publish, distribute, sublicense, * and/or sell copies of the Software, and to permit persons to whom the * Software is furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included * in all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ #include /* * 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)) ) /** * Do 2D/biliner interpolation of float values. * v00, v10, v01 and v11 are typically four texture samples in a square/box. * a and b are the horizontal and vertical interpolants. * It's important that this function is inlined when compiled with * optimization! If we find that's not true on some systems, convert * to a macro. */ static inline GLfloat lerp_2d(GLfloat a, GLfloat b, GLfloat v00, GLfloat v10, GLfloat v01, GLfloat v11) { const GLfloat temp0 = LERP(a, v00, v10); const GLfloat temp1 = LERP(a, v01, v11); return LERP(b, temp0, temp1); } /** * Do linear interpolation of colors. */ static inline void lerp_rgba(GLfloat result[4], GLfloat t, const GLfloat a[4], const GLfloat b[4]) { result[0] = LERP(t, a[0], b[0]); result[1] = LERP(t, a[1], b[1]); result[2] = LERP(t, a[2], b[2]); result[3] = LERP(t, a[3], b[3]); } /** * Do bilinear interpolation of colors. */ static inline void lerp_rgba_2d(GLfloat result[4], GLfloat a, GLfloat b, const GLfloat t00[4], const GLfloat t10[4], const GLfloat t01[4], const GLfloat t11[4]) { result[0] = lerp_2d(a, b, t00[0], t10[0], t01[0], t11[0]); result[1] = lerp_2d(a, b, t00[1], t10[1], t01[1], t11[1]); result[2] = lerp_2d(a, b, t00[2], t10[2], t01[2], t11[2]); result[3] = lerp_2d(a, b, t00[3], t10[3], t01[3], t11[3]); } /** * Used for GL_REPEAT wrap mode. Using A % B doesn't produce the * right results for A<0. Casting to A to be unsigned only works if B * is a power of two. Adding a bias to A (which is a multiple of B) * avoids the problems with A < 0 (for reasonable A) without using a * conditional. */ #define REMAINDER(A, B) (((A) + (B) * 1024) % (B)) /** * Used to compute texel locations for linear sampling. * Input: * wrapMode = GL_REPEAT, GL_CLAMP * s = texcoord in [0,1] * size = width (or height or depth) of texture * Output: * i0, i1 = returns two nearest texel indexes * weight = returns blend factor between texels */ static inline void linear_texel_locations(GLenum wrapMode, const struct gl_texture_image *img, GLint size, GLfloat s, GLint *i0, GLint *i1, GLfloat *weight) { const struct swrast_texture_image *swImg = swrast_texture_image_const(img); GLfloat u; switch (wrapMode) { case GL_REPEAT: u = s * size - 0.5F; if (swImg->_IsPowerOfTwo) { *i0 = IFLOOR(u) & (size - 1); *i1 = (*i0 + 1) & (size - 1); } else { *i0 = REMAINDER(IFLOOR(u), size); *i1 = REMAINDER(*i0 + 1, size); } break; case GL_MIRRORED_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 GL_CLAMP: 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; default: _mesa_problem(NULL, "Bad wrap mode"); u = 0.0F; break; } *weight = FRAC(u); } /** * Used to compute texel location for nearest sampling. */ static inline GLint nearest_texel_location(GLenum wrapMode, const struct gl_texture_image *img, GLint size, GLfloat s) { const struct swrast_texture_image *swImg = swrast_texture_image_const(img); GLint i; switch (wrapMode) { case GL_REPEAT: /* s limited to [0,1) */ /* i limited to [0,size-1] */ i = IFLOOR(s * size); if (swImg->_IsPowerOfTwo) i &= (size - 1); else i = REMAINDER(i, size); return i; case GL_MIRRORED_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 GL_CLAMP: /* 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; default: _mesa_problem(NULL, "Bad wrap mode"); return 0; } } /* Power of two image sizes only */ static inline void linear_repeat_texel_location(GLuint size, GLfloat s, GLint *i0, GLint *i1, GLfloat *weight) { GLfloat u = s * size - 0.5F; *i0 = IFLOOR(u) & (size - 1); *i1 = (*i0 + 1) & (size - 1); *weight = FRAC(u); } /** * For linear interpolation between mipmap levels N and N+1, this function * computes N. */ static inline GLint linear_mipmap_level(const struct gl_texture_object *tObj, GLfloat lambda) { if (lambda < 0.0F) return tObj->BaseLevel; else if (lambda > tObj->_MaxLambda) return (GLint) (tObj->BaseLevel + tObj->_MaxLambda); else return (GLint) (tObj->BaseLevel + lambda); } /** * Compute the nearest mipmap level to take texels from. */ static inline GLint nearest_mipmap_level(const struct gl_texture_object *tObj, GLfloat lambda) { GLfloat l; GLint level; if (lambda <= 0.5F) l = 0.0F; else if (lambda > tObj->_MaxLambda + 0.4999F) l = tObj->_MaxLambda + 0.4999F; else l = lambda; level = (GLint) (tObj->BaseLevel + l + 0.5F); if (level > tObj->_MaxLevel) level = tObj->_MaxLevel; return level; } /* * Bitflags for texture border color sampling. */ #define I0BIT 1 #define I1BIT 2 #define J0BIT 4 #define J1BIT 8 #define K0BIT 16 #define K1BIT 32 /** * The lambda[] array values are always monotonic. Either the whole span * will be minified, magnified, or split between the two. This function * determines the subranges in [0, n-1] that are to be minified or magnified. */ static inline void compute_min_mag_ranges(const struct gl_texture_object *tObj, GLuint n, const GLfloat lambda[], GLuint *minStart, GLuint *minEnd, GLuint *magStart, GLuint *magEnd) { GLfloat minMagThresh; /* we shouldn't be here if minfilter == magfilter */ ASSERT(tObj->Sampler.MinFilter != tObj->Sampler.MagFilter); /* This bit comes from the OpenGL spec: */ if (tObj->Sampler.MagFilter == GL_LINEAR && (tObj->Sampler.MinFilter == GL_NEAREST_MIPMAP_NEAREST || tObj->Sampler.MinFilter == GL_NEAREST_MIPMAP_LINEAR)) { minMagThresh = 0.5F; } else { minMagThresh = 0.0F; } #if 0 /* DEBUG CODE: Verify that lambda[] is monotonic. * We can't really use this because the inaccuracy in the LOG2 function * causes this test to fail, yet the resulting texturing is correct. */ if (n > 1) { GLuint i; printf("lambda delta = %g\n", lambda[0] - lambda[n-1]); if (lambda[0] >= lambda[n-1]) { /* decreasing */ for (i = 0; i < n - 1; i++) { ASSERT((GLint) (lambda[i] * 10) >= (GLint) (lambda[i+1] * 10)); } } else { /* increasing */ for (i = 0; i < n - 1; i++) { ASSERT((GLint) (lambda[i] * 10) <= (GLint) (lambda[i+1] * 10)); } } } #endif /* DEBUG */ if (lambda[0] <= minMagThresh && (n <= 1 || lambda[n-1] <= minMagThresh)) { /* magnification for whole span */ *magStart = 0; *magEnd = n; *minStart = *minEnd = 0; } else if (lambda[0] > minMagThresh && (n <=1 || lambda[n-1] > minMagThresh)) { /* minification for whole span */ *minStart = 0; *minEnd = n; *magStart = *magEnd = 0; } else { /* a mix of minification and magnification */ GLuint i; if (lambda[0] > minMagThresh) { /* start with minification */ for (i = 1; i < n; i++) { if (lambda[i] <= minMagThresh) break; } *minStart = 0; *minEnd = i; *magStart = i; *magEnd = n; } else { /* start with magnification */ for (i = 1; i < n; i++) { if (lambda[i] > minMagThresh) break; } *magStart = 0; *magEnd = i; *minStart = i; *minEnd = n; } } #if 0 /* Verify the min/mag Start/End values * We don't use this either (see above) */ { GLint i; for (i = 0; i < n; i++) { if (lambda[i] > minMagThresh) { /* minification */ ASSERT(i >= *minStart); ASSERT(i < *minEnd); } else { /* magnification */ ASSERT(i >= *magStart); ASSERT(i < *magEnd); } } } #endif } /** * When we sample the border color, it must be interpreted according to * the base texture format. Ex: if the texture base format it GL_ALPHA, * we return (0,0,0,BorderAlpha). */ static inline void get_border_color(const struct gl_texture_object *tObj, const struct gl_texture_image *img, GLfloat rgba[4]) { switch (img->_BaseFormat) { case GL_RGB: rgba[0] = tObj->Sampler.BorderColor.f[0]; rgba[1] = tObj->Sampler.BorderColor.f[1]; rgba[2] = tObj->Sampler.BorderColor.f[2]; rgba[3] = 1.0F; break; case GL_ALPHA: rgba[0] = rgba[1] = rgba[2] = 0.0; rgba[3] = tObj->Sampler.BorderColor.f[3]; break; case GL_LUMINANCE: rgba[0] = rgba[1] = rgba[2] = tObj->Sampler.BorderColor.f[0]; rgba[3] = 1.0; break; case GL_LUMINANCE_ALPHA: rgba[0] = rgba[1] = rgba[2] = tObj->Sampler.BorderColor.f[0]; rgba[3] = tObj->Sampler.BorderColor.f[3]; break; case GL_INTENSITY: rgba[0] = rgba[1] = rgba[2] = rgba[3] = tObj->Sampler.BorderColor.f[0]; break; default: COPY_4V(rgba, tObj->Sampler.BorderColor.f); break; } } /**********************************************************************/ /* 1-D Texture Sampling Functions */ /**********************************************************************/ /** * Return the texture sample for coordinate (s) using GL_NEAREST filter. */ static inline void sample_1d_nearest(struct gl_context *ctx, const struct gl_texture_object *tObj, const struct gl_texture_image *img, const GLfloat texcoord[4], GLfloat rgba[4]) { const struct swrast_texture_image *swImg = swrast_texture_image_const(img); const GLint width = img->Width2; /* without border, power of two */ GLint i; i = nearest_texel_location(tObj->Sampler.WrapS, img, width, texcoord[0]); /* skip over the border, if any */ i += img->Border; if (i < 0 || i >= (GLint) img->Width) { /* Need this test for GL_CLAMP_TO_BORDER mode */ get_border_color(tObj, img, rgba); } else { swImg->FetchTexel(swImg, i, 0, 0, rgba); } } /** * Return the texture sample for coordinate (s) using GL_LINEAR filter. */ static inline void sample_1d_linear(struct gl_context *ctx, const struct gl_texture_object *tObj, const struct gl_texture_image *img, const GLfloat texcoord[4], GLfloat rgba[4]) { const struct swrast_texture_image *swImg = swrast_texture_image_const(img); const GLint width = img->Width2; GLint i0, i1; GLbitfield useBorderColor = 0x0; GLfloat a; GLfloat t0[4], t1[4]; /* texels */ linear_texel_locations(tObj->Sampler.WrapS, img, width, texcoord[0], &i0, &i1, &a); if (img->Border) { i0 += img->Border; i1 += img->Border; } else { if (i0 < 0 || i0 >= width) useBorderColor |= I0BIT; if (i1 < 0 || i1 >= width) useBorderColor |= I1BIT; } /* fetch texel colors */ if (useBorderColor & I0BIT) { get_border_color(tObj, img, t0); } else { swImg->FetchTexel(swImg, i0, 0, 0, t0); } if (useBorderColor & I1BIT) { get_border_color(tObj, img, t1); } else { swImg->FetchTexel(swImg, i1, 0, 0, t1); } lerp_rgba(rgba, a, t0, t1); } static void sample_1d_nearest_mipmap_nearest(struct gl_context *ctx, const struct gl_texture_object *tObj, GLuint n, const GLfloat texcoord[][4], const GLfloat lambda[], GLfloat rgba[][4]) { GLuint i; ASSERT(lambda != NULL); for (i = 0; i < n; i++) { GLint level = nearest_mipmap_level(tObj, lambda[i]); sample_1d_nearest(ctx, tObj, tObj->Image[0][level], texcoord[i], rgba[i]); } } static void sample_1d_linear_mipmap_nearest(struct gl_context *ctx, const struct gl_texture_object *tObj, GLuint n, const GLfloat texcoord[][4], const GLfloat lambda[], GLfloat rgba[][4]) { GLuint i; ASSERT(lambda != NULL); for (i = 0; i < n; i++) { GLint level = nearest_mipmap_level(tObj, lambda[i]); sample_1d_linear(ctx, tObj, tObj->Image[0][level], texcoord[i], rgba[i]); } } static void sample_1d_nearest_mipmap_linear(struct gl_context *ctx, const struct gl_texture_object *tObj, GLuint n, const GLfloat texcoord[][4], const GLfloat lambda[], GLfloat rgba[][4]) { GLuint i; ASSERT(lambda != NULL); for (i = 0; i < n; i++) { GLint level = linear_mipmap_level(tObj, lambda[i]); if (level >= tObj->_MaxLevel) { sample_1d_nearest(ctx, tObj, tObj->Image[0][tObj->_MaxLevel], texcoord[i], rgba[i]); } else { GLfloat t0[4], t1[4]; const GLfloat f = FRAC(lambda[i]); sample_1d_nearest(ctx, tObj, tObj->Image[0][level ], texcoord[i], t0); sample_1d_nearest(ctx, tObj, tObj->Image[0][level+1], texcoord[i], t1); lerp_rgba(rgba[i], f, t0, t1); } } } static void sample_1d_linear_mipmap_linear(struct gl_context *ctx, const struct gl_texture_object *tObj, GLuint n, const GLfloat texcoord[][4], const GLfloat lambda[], GLfloat rgba[][4]) { GLuint i; ASSERT(lambda != NULL); for (i = 0; i < n; i++) { GLint level = linear_mipmap_level(tObj, lambda[i]); if (level >= tObj->_MaxLevel) { sample_1d_linear(ctx, tObj, tObj->Image[0][tObj->_MaxLevel], texcoord[i], rgba[i]); } else { GLfloat t0[4], t1[4]; const GLfloat f = FRAC(lambda[i]); sample_1d_linear(ctx, tObj, tObj->Image[0][level ], texcoord[i], t0); sample_1d_linear(ctx, tObj, tObj->Image[0][level+1], texcoord[i], t1); lerp_rgba(rgba[i], f, t0, t1); } } } /** Sample 1D texture, nearest filtering for both min/magnification */ static void sample_nearest_1d( struct gl_context *ctx, const struct gl_texture_object *tObj, GLuint n, const GLfloat texcoords[][4], const GLfloat lambda[], GLfloat rgba[][4] ) { GLuint i; struct gl_texture_image *image = tObj->Image[0][tObj->BaseLevel]; (void) lambda; for (i = 0; i < n; i++) { sample_1d_nearest(ctx, tObj, image, texcoords[i], rgba[i]); } } /** Sample 1D texture, linear filtering for both min/magnification */ static void sample_linear_1d( struct gl_context *ctx, const struct gl_texture_object *tObj, GLuint n, const GLfloat texcoords[][4], const GLfloat lambda[], GLfloat rgba[][4] ) { GLuint i; struct gl_texture_image *image = tObj->Image[0][tObj->BaseLevel]; (void) lambda; for (i = 0; i < n; i++) { sample_1d_linear(ctx, tObj, image, texcoords[i], rgba[i]); } } /** Sample 1D texture, using lambda to choose between min/magnification */ static void sample_lambda_1d( struct gl_context *ctx, const struct gl_texture_object *tObj, GLuint n, const GLfloat texcoords[][4], const GLfloat lambda[], GLfloat rgba[][4] ) { GLuint minStart, minEnd; /* texels with minification */ GLuint magStart, magEnd; /* texels with magnification */ GLuint i; ASSERT(lambda != NULL); compute_min_mag_ranges(tObj, n, lambda, &minStart, &minEnd, &magStart, &magEnd); if (minStart < minEnd) { /* do the minified texels */ const GLuint m = minEnd - minStart; switch (tObj->Sampler.MinFilter) { case GL_NEAREST: for (i = minStart; i < minEnd; i++) sample_1d_nearest(ctx, tObj, tObj->Image[0][tObj->BaseLevel], texcoords[i], rgba[i]); break; case GL_LINEAR: for (i = minStart; i < minEnd; i++) sample_1d_linear(ctx, tObj, tObj->Image[0][tObj->BaseLevel], texcoords[i], rgba[i]); break; case GL_NEAREST_MIPMAP_NEAREST: sample_1d_nearest_mipmap_nearest(ctx, tObj, m, texcoords + minStart, lambda + minStart, rgba + minStart); break; case GL_LINEAR_MIPMAP_NEAREST: sample_1d_linear_mipmap_nearest(ctx, tObj, m, texcoords + minStart, lambda + minStart, rgba + minStart); break; case GL_NEAREST_MIPMAP_LINEAR: sample_1d_nearest_mipmap_linear(ctx, tObj, m, texcoords + minStart, lambda + minStart, rgba + minStart); break; case GL_LINEAR_MIPMAP_LINEAR: sample_1d_linear_mipmap_linear(ctx, tObj, m, texcoords + minStart, lambda + minStart, rgba + minStart); break; default: _mesa_problem(ctx, "Bad min filter in sample_1d_texture"); return; } } if (magStart < magEnd) { /* do the magnified texels */ switch (tObj->Sampler.MagFilter) { case GL_NEAREST: for (i = magStart; i < magEnd; i++) sample_1d_nearest(ctx, tObj, tObj->Image[0][tObj->BaseLevel], texcoords[i], rgba[i]); break; case GL_LINEAR: for (i = magStart; i < magEnd; i++) sample_1d_linear(ctx, tObj, tObj->Image[0][tObj->BaseLevel], texcoords[i], rgba[i]); break; default: _mesa_problem(ctx, "Bad mag filter in sample_1d_texture"); return; } } } /**********************************************************************/ /* 2-D Texture Sampling Functions */ /**********************************************************************/ /** * Return the texture sample for coordinate (s,t) using GL_NEAREST filter. */ static inline void sample_2d_nearest(struct gl_context *ctx, const struct gl_texture_object *tObj, const struct gl_texture_image *img, const GLfloat texcoord[4], GLfloat rgba[]) { const struct swrast_texture_image *swImg = swrast_texture_image_const(img); const GLint width = img->Width2; /* without border, power of two */ const GLint height = img->Height2; /* without border, power of two */ GLint i, j; (void) ctx; i = nearest_texel_location(tObj->Sampler.WrapS, img, width, texcoord[0]); j = nearest_texel_location(tObj->Sampler.WrapT, img, height, texcoord[1]); /* skip over the border, if any */ i += img->Border; j += img->Border; if (i < 0 || i >= (GLint) img->Width || j < 0 || j >= (GLint) img->Height) { /* Need this test for GL_CLAMP_TO_BORDER mode */ get_border_color(tObj, img, rgba); } else { swImg->FetchTexel(swImg, i, j, 0, rgba); } } /** * Return the texture sample for coordinate (s,t) using GL_LINEAR filter. * New sampling code contributed by Lynn Quam . */ static inline void sample_2d_linear(struct gl_context *ctx, const struct gl_texture_object *tObj, const struct gl_texture_image *img, const GLfloat texcoord[4], GLfloat rgba[]) { const struct swrast_texture_image *swImg = swrast_texture_image_const(img); const GLint width = img->Width2; const GLint height = img->Height2; GLint i0, j0, i1, j1; GLbitfield useBorderColor = 0x0; GLfloat a, b; GLfloat t00[4], t10[4], t01[4], t11[4]; /* sampled texel colors */ linear_texel_locations(tObj->Sampler.WrapS, img, width, texcoord[0], &i0, &i1, &a); linear_texel_locations(tObj->Sampler.WrapT, img, height, texcoord[1], &j0, &j1, &b); if (img->Border) { i0 += img->Border; i1 += img->Border; j0 += img->Border; j1 += img->Border; } else { if (i0 < 0 || i0 >= width) useBorderColor |= I0BIT; if (i1 < 0 || i1 >= width) useBorderColor |= I1BIT; if (j0 < 0 || j0 >= height) useBorderColor |= J0BIT; if (j1 < 0 || j1 >= height) useBorderColor |= J1BIT; } /* fetch four texel colors */ if (useBorderColor & (I0BIT | J0BIT)) { get_border_color(tObj, img, t00); } else { swImg->FetchTexel(swImg, i0, j0, 0, t00); } if (useBorderColor & (I1BIT | J0BIT)) { get_border_color(tObj, img, t10); } else { swImg->FetchTexel(swImg, i1, j0, 0, t10); } if (useBorderColor & (I0BIT | J1BIT)) { get_border_color(tObj, img, t01); } else { swImg->FetchTexel(swImg, i0, j1, 0, t01); } if (useBorderColor & (I1BIT | J1BIT)) { get_border_color(tObj, img, t11); } else { swImg->FetchTexel(swImg, i1, j1, 0, t11); } lerp_rgba_2d(rgba, a, b, t00, t10, t01, t11); } /** * As above, but we know WRAP_S == REPEAT and WRAP_T == REPEAT. * We don't have to worry about the texture border. */ static inline void sample_2d_linear_repeat(struct gl_context *ctx, const struct gl_texture_object *tObj, const struct gl_texture_image *img, const GLfloat texcoord[4], GLfloat rgba[]) { const struct swrast_texture_image *swImg = swrast_texture_image_const(img); const GLint width = img->Width2; const GLint height = img->Height2; GLint i0, j0, i1, j1; GLfloat wi, wj; GLfloat t00[4], t10[4], t01[4], t11[4]; /* sampled texel colors */ (void) ctx; ASSERT(tObj->Sampler.WrapS == GL_REPEAT); ASSERT(tObj->Sampler.WrapT == GL_REPEAT); ASSERT(img->Border == 0); ASSERT(swImg->_IsPowerOfTwo); linear_repeat_texel_location(width, texcoord[0], &i0, &i1, &wi); linear_repeat_texel_location(height, texcoord[1], &j0, &j1, &wj); swImg->FetchTexel(swImg, i0, j0, 0, t00); swImg->FetchTexel(swImg, i1, j0, 0, t10); swImg->FetchTexel(swImg, i0, j1, 0, t01); swImg->FetchTexel(swImg, i1, j1, 0, t11); lerp_rgba_2d(rgba, wi, wj, t00, t10, t01, t11); } static void sample_2d_nearest_mipmap_nearest(struct gl_context *ctx, const struct gl_texture_object *tObj, GLuint n, const GLfloat texcoord[][4], const GLfloat lambda[], GLfloat rgba[][4]) { GLuint i; for (i = 0; i < n; i++) { GLint level = nearest_mipmap_level(tObj, lambda[i]); sample_2d_nearest(ctx, tObj, tObj->Image[0][level], texcoord[i], rgba[i]); } } static void sample_2d_linear_mipmap_nearest(struct gl_context *ctx, const struct gl_texture_object *tObj, GLuint n, const GLfloat texcoord[][4], const GLfloat lambda[], GLfloat rgba[][4]) { GLuint i; ASSERT(lambda != NULL); for (i = 0; i < n; i++) { GLint level = nearest_mipmap_level(tObj, lambda[i]); sample_2d_linear(ctx, tObj, tObj->Image[0][level], texcoord[i], rgba[i]); } } static void sample_2d_nearest_mipmap_linear(struct gl_context *ctx, const struct gl_texture_object *tObj, GLuint n, const GLfloat texcoord[][4], const GLfloat lambda[], GLfloat rgba[][4]) { GLuint i; ASSERT(lambda != NULL); for (i = 0; i < n; i++) { GLint level = linear_mipmap_level(tObj, lambda[i]); if (level >= tObj->_MaxLevel) { sample_2d_nearest(ctx, tObj, tObj->Image[0][tObj->_MaxLevel], texcoord[i], rgba[i]); } else { GLfloat t0[4], t1[4]; /* texels */ const GLfloat f = FRAC(lambda[i]); sample_2d_nearest(ctx, tObj, tObj->Image[0][level ], texcoord[i], t0); sample_2d_nearest(ctx, tObj, tObj->Image[0][level+1], texcoord[i], t1); lerp_rgba(rgba[i], f, t0, t1); } } } static void sample_2d_linear_mipmap_linear( struct gl_context *ctx, const struct gl_texture_object *tObj, GLuint n, const GLfloat texcoord[][4], const GLfloat lambda[], GLfloat rgba[][4] ) { GLuint i; ASSERT(lambda != NULL); for (i = 0; i < n; i++) { GLint level = linear_mipmap_level(tObj, lambda[i]); if (level >= tObj->_MaxLevel) { sample_2d_linear(ctx, tObj, tObj->Image[0][tObj->_MaxLevel], texcoord[i], rgba[i]); } else { GLfloat t0[4], t1[4]; /* texels */ const GLfloat f = FRAC(lambda[i]); sample_2d_linear(ctx, tObj, tObj->Image[0][level ], texcoord[i], t0); sample_2d_linear(ctx, tObj, tObj->Image[0][level+1], texcoord[i], t1); lerp_rgba(rgba[i], f, t0, t1); } } } static void sample_2d_linear_mipmap_linear_repeat(struct gl_context *ctx, const struct gl_texture_object *tObj, GLuint n, const GLfloat texcoord[][4], const GLfloat lambda[], GLfloat rgba[][4]) { GLuint i; ASSERT(lambda != NULL); ASSERT(tObj->Sampler.WrapS == GL_REPEAT); ASSERT(tObj->Sampler.WrapT == GL_REPEAT); for (i = 0; i < n; i++) { GLint level = linear_mipmap_level(tObj, lambda[i]); if (level >= tObj->_MaxLevel) { sample_2d_linear_repeat(ctx, tObj, tObj->Image[0][tObj->_MaxLevel], texcoord[i], rgba[i]); } else { GLfloat t0[4], t1[4]; /* texels */ const GLfloat f = FRAC(lambda[i]); sample_2d_linear_repeat(ctx, tObj, tObj->Image[0][level ], texcoord[i], t0); sample_2d_linear_repeat(ctx, tObj, tObj->Image[0][level+1], texcoord[i], t1); lerp_rgba(rgba[i], f, t0, t1); } } } /** Sample 2D texture, nearest filtering for both min/magnification */ static void sample_nearest_2d(struct gl_context *ctx, const struct gl_texture_object *tObj, GLuint n, const GLfloat texcoords[][4], const GLfloat lambda[], GLfloat rgba[][4]) { GLuint i; struct gl_texture_image *image = tObj->Image[0][tObj->BaseLevel]; (void) lambda; for (i = 0; i < n; i++) { sample_2d_nearest(ctx, tObj, image, texcoords[i], rgba[i]); } } /** Sample 2D texture, linear filtering for both min/magnification */ static void sample_linear_2d(struct gl_context *ctx, const struct gl_texture_object *tObj, GLuint n, const GLfloat texcoords[][4], const GLfloat lambda[], GLfloat rgba[][4]) { GLuint i; struct gl_texture_image *image = tObj->Image[0][tObj->BaseLevel]; const struct swrast_texture_image *swImg = swrast_texture_image_const(image); (void) lambda; if (tObj->Sampler.WrapS == GL_REPEAT && tObj->Sampler.WrapT == GL_REPEAT && swImg->_IsPowerOfTwo && image->Border == 0) { for (i = 0; i < n; i++) { sample_2d_linear_repeat(ctx, tObj, image, texcoords[i], rgba[i]); } } else { for (i = 0; i < n; i++) { sample_2d_linear(ctx, tObj, image, texcoords[i], rgba[i]); } } } /** * Optimized 2-D texture sampling: * S and T wrap mode == GL_REPEAT * GL_NEAREST min/mag filter * No border, * RowStride == Width, * Format = GL_RGB */ static void opt_sample_rgb_2d(struct gl_context *ctx, const struct gl_texture_object *tObj, GLuint n, const GLfloat texcoords[][4], const GLfloat lambda[], GLfloat rgba[][4]) { const struct gl_texture_image *img = tObj->Image[0][tObj->BaseLevel]; const struct swrast_texture_image *swImg = swrast_texture_image_const(img); const GLfloat width = (GLfloat) img->Width; const GLfloat height = (GLfloat) img->Height; const GLint colMask = img->Width - 1; const GLint rowMask = img->Height - 1; const GLint shift = img->WidthLog2; GLuint k; (void) ctx; (void) lambda; ASSERT(tObj->Sampler.WrapS==GL_REPEAT); ASSERT(tObj->Sampler.WrapT==GL_REPEAT); ASSERT(img->Border==0); ASSERT(img->TexFormat == MESA_FORMAT_RGB888); ASSERT(swImg->_IsPowerOfTwo); (void) swImg; for (k=0; kMap + 3 * pos; rgba[k][RCOMP] = UBYTE_TO_FLOAT(texel[2]); rgba[k][GCOMP] = UBYTE_TO_FLOAT(texel[1]); rgba[k][BCOMP] = UBYTE_TO_FLOAT(texel[0]); rgba[k][ACOMP] = 1.0F; } } /** * Optimized 2-D texture sampling: * S and T wrap mode == GL_REPEAT * GL_NEAREST min/mag filter * No border * RowStride == Width, * Format = GL_RGBA */ static void opt_sample_rgba_2d(struct gl_context *ctx, const struct gl_texture_object *tObj, GLuint n, const GLfloat texcoords[][4], const GLfloat lambda[], GLfloat rgba[][4]) { const struct gl_texture_image *img = tObj->Image[0][tObj->BaseLevel]; const struct swrast_texture_image *swImg = swrast_texture_image_const(img); const GLfloat width = (GLfloat) img->Width; const GLfloat height = (GLfloat) img->Height; const GLint colMask = img->Width - 1; const GLint rowMask = img->Height - 1; const GLint shift = img->WidthLog2; GLuint i; (void) ctx; (void) lambda; ASSERT(tObj->Sampler.WrapS==GL_REPEAT); ASSERT(tObj->Sampler.WrapT==GL_REPEAT); ASSERT(img->Border==0); ASSERT(img->TexFormat == MESA_FORMAT_RGBA8888); ASSERT(swImg->_IsPowerOfTwo); (void) swImg; for (i = 0; i < n; i++) { const GLint col = IFLOOR(texcoords[i][0] * width) & colMask; const GLint row = IFLOOR(texcoords[i][1] * height) & rowMask; const GLint pos = (row << shift) | col; const GLuint texel = *((GLuint *) swImg->Map + pos); rgba[i][RCOMP] = UBYTE_TO_FLOAT( (texel >> 24) ); rgba[i][GCOMP] = UBYTE_TO_FLOAT( (texel >> 16) & 0xff ); rgba[i][BCOMP] = UBYTE_TO_FLOAT( (texel >> 8) & 0xff ); rgba[i][ACOMP] = UBYTE_TO_FLOAT( (texel ) & 0xff ); } } /** Sample 2D texture, using lambda to choose between min/magnification */ static void sample_lambda_2d(struct gl_context *ctx, const struct gl_texture_object *tObj, GLuint n, const GLfloat texcoords[][4], const GLfloat lambda[], GLfloat rgba[][4]) { const struct gl_texture_image *tImg = tObj->Image[0][tObj->BaseLevel]; const struct swrast_texture_image *swImg = swrast_texture_image_const(tImg); GLuint minStart, minEnd; /* texels with minification */ GLuint magStart, magEnd; /* texels with magnification */ const GLboolean repeatNoBorderPOT = (tObj->Sampler.WrapS == GL_REPEAT) && (tObj->Sampler.WrapT == GL_REPEAT) && (tImg->Border == 0 && (tImg->Width == swImg->RowStride)) && swImg->_IsPowerOfTwo; ASSERT(lambda != NULL); compute_min_mag_ranges(tObj, n, lambda, &minStart, &minEnd, &magStart, &magEnd); if (minStart < minEnd) { /* do the minified texels */ const GLuint m = minEnd - minStart; switch (tObj->Sampler.MinFilter) { case GL_NEAREST: if (repeatNoBorderPOT) { switch (tImg->TexFormat) { case MESA_FORMAT_RGB888: opt_sample_rgb_2d(ctx, tObj, m, texcoords + minStart, NULL, rgba + minStart); break; case MESA_FORMAT_RGBA8888: opt_sample_rgba_2d(ctx, tObj, m, texcoords + minStart, NULL, rgba + minStart); break; default: sample_nearest_2d(ctx, tObj, m, texcoords + minStart, NULL, rgba + minStart ); } } else { sample_nearest_2d(ctx, tObj, m, texcoords + minStart, NULL, rgba + minStart); } break; case GL_LINEAR: sample_linear_2d(ctx, tObj, m, texcoords + minStart, NULL, rgba + minStart); break; case GL_NEAREST_MIPMAP_NEAREST: sample_2d_nearest_mipmap_nearest(ctx, tObj, m, texcoords + minStart, lambda + minStart, rgba + minStart); break; case GL_LINEAR_MIPMAP_NEAREST: sample_2d_linear_mipmap_nearest(ctx, tObj, m, texcoords + minStart, lambda + minStart, rgba + minStart); break; case GL_NEAREST_MIPMAP_LINEAR: sample_2d_nearest_mipmap_linear(ctx, tObj, m, texcoords + minStart, lambda + minStart, rgba + minStart); break; case GL_LINEAR_MIPMAP_LINEAR: if (repeatNoBorderPOT) sample_2d_linear_mipmap_linear_repeat(ctx, tObj, m, texcoords + minStart, lambda + minStart, rgba + minStart); else sample_2d_linear_mipmap_linear(ctx, tObj, m, texcoords + minStart, lambda + minStart, rgba + minStart); break; default: _mesa_problem(ctx, "Bad min filter in sample_2d_texture"); return; } } if (magStart < magEnd) { /* do the magnified texels */ const GLuint m = magEnd - magStart; switch (tObj->Sampler.MagFilter) { case GL_NEAREST: if (repeatNoBorderPOT) { switch (tImg->TexFormat) { case MESA_FORMAT_RGB888: opt_sample_rgb_2d(ctx, tObj, m, texcoords + magStart, NULL, rgba + magStart); break; case MESA_FORMAT_RGBA8888: opt_sample_rgba_2d(ctx, tObj, m, texcoords + magStart, NULL, rgba + magStart); break; default: sample_nearest_2d(ctx, tObj, m, texcoords + magStart, NULL, rgba + magStart ); } } else { sample_nearest_2d(ctx, tObj, m, texcoords + magStart, NULL, rgba + magStart); } break; case GL_LINEAR: sample_linear_2d(ctx, tObj, m, texcoords + magStart, NULL, rgba + magStart); break; default: _mesa_problem(ctx, "Bad mag filter in sample_lambda_2d"); break; } } } /* For anisotropic filtering */ #define WEIGHT_LUT_SIZE 1024 static GLfloat *weightLut = NULL; /** * Creates the look-up table used to speed-up EWA sampling */ static void create_filter_table(void) { GLuint i; if (!weightLut) { weightLut = (GLfloat *) malloc(WEIGHT_LUT_SIZE * sizeof(GLfloat)); for (i = 0; i < WEIGHT_LUT_SIZE; ++i) { GLfloat alpha = 2; GLfloat r2 = (GLfloat) i / (GLfloat) (WEIGHT_LUT_SIZE - 1); GLfloat weight = (GLfloat) exp(-alpha * r2); weightLut[i] = weight; } } } /** * Elliptical weighted average (EWA) filter for producing high quality * anisotropic filtered results. * Based on the Higher Quality Elliptical Weighted Avarage Filter * published by Paul S. Heckbert in his Master's Thesis * "Fundamentals of Texture Mapping and Image Warping" (1989) */ static void sample_2d_ewa(struct gl_context *ctx, const struct gl_texture_object *tObj, const GLfloat texcoord[4], const GLfloat dudx, const GLfloat dvdx, const GLfloat dudy, const GLfloat dvdy, const GLint lod, GLfloat rgba[]) { GLint level = lod > 0 ? lod : 0; GLfloat scaling = 1.0 / (1 << level); const struct gl_texture_image *img = tObj->Image[0][level]; const struct gl_texture_image *mostDetailedImage = tObj->Image[0][tObj->BaseLevel]; const struct swrast_texture_image *swImg = swrast_texture_image_const(mostDetailedImage); GLfloat tex_u=-0.5 + texcoord[0] * swImg->WidthScale * scaling; GLfloat tex_v=-0.5 + texcoord[1] * swImg->HeightScale * scaling; GLfloat ux = dudx * scaling; GLfloat vx = dvdx * scaling; GLfloat uy = dudy * scaling; GLfloat vy = dvdy * scaling; /* compute ellipse coefficients to bound the region: * A*x*x + B*x*y + C*y*y = F. */ GLfloat A = vx*vx+vy*vy+1; GLfloat B = -2*(ux*vx+uy*vy); GLfloat C = ux*ux+uy*uy+1; GLfloat F = A*C-B*B/4.0; /* check if it is an ellipse */ /* ASSERT(F > 0.0); */ /* Compute the ellipse's (u,v) bounding box in texture space */ GLfloat d = -B*B+4.0*C*A; GLfloat box_u = 2.0 / d * sqrt(d*C*F); /* box_u -> half of bbox with */ GLfloat box_v = 2.0 / d * sqrt(A*d*F); /* box_v -> half of bbox height */ GLint u0 = floor(tex_u - box_u); GLint u1 = ceil (tex_u + box_u); GLint v0 = floor(tex_v - box_v); GLint v1 = ceil (tex_v + box_v); GLfloat num[4] = {0.0F, 0.0F, 0.0F, 0.0F}; GLfloat newCoord[2]; GLfloat den = 0.0F; GLfloat ddq; GLfloat U = u0 - tex_u; GLint v; /* Scale ellipse formula to directly index the Filter Lookup Table. * i.e. scale so that F = WEIGHT_LUT_SIZE-1 */ double formScale = (double) (WEIGHT_LUT_SIZE - 1) / F; A *= formScale; B *= formScale; C *= formScale; /* F *= formScale; */ /* no need to scale F as we don't use it below here */ /* Heckbert MS thesis, p. 59; scan over the bounding box of the ellipse * and incrementally update the value of Ax^2+Bxy*Cy^2; when this * value, q, is less than F, we're inside the ellipse */ ddq = 2 * A; for (v = v0; v <= v1; ++v) { GLfloat V = v - tex_v; GLfloat dq = A * (2 * U + 1) + B * V; GLfloat q = (C * V + B * U) * V + A * U * U; GLint u; for (u = u0; u <= u1; ++u) { /* Note that the ellipse has been pre-scaled so F = WEIGHT_LUT_SIZE - 1 */ if (q < WEIGHT_LUT_SIZE) { /* as a LUT is used, q must never be negative; * should not happen, though */ const GLint qClamped = q >= 0.0F ? q : 0; GLfloat weight = weightLut[qClamped]; newCoord[0] = u / ((GLfloat) img->Width2); newCoord[1] = v / ((GLfloat) img->Height2); sample_2d_nearest(ctx, tObj, img, newCoord, rgba); num[0] += weight * rgba[0]; num[1] += weight * rgba[1]; num[2] += weight * rgba[2]; num[3] += weight * rgba[3]; den += weight; } q += dq; dq += ddq; } } if (den <= 0.0F) { /* Reaching this place would mean * that no pixels intersected the ellipse. * This should never happen because * the filter we use always * intersects at least one pixel. */ /*rgba[0]=0; rgba[1]=0; rgba[2]=0; rgba[3]=0;*/ /* not enough pixels in resampling, resort to direct interpolation */ sample_2d_linear(ctx, tObj, img, texcoord, rgba); return; } rgba[0] = num[0] / den; rgba[1] = num[1] / den; rgba[2] = num[2] / den; rgba[3] = num[3] / den; } /** * Anisotropic filtering using footprint assembly as outlined in the * EXT_texture_filter_anisotropic spec: * http://www.opengl.org/registry/specs/EXT/texture_filter_anisotropic.txt * Faster than EWA but has less quality (more aliasing effects) */ static void sample_2d_footprint(struct gl_context *ctx, const struct gl_texture_object *tObj, const GLfloat texcoord[4], const GLfloat dudx, const GLfloat dvdx, const GLfloat dudy, const GLfloat dvdy, const GLint lod, GLfloat rgba[]) { GLint level = lod > 0 ? lod : 0; GLfloat scaling = 1.0F / (1 << level); const struct gl_texture_image *img = tObj->Image[0][level]; GLfloat ux = dudx * scaling; GLfloat vx = dvdx * scaling; GLfloat uy = dudy * scaling; GLfloat vy = dvdy * scaling; GLfloat Px2 = ux * ux + vx * vx; /* squared length of dx */ GLfloat Py2 = uy * uy + vy * vy; /* squared length of dy */ GLint numSamples; GLfloat ds; GLfloat dt; GLfloat num[4] = {0.0F, 0.0F, 0.0F, 0.0F}; GLfloat newCoord[2]; GLint s; /* Calculate the per anisotropic sample offsets in s,t space. */ if (Px2 > Py2) { numSamples = ceil(SQRTF(Px2)); ds = ux / ((GLfloat) img->Width2); dt = vx / ((GLfloat) img->Height2); } else { numSamples = ceil(SQRTF(Py2)); ds = uy / ((GLfloat) img->Width2); dt = vy / ((GLfloat) img->Height2); } for (s = 0; sImage[0][tObj->BaseLevel]; const struct swrast_texture_image *swImg = swrast_texture_image_const(tImg); const GLfloat maxEccentricity = tObj->Sampler.MaxAnisotropy * tObj->Sampler.MaxAnisotropy; /* re-calculate the lambda values so that they are usable with anisotropic * filtering */ SWspan *span = (SWspan *)lambda_iso; /* access the "hidden" SWspan struct */ /* based on interpolate_texcoords(struct gl_context *ctx, SWspan *span) * in swrast/s_span.c */ /* find the texture unit index by looking up the current texture object * from the context list of available texture objects. */ const GLuint attr = FRAG_ATTRIB_TEX; GLfloat texW, texH; const GLfloat dsdx = span->attrStepX[attr][0]; const GLfloat dsdy = span->attrStepY[attr][0]; const GLfloat dtdx = span->attrStepX[attr][1]; const GLfloat dtdy = span->attrStepY[attr][1]; const GLfloat dqdx = span->attrStepX[attr][3]; const GLfloat dqdy = span->attrStepY[attr][3]; GLfloat s = span->attrStart[attr][0] + span->leftClip * dsdx; GLfloat t = span->attrStart[attr][1] + span->leftClip * dtdx; GLfloat q = span->attrStart[attr][3] + span->leftClip * dqdx; GLuint i; /* on first access create the lookup table containing the filter weights. */ if (!weightLut) { create_filter_table(); } texW = swImg->WidthScale; texH = swImg->HeightScale; for (i = 0; i < n; i++) { const GLfloat invQ = (q == 0.0F) ? 1.0F : (1.0F / q); GLfloat dudx = texW * ((s + dsdx) / (q + dqdx) - s * invQ); GLfloat dvdx = texH * ((t + dtdx) / (q + dqdx) - t * invQ); GLfloat dudy = texW * ((s + dsdy) / (q + dqdy) - s * invQ); GLfloat dvdy = texH * ((t + dtdy) / (q + dqdy) - t * invQ); /* note: instead of working with Px and Py, we will use the * squared length instead, to avoid sqrt. */ GLfloat Px2 = dudx * dudx + dvdx * dvdx; GLfloat Py2 = dudy * dudy + dvdy * dvdy; GLfloat Pmax2; GLfloat Pmin2; GLfloat e; GLfloat lod; s += dsdx; t += dtdx; q += dqdx; if (Px2 < Py2) { Pmax2 = Py2; Pmin2 = Px2; } else { Pmax2 = Px2; Pmin2 = Py2; } /* if the eccentricity of the ellipse is too big, scale up the shorter * of the two vectors to limit the maximum amount of work per pixel */ e = Pmax2 / Pmin2; if (e > maxEccentricity) { /* GLfloat s=e / maxEccentricity; minor[0] *= s; minor[1] *= s; Pmin2 *= s; */ Pmin2 = Pmax2 / maxEccentricity; } /* note: we need to have Pmin=sqrt(Pmin2) here, but we can avoid * this since 0.5*log(x) = log(sqrt(x)) */ lod = 0.5 * LOG2(Pmin2); /* If the ellipse covers the whole image, we can * simply return the average of the whole image. */ if (lod >= tObj->_MaxLevel) { sample_2d_linear(ctx, tObj, tObj->Image[0][tObj->_MaxLevel], texcoords[i], rgba[i]); } else { /* don't bother interpolating between multiple LODs; it doesn't * seem to be worth the extra running time. */ sample_2d_ewa(ctx, tObj, texcoords[i], dudx, dvdx, dudy, dvdy, floor(lod), rgba[i]); /* unused: */ (void) sample_2d_footprint; /* sample_2d_footprint(ctx, tObj, texcoords[i], dudx, dvdx, dudy, dvdy, floor(lod), rgba[i]); */ } } } /**********************************************************************/ /* Texture Cube Map Sampling Functions */ /**********************************************************************/ /** * Choose one of six sides of a texture cube map given the texture * coord (rx,ry,rz). Return pointer to corresponding array of texture * images. */ static const struct gl_texture_image ** choose_cube_face(const struct gl_texture_object *texObj, const GLfloat texcoord[4], GLfloat newCoord[4]) { /* major axis direction target sc tc ma ---------- ------------------------------- --- --- --- +rx TEXTURE_CUBE_MAP_POSITIVE_X_EXT -rz -ry rx -rx TEXTURE_CUBE_MAP_NEGATIVE_X_EXT +rz -ry rx +ry TEXTURE_CUBE_MAP_POSITIVE_Y_EXT +rx +rz ry -ry TEXTURE_CUBE_MAP_NEGATIVE_Y_EXT +rx -rz ry +rz TEXTURE_CUBE_MAP_POSITIVE_Z_EXT +rx -ry rz -rz TEXTURE_CUBE_MAP_NEGATIVE_Z_EXT -rx -ry rz */ const GLfloat rx = texcoord[0]; const GLfloat ry = texcoord[1]; const GLfloat rz = texcoord[2]; const GLfloat arx = FABSF(rx), ary = FABSF(ry), arz = FABSF(rz); GLuint face; GLfloat sc, tc, ma; if (arx >= ary && arx >= arz) { if (rx >= 0.0F) { face = FACE_POS_X; sc = -rz; tc = -ry; ma = arx; } else { face = FACE_NEG_X; sc = rz; tc = -ry; ma = arx; } } else if (ary >= arx && ary >= arz) { if (ry >= 0.0F) { face = FACE_POS_Y; sc = rx; tc = rz; ma = ary; } else { face = FACE_NEG_Y; sc = rx; tc = -rz; ma = ary; } } else { if (rz > 0.0F) { face = FACE_POS_Z; sc = rx; tc = -ry; ma = arz; } else { face = FACE_NEG_Z; sc = -rx; tc = -ry; ma = arz; } } { const float ima = 1.0F / ma; newCoord[0] = ( sc * ima + 1.0F ) * 0.5F; newCoord[1] = ( tc * ima + 1.0F ) * 0.5F; } return (const struct gl_texture_image **) texObj->Image[face]; } static void sample_nearest_cube(struct gl_context *ctx, const struct gl_texture_object *tObj, GLuint n, const GLfloat texcoords[][4], const GLfloat lambda[], GLfloat rgba[][4]) { GLuint i; (void) lambda; for (i = 0; i < n; i++) { const struct gl_texture_image **images; GLfloat newCoord[4]; images = choose_cube_face(tObj, texcoords[i], newCoord); sample_2d_nearest(ctx, tObj, images[tObj->BaseLevel], newCoord, rgba[i]); } } static void sample_linear_cube(struct gl_context *ctx, const struct gl_texture_object *tObj, GLuint n, const GLfloat texcoords[][4], const GLfloat lambda[], GLfloat rgba[][4]) { GLuint i; (void) lambda; for (i = 0; i < n; i++) { const struct gl_texture_image **images; GLfloat newCoord[4]; images = choose_cube_face(tObj, texcoords[i], newCoord); sample_2d_linear(ctx, tObj, images[tObj->BaseLevel], newCoord, rgba[i]); } } static void sample_cube_nearest_mipmap_nearest(struct gl_context *ctx, const struct gl_texture_object *tObj, GLuint n, const GLfloat texcoord[][4], const GLfloat lambda[], GLfloat rgba[][4]) { GLuint i; ASSERT(lambda != NULL); for (i = 0; i < n; i++) { const struct gl_texture_image **images; GLfloat newCoord[4]; GLint level; images = choose_cube_face(tObj, texcoord[i], newCoord); /* XXX we actually need to recompute lambda here based on the newCoords. * But we would need the texcoords of adjacent fragments to compute that * properly, and we don't have those here. * For now, do an approximation: subtracting 1 from the chosen mipmap * level seems to work in some test cases. * The same adjustment is done in the next few functions. */ level = nearest_mipmap_level(tObj, lambda[i]); level = MAX2(level - 1, 0); sample_2d_nearest(ctx, tObj, images[level], newCoord, rgba[i]); } } static void sample_cube_linear_mipmap_nearest(struct gl_context *ctx, const struct gl_texture_object *tObj, GLuint n, const GLfloat texcoord[][4], const GLfloat lambda[], GLfloat rgba[][4]) { GLuint i; ASSERT(lambda != NULL); for (i = 0; i < n; i++) { const struct gl_texture_image **images; GLfloat newCoord[4]; GLint level = nearest_mipmap_level(tObj, lambda[i]); level = MAX2(level - 1, 0); /* see comment above */ images = choose_cube_face(tObj, texcoord[i], newCoord); sample_2d_linear(ctx, tObj, images[level], newCoord, rgba[i]); } } static void sample_cube_nearest_mipmap_linear(struct gl_context *ctx, const struct gl_texture_object *tObj, GLuint n, const GLfloat texcoord[][4], const GLfloat lambda[], GLfloat rgba[][4]) { GLuint i; ASSERT(lambda != NULL); for (i = 0; i < n; i++) { const struct gl_texture_image **images; GLfloat newCoord[4]; GLint level = linear_mipmap_level(tObj, lambda[i]); level = MAX2(level - 1, 0); /* see comment above */ images = choose_cube_face(tObj, texcoord[i], newCoord); if (level >= tObj->_MaxLevel) { sample_2d_nearest(ctx, tObj, images[tObj->_MaxLevel], newCoord, rgba[i]); } else { GLfloat t0[4], t1[4]; /* texels */ const GLfloat f = FRAC(lambda[i]); sample_2d_nearest(ctx, tObj, images[level ], newCoord, t0); sample_2d_nearest(ctx, tObj, images[level+1], newCoord, t1); lerp_rgba(rgba[i], f, t0, t1); } } } static void sample_cube_linear_mipmap_linear(struct gl_context *ctx, const struct gl_texture_object *tObj, GLuint n, const GLfloat texcoord[][4], const GLfloat lambda[], GLfloat rgba[][4]) { GLuint i; ASSERT(lambda != NULL); for (i = 0; i < n; i++) { const struct gl_texture_image **images; GLfloat newCoord[4]; GLint level = linear_mipmap_level(tObj, lambda[i]); level = MAX2(level - 1, 0); /* see comment above */ images = choose_cube_face(tObj, texcoord[i], newCoord); if (level >= tObj->_MaxLevel) { sample_2d_linear(ctx, tObj, images[tObj->_MaxLevel], newCoord, rgba[i]); } else { GLfloat t0[4], t1[4]; const GLfloat f = FRAC(lambda[i]); sample_2d_linear(ctx, tObj, images[level ], newCoord, t0); sample_2d_linear(ctx, tObj, images[level+1], newCoord, t1); lerp_rgba(rgba[i], f, t0, t1); } } } /** Sample cube texture, using lambda to choose between min/magnification */ static void sample_lambda_cube(struct gl_context *ctx, const struct gl_texture_object *tObj, GLuint n, const GLfloat texcoords[][4], const GLfloat lambda[], GLfloat rgba[][4]) { GLuint minStart, minEnd; /* texels with minification */ GLuint magStart, magEnd; /* texels with magnification */ ASSERT(lambda != NULL); compute_min_mag_ranges(tObj, n, lambda, &minStart, &minEnd, &magStart, &magEnd); if (minStart < minEnd) { /* do the minified texels */ const GLuint m = minEnd - minStart; switch (tObj->Sampler.MinFilter) { case GL_NEAREST: sample_nearest_cube(ctx, tObj, m, texcoords + minStart, lambda + minStart, rgba + minStart); break; case GL_LINEAR: sample_linear_cube(ctx, tObj, m, texcoords + minStart, lambda + minStart, rgba + minStart); break; case GL_NEAREST_MIPMAP_NEAREST: sample_cube_nearest_mipmap_nearest(ctx, tObj, m, texcoords + minStart, lambda + minStart, rgba + minStart); break; case GL_LINEAR_MIPMAP_NEAREST: sample_cube_linear_mipmap_nearest(ctx, tObj, m, texcoords + minStart, lambda + minStart, rgba + minStart); break; case GL_NEAREST_MIPMAP_LINEAR: sample_cube_nearest_mipmap_linear(ctx, tObj, m, texcoords + minStart, lambda + minStart, rgba + minStart); break; case GL_LINEAR_MIPMAP_LINEAR: sample_cube_linear_mipmap_linear(ctx, tObj, m, texcoords + minStart, lambda + minStart, rgba + minStart); break; default: _mesa_problem(ctx, "Bad min filter in sample_lambda_cube"); break; } } if (magStart < magEnd) { /* do the magnified texels */ const GLuint m = magEnd - magStart; switch (tObj->Sampler.MagFilter) { case GL_NEAREST: sample_nearest_cube(ctx, tObj, m, texcoords + magStart, lambda + magStart, rgba + magStart); break; case GL_LINEAR: sample_linear_cube(ctx, tObj, m, texcoords + magStart, lambda + magStart, rgba + magStart); break; default: _mesa_problem(ctx, "Bad mag filter in sample_lambda_cube"); break; } } } /** * We use this function when a texture object is in an "incomplete" state. * When a fragment program attempts to sample an incomplete texture we * return black (see issue 23 in GL_ARB_fragment_program spec). * Note: fragment programs don't observe the texture enable/disable flags. */ static void null_sample_func( struct gl_context *ctx, const struct gl_texture_object *tObj, GLuint n, const GLfloat texcoords[][4], const GLfloat lambda[], GLfloat rgba[][4]) { GLuint i; (void) ctx; (void) tObj; (void) texcoords; (void) lambda; for (i = 0; i < n; i++) { rgba[i][RCOMP] = 0; rgba[i][GCOMP] = 0; rgba[i][BCOMP] = 0; rgba[i][ACOMP] = 1.0; } } /** * Choose the texture sampling function for the given texture object. */ texture_sample_func _swrast_choose_texture_sample_func( struct gl_context *ctx, const struct gl_texture_object *t ) { if (!t || !t->_Complete) { return &null_sample_func; } else { const GLboolean needLambda = (GLboolean) (t->Sampler.MinFilter != t->Sampler.MagFilter); switch (t->Target) { case GL_TEXTURE_1D: if (needLambda) { return &sample_lambda_1d; } else if (t->Sampler.MinFilter == GL_LINEAR) { return &sample_linear_1d; } else { ASSERT(t->Sampler.MinFilter == GL_NEAREST); return &sample_nearest_1d; } case GL_TEXTURE_2D: if (needLambda) { /* Anisotropic filtering extension. Activated only if mipmaps are used */ if (t->Sampler.MaxAnisotropy > 1.0 && t->Sampler.MinFilter == GL_LINEAR_MIPMAP_LINEAR) { return &sample_lambda_2d_aniso; } return &sample_lambda_2d; } else if (t->Sampler.MinFilter == GL_LINEAR) { return &sample_linear_2d; } else { /* check for a few optimized cases */ const struct gl_texture_image *img = t->Image[0][t->BaseLevel]; const struct swrast_texture_image *swImg = swrast_texture_image_const(img); texture_sample_func func; ASSERT(t->Sampler.MinFilter == GL_NEAREST); func = &sample_nearest_2d; if (t->Sampler.WrapS == GL_REPEAT && t->Sampler.WrapT == GL_REPEAT && swImg->_IsPowerOfTwo && img->Border == 0) { if (img->TexFormat == MESA_FORMAT_RGB888) func = &opt_sample_rgb_2d; else if (img->TexFormat == MESA_FORMAT_RGBA8888) func = &opt_sample_rgba_2d; } return func; } case GL_TEXTURE_CUBE_MAP: if (needLambda) { return &sample_lambda_cube; } else if (t->Sampler.MinFilter == GL_LINEAR) { return &sample_linear_cube; } else { ASSERT(t->Sampler.MinFilter == GL_NEAREST); return &sample_nearest_cube; } default: _mesa_problem(ctx, "invalid target in _swrast_choose_texture_sample_func"); return &null_sample_func; } } }