/* * This file is part of mpv. * * mpv is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * mpv is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with mpv. If not, see . */ #include #include "video_shaders.h" #include "video.h" #define GLSL(x) gl_sc_add(sc, #x "\n"); #define GLSLF(...) gl_sc_addf(sc, __VA_ARGS__) #define GLSLH(x) gl_sc_hadd(sc, #x "\n"); #define GLSLHF(...) gl_sc_haddf(sc, __VA_ARGS__) // Set up shared/commonly used variables and macros void sampler_prelude(struct gl_shader_cache *sc, int tex_num) { GLSLF("#undef tex\n"); GLSLF("#define tex texture%d\n", tex_num); GLSLF("vec2 pos = texcoord%d;\n", tex_num); GLSLF("vec2 size = texture_size%d;\n", tex_num); GLSLF("vec2 pt = pixel_size%d;\n", tex_num); } static void pass_sample_separated_get_weights(struct gl_shader_cache *sc, struct scaler *scaler) { gl_sc_uniform_tex(sc, "lut", scaler->gl_target, scaler->gl_lut); // Define a new variable to cache the corrected fcoord. GLSLF("float fcoord_lut = LUT_POS(fcoord, %d.0);\n", scaler->lut_size); int N = scaler->kernel->size; if (N == 2) { GLSL(vec2 c1 = texture(lut, vec2(0.5, fcoord_lut)).rg;) GLSL(float weights[2] = float[](c1.r, c1.g);) } else if (N == 6) { GLSL(vec4 c1 = texture(lut, vec2(0.25, fcoord_lut));) GLSL(vec4 c2 = texture(lut, vec2(0.75, fcoord_lut));) GLSL(float weights[6] = float[](c1.r, c1.g, c1.b, c2.r, c2.g, c2.b);) } else { GLSLF("float weights[%d];\n", N); for (int n = 0; n < N / 4; n++) { GLSLF("c = texture(lut, vec2(1.0 / %d.0 + %d.0 / %d.0, fcoord_lut));\n", N / 2, n, N / 4); GLSLF("weights[%d] = c.r;\n", n * 4 + 0); GLSLF("weights[%d] = c.g;\n", n * 4 + 1); GLSLF("weights[%d] = c.b;\n", n * 4 + 2); GLSLF("weights[%d] = c.a;\n", n * 4 + 3); } } } // Handle a single pass (either vertical or horizontal). The direction is given // by the vector (d_x, d_y). If the vector is 0, then planar interpolation is // used instead (samples from texture0 through textureN) void pass_sample_separated_gen(struct gl_shader_cache *sc, struct scaler *scaler, int d_x, int d_y) { int N = scaler->kernel->size; bool use_ar = scaler->conf.antiring > 0; bool planar = d_x == 0 && d_y == 0; GLSL(color = vec4(0.0);) GLSLF("{\n"); if (!planar) { GLSLF("vec2 dir = vec2(%d.0, %d.0);\n", d_x, d_y); GLSL(pt *= dir;) GLSL(float fcoord = dot(fract(pos * size - vec2(0.5)), dir);) GLSLF("vec2 base = pos - fcoord * pt - pt * vec2(%d.0);\n", N / 2 - 1); } GLSL(vec4 c;) if (use_ar) { GLSL(vec4 hi = vec4(0.0);) GLSL(vec4 lo = vec4(1.0);) } pass_sample_separated_get_weights(sc, scaler); GLSLF("// scaler samples\n"); for (int n = 0; n < N; n++) { if (planar) { GLSLF("c = texture(texture%d, texcoord%d);\n", n, n); } else { GLSLF("c = texture(tex, base + pt * vec2(%d.0));\n", n); } GLSLF("color += vec4(weights[%d]) * c;\n", n); if (use_ar && (n == N/2-1 || n == N/2)) { GLSL(lo = min(lo, c);) GLSL(hi = max(hi, c);) } } if (use_ar) GLSLF("color = mix(color, clamp(color, lo, hi), %f);\n", scaler->conf.antiring); GLSLF("}\n"); } void pass_sample_polar(struct gl_shader_cache *sc, struct scaler *scaler) { double radius = scaler->kernel->f.radius; int bound = (int)ceil(radius); bool use_ar = scaler->conf.antiring > 0; GLSL(color = vec4(0.0);) GLSLF("{\n"); GLSL(vec2 fcoord = fract(pos * size - vec2(0.5));) GLSL(vec2 base = pos - fcoord * pt;) GLSL(vec4 c;) GLSLF("float w, d, wsum = 0.0;\n"); if (use_ar) { GLSL(vec4 lo = vec4(1.0);) GLSL(vec4 hi = vec4(0.0);) } gl_sc_uniform_tex(sc, "lut", scaler->gl_target, scaler->gl_lut); GLSLF("// scaler samples\n"); for (int y = 1-bound; y <= bound; y++) { for (int x = 1-bound; x <= bound; x++) { // Since we can't know the subpixel position in advance, assume a // worst case scenario int yy = y > 0 ? y-1 : y; int xx = x > 0 ? x-1 : x; double dmax = sqrt(xx*xx + yy*yy); // Skip samples definitely outside the radius if (dmax >= radius) continue; GLSLF("d = length(vec2(%d.0, %d.0) - fcoord)/%f;\n", x, y, radius); // Check for samples that might be skippable if (dmax >= radius - M_SQRT2) GLSLF("if (d < 1.0) {\n"); if (scaler->gl_target == GL_TEXTURE_1D) { GLSLF("w = texture1D(lut, LUT_POS(d, %d.0)).r;\n", scaler->lut_size); } else { GLSLF("w = texture(lut, vec2(0.5, LUT_POS(d, %d.0))).r;\n", scaler->lut_size); } GLSL(wsum += w;) GLSLF("c = texture(tex, base + pt * vec2(%d.0, %d.0));\n", x, y); GLSL(color += vec4(w) * c;) if (use_ar && x >= 0 && y >= 0 && x <= 1 && y <= 1) { GLSL(lo = min(lo, c);) GLSL(hi = max(hi, c);) } if (dmax >= radius - M_SQRT2) GLSLF("}\n"); } } GLSL(color = color / vec4(wsum);) if (use_ar) GLSLF("color = mix(color, clamp(color, lo, hi), %f);\n", scaler->conf.antiring); GLSLF("}\n"); } static void bicubic_calcweights(struct gl_shader_cache *sc, const char *t, const char *s) { // Explanation of how bicubic scaling with only 4 texel fetches is done: // http://www.mate.tue.nl/mate/pdfs/10318.pdf // 'Efficient GPU-Based Texture Interpolation using Uniform B-Splines' // Explanation why this algorithm normally always blurs, even with unit // scaling: // http://bigwww.epfl.ch/preprints/ruijters1001p.pdf // 'GPU Prefilter for Accurate Cubic B-spline Interpolation' GLSLF("vec4 %s = vec4(-0.5, 0.1666, 0.3333, -0.3333) * %s" " + vec4(1, 0, -0.5, 0.5);\n", t, s); GLSLF("%s = %s * %s + vec4(0, 0, -0.5, 0.5);\n", t, t, s); GLSLF("%s = %s * %s + vec4(-0.6666, 0, 0.8333, 0.1666);\n", t, t, s); GLSLF("%s.xy *= vec2(1, 1) / vec2(%s.z, %s.w);\n", t, t, t); GLSLF("%s.xy += vec2(1.0 + %s, 1.0 - %s);\n", t, s, s); } void pass_sample_bicubic_fast(struct gl_shader_cache *sc) { GLSLF("{\n"); GLSL(vec2 fcoord = fract(pos * size + vec2(0.5, 0.5));) bicubic_calcweights(sc, "parmx", "fcoord.x"); bicubic_calcweights(sc, "parmy", "fcoord.y"); GLSL(vec4 cdelta;) GLSL(cdelta.xz = parmx.rg * vec2(-pt.x, pt.x);) GLSL(cdelta.yw = parmy.rg * vec2(-pt.y, pt.y);) // first y-interpolation GLSL(vec4 ar = texture(tex, pos + cdelta.xy);) GLSL(vec4 ag = texture(tex, pos + cdelta.xw);) GLSL(vec4 ab = mix(ag, ar, parmy.b);) // second y-interpolation GLSL(vec4 br = texture(tex, pos + cdelta.zy);) GLSL(vec4 bg = texture(tex, pos + cdelta.zw);) GLSL(vec4 aa = mix(bg, br, parmy.b);) // x-interpolation GLSL(color = mix(aa, ab, parmx.b);) GLSLF("}\n"); } void pass_sample_oversample(struct gl_shader_cache *sc, struct scaler *scaler, int w, int h) { GLSLF("{\n"); GLSL(vec2 pos = pos + vec2(0.5) * pt;) // round to nearest GLSL(vec2 fcoord = fract(pos * size - vec2(0.5));) // Determine the mixing coefficient vector gl_sc_uniform_vec2(sc, "output_size", (float[2]){w, h}); GLSL(vec2 coeff = fcoord * output_size/size;) float threshold = scaler->conf.kernel.params[0]; threshold = isnan(threshold) ? 0.0 : threshold; GLSLF("coeff = (coeff - %f) / %f;\n", threshold, 1.0 - 2 * threshold); GLSL(coeff = clamp(coeff, 0.0, 1.0);) // Compute the right blend of colors GLSL(color = texture(tex, pos + pt * (coeff - fcoord));) GLSLF("}\n"); } // Common constants for SMPTE ST.2084 (HDR) static const float HDR_M1 = 2610./4096 * 1./4, HDR_M2 = 2523./4096 * 128, HDR_C1 = 3424./4096, HDR_C2 = 2413./4096 * 32, HDR_C3 = 2392./4096 * 32; // Common constants for ARIB STD-B67 (Hybrid Log-gamma) static const float B67_A = 0.17883277, B67_B = 0.28466892, B67_C = 0.55991073; // Common constants for Panasonic V-Log static const float VLOG_B = 0.00873, VLOG_C = 0.241514, VLOG_D = 0.598206, VLOG_R = 46.085527; // nominal peak // Linearize (expand), given a TRC as input. This corresponds to the EOTF // in ITU-R terminology. void pass_linearize(struct gl_shader_cache *sc, enum mp_csp_trc trc) { if (trc == MP_CSP_TRC_LINEAR) return; // Note that this clamp may technically violate the definition of // ITU-R BT.2100, which allows for sub-blacks and super-whites to be // displayed on the display where such would be possible. That said, the // problem is that not all gamma curves are well-defined on the values // outside this range, so we ignore it and just clip anyway for sanity. GLSL(color.rgb = clamp(color.rgb, 0.0, 1.0);) switch (trc) { case MP_CSP_TRC_SRGB: GLSL(color.rgb = mix(color.rgb / vec3(12.92), pow((color.rgb + vec3(0.055))/vec3(1.055), vec3(2.4)), lessThan(vec3(0.04045), color.rgb));) break; case MP_CSP_TRC_BT_1886: // We don't have an actual black point, so we assume a perfect display GLSL(color.rgb = pow(color.rgb, vec3(2.4));) break; case MP_CSP_TRC_GAMMA18: GLSL(color.rgb = pow(color.rgb, vec3(1.8));) break; case MP_CSP_TRC_GAMMA22: GLSL(color.rgb = pow(color.rgb, vec3(2.2));) break; case MP_CSP_TRC_GAMMA28: GLSL(color.rgb = pow(color.rgb, vec3(2.8));) break; case MP_CSP_TRC_PRO_PHOTO: GLSL(color.rgb = mix(color.rgb / vec3(16.0), pow(color.rgb, vec3(1.8)), lessThan(vec3(0.03125), color.rgb));) break; case MP_CSP_TRC_SMPTE_ST2084: GLSLF("color.rgb = pow(color.rgb, vec3(1.0/%f));\n", HDR_M2); GLSLF("color.rgb = max(color.rgb - vec3(%f), vec3(0.0)) \n" " / (vec3(%f) - vec3(%f) * color.rgb);\n", HDR_C1, HDR_C2, HDR_C3); GLSLF("color.rgb = pow(color.rgb, vec3(1.0/%f));\n", HDR_M1); break; case MP_CSP_TRC_ARIB_STD_B67: GLSLF("color.rgb = mix(vec3(4.0) * color.rgb * color.rgb,\n" " exp((color.rgb - vec3(%f)) / vec3(%f)) + vec3(%f),\n" " lessThan(vec3(0.5), color.rgb));\n", B67_C, B67_A, B67_B); // Since the ARIB function's signal value of 1.0 corresponds to // a peak of 12.0, we need to renormalize to prevent GL textures // from clipping. (In general, mpv's internal conversions always // assume 1.0 is the maximum brightness, not the reference peak) GLSL(color.rgb /= vec3(12.0);) break; case MP_CSP_TRC_V_LOG: GLSLF("color.rgb = mix((color.rgb - vec3(0.125)) / vec3(5.6), \n" " pow(vec3(10.0), (color.rgb - vec3(%f)) / vec3(%f)) \n" " - vec3(%f), \n" " lessThanEqual(vec3(0.181), color.rgb)); \n", VLOG_D, VLOG_C, VLOG_B); // Same deal as with the B67 function, renormalize to texture range GLSLF("color.rgb /= vec3(%f);\n", VLOG_R); GLSL(color.rgb = clamp(color.rgb, 0.0, 1.0);) break; default: abort(); } } // Delinearize (compress), given a TRC as output. This corresponds to the // inverse EOTF (not the OETF) in ITU-R terminology. void pass_delinearize(struct gl_shader_cache *sc, enum mp_csp_trc trc) { if (trc == MP_CSP_TRC_LINEAR) return; GLSL(color.rgb = clamp(color.rgb, 0.0, 1.0);) switch (trc) { case MP_CSP_TRC_SRGB: GLSL(color.rgb = mix(color.rgb * vec3(12.92), vec3(1.055) * pow(color.rgb, vec3(1.0/2.4)) - vec3(0.055), lessThanEqual(vec3(0.0031308), color.rgb));) break; case MP_CSP_TRC_BT_1886: GLSL(color.rgb = pow(color.rgb, vec3(1.0/2.4));) break; case MP_CSP_TRC_GAMMA18: GLSL(color.rgb = pow(color.rgb, vec3(1.0/1.8));) break; case MP_CSP_TRC_GAMMA22: GLSL(color.rgb = pow(color.rgb, vec3(1.0/2.2));) break; case MP_CSP_TRC_GAMMA28: GLSL(color.rgb = pow(color.rgb, vec3(1.0/2.8));) break; case MP_CSP_TRC_PRO_PHOTO: GLSL(color.rgb = mix(color.rgb * vec3(16.0), pow(color.rgb, vec3(1.0/1.8)), lessThanEqual(vec3(0.001953), color.rgb));) break; case MP_CSP_TRC_SMPTE_ST2084: GLSLF("color.rgb = pow(color.rgb, vec3(%f));\n", HDR_M1); GLSLF("color.rgb = (vec3(%f) + vec3(%f) * color.rgb) \n" " / (vec3(1.0) + vec3(%f) * color.rgb);\n", HDR_C1, HDR_C2, HDR_C3); GLSLF("color.rgb = pow(color.rgb, vec3(%f));\n", HDR_M2); break; case MP_CSP_TRC_ARIB_STD_B67: GLSL(color.rgb *= vec3(12.0);) GLSLF("color.rgb = mix(vec3(0.5) * sqrt(color.rgb),\n" " vec3(%f) * log(color.rgb - vec3(%f)) + vec3(%f),\n" " lessThan(vec3(1.0), color.rgb));\n", B67_A, B67_B, B67_C); break; case MP_CSP_TRC_V_LOG: GLSLF("color.rgb *= vec3(%f);\n", VLOG_R); GLSLF("color.rgb = mix(vec3(5.6) * color.rgb + vec3(0.125), \n" " vec3(%f) * log(color.rgb + vec3(%f)) \n" " + vec3(%f), \n" " lessThanEqual(vec3(0.01), color.rgb)); \n", VLOG_C / M_LN10, VLOG_B, VLOG_D); break; default: abort(); } } // Tone map from a known peak brightness to the range [0,1] static void pass_tone_map(struct gl_shader_cache *sc, float ref_peak, enum tone_mapping algo, float param) { GLSLF("// HDR tone mapping\n"); switch (algo) { case TONE_MAPPING_CLIP: GLSL(color.rgb = clamp(color.rgb, 0.0, 1.0);) break; case TONE_MAPPING_REINHARD: { float contrast = isnan(param) ? 0.5 : param, offset = (1.0 - contrast) / contrast; GLSLF("color.rgb = color.rgb / (color.rgb + vec3(%f));\n", offset); GLSLF("color.rgb *= vec3(%f);\n", (ref_peak + offset) / ref_peak); break; } case TONE_MAPPING_HABLE: { float A = 0.15, B = 0.50, C = 0.10, D = 0.20, E = 0.02, F = 0.30; GLSLHF("vec3 hable(vec3 x) {\n"); GLSLHF("return ((x * (%f*x + %f)+%f)/(x * (%f*x + %f) + %f)) - %f;\n", A, C*B, D*E, A, B, D*F, E/F); GLSLHF("}\n"); GLSLF("color.rgb = hable(color.rgb) / hable(vec3(%f));\n", ref_peak); break; } case TONE_MAPPING_GAMMA: { float gamma = isnan(param) ? 1.8 : param; GLSLF("color.rgb = pow(color.rgb / vec3(%f), vec3(%f));\n", ref_peak, 1.0/gamma); break; } case TONE_MAPPING_LINEAR: { float coeff = isnan(param) ? 1.0 : param; GLSLF("color.rgb = vec3(%f) * color.rgb;\n", coeff / ref_peak); break; } default: abort(); } } // Map colors from one source space to another. These source spaces // must be known (i.e. not MP_CSP_*_AUTO), as this function won't perform // any auto-guessing. void pass_color_map(struct gl_shader_cache *sc, struct mp_colorspace src, struct mp_colorspace dst, enum tone_mapping algo, float tone_mapping_param) { GLSLF("// color mapping\n"); // All operations from here on require linear light as a starting point, // so we linearize even if src.gamma == dst.gamma when one of the other // operations needs it bool need_gamma = src.gamma != dst.gamma || src.primaries != dst.primaries || src.nom_peak != dst.nom_peak || src.sig_peak > dst.nom_peak; if (need_gamma) pass_linearize(sc, src.gamma); // NOTE: When src.gamma = MP_CSP_TRC_ARIB_STD_B67, we would technically // need to apply the reference OOTF as part of the EOTF (which is what we // implement with pass_linearize), since HLG considers OOTF to be part of // the display's EOTF (as opposed to the camera's OETF). But since this is // stupid, complicated, arbitrary, and more importantly depends on the // target display's signal peak (which is != the nom_peak in the case of // HDR displays, and mpv already has enough target-specific display // options), we just ignore its implementation entirely. (Plus, it doesn't // even really make sense with tone mapping to begin with.) But just in // case somebody ends up complaining about HLG looking different from a // reference HLG display, this comment might be why. // Stretch the signal value to renormalize to the dst nominal peak if (src.nom_peak != dst.nom_peak) GLSLF("color.rgb *= vec3(%f);\n", src.nom_peak / dst.nom_peak); // Tone map to prevent clipping when the source signal peak exceeds the // encodable range. if (src.sig_peak > dst.nom_peak) pass_tone_map(sc, src.sig_peak / dst.nom_peak, algo, tone_mapping_param); // Adapt to the right colorspace if necessary if (src.primaries != dst.primaries) { struct mp_csp_primaries csp_src = mp_get_csp_primaries(src.primaries), csp_dst = mp_get_csp_primaries(dst.primaries); float m[3][3] = {{0}}; mp_get_cms_matrix(csp_src, csp_dst, MP_INTENT_RELATIVE_COLORIMETRIC, m); gl_sc_uniform_mat3(sc, "cms_matrix", true, &m[0][0]); GLSL(color.rgb = cms_matrix * color.rgb;) } if (need_gamma) pass_delinearize(sc, dst.gamma); } // Wide usage friendly PRNG, shamelessly stolen from a GLSL tricks forum post. // Obtain random numbers by calling rand(h), followed by h = permute(h) to // update the state. Assumes the texture was hooked. static void prng_init(struct gl_shader_cache *sc, AVLFG *lfg) { GLSLH(float mod289(float x) { return x - floor(x / 289.0) * 289.0; }) GLSLH(float permute(float x) { return mod289((34.0*x + 1.0) * x); }) GLSLH(float rand(float x) { return fract(x / 41.0); }) // Initialize the PRNG by hashing the position + a random uniform GLSL(vec3 _m = vec3(HOOKED_pos, random) + vec3(1.0);) GLSL(float h = permute(permute(permute(_m.x)+_m.y)+_m.z);) gl_sc_uniform_f(sc, "random", (double)av_lfg_get(lfg) / UINT32_MAX); } struct deband_opts { int enabled; int iterations; float threshold; float range; float grain; }; const struct deband_opts deband_opts_def = { .iterations = 1, .threshold = 64.0, .range = 16.0, .grain = 48.0, }; #define OPT_BASE_STRUCT struct deband_opts const struct m_sub_options deband_conf = { .opts = (const m_option_t[]) { OPT_INTRANGE("iterations", iterations, 0, 1, 16), OPT_FLOATRANGE("threshold", threshold, 0, 0.0, 4096.0), OPT_FLOATRANGE("range", range, 0, 1.0, 64.0), OPT_FLOATRANGE("grain", grain, 0, 0.0, 4096.0), {0} }, .size = sizeof(struct deband_opts), .defaults = &deband_opts_def, }; // Stochastically sample a debanded result from a hooked texture. void pass_sample_deband(struct gl_shader_cache *sc, struct deband_opts *opts, AVLFG *lfg) { // Initialize the PRNG GLSLF("{\n"); prng_init(sc, lfg); // Helper: Compute a stochastic approximation of the avg color around a // pixel GLSLHF("vec4 average(float range, inout float h) {\n"); // Compute a random rangle and distance GLSLH(float dist = rand(h) * range; h = permute(h);) GLSLH(float dir = rand(h) * 6.2831853; h = permute(h);) GLSLH(vec2 o = dist * vec2(cos(dir), sin(dir));) // Sample at quarter-turn intervals around the source pixel GLSLH(vec4 ref[4];) GLSLH(ref[0] = HOOKED_texOff(vec2( o.x, o.y));) GLSLH(ref[1] = HOOKED_texOff(vec2(-o.y, o.x));) GLSLH(ref[2] = HOOKED_texOff(vec2(-o.x, -o.y));) GLSLH(ref[3] = HOOKED_texOff(vec2( o.y, -o.x));) // Return the (normalized) average GLSLH(return (ref[0] + ref[1] + ref[2] + ref[3])/4.0;) GLSLHF("}\n"); // Sample the source pixel GLSL(color = HOOKED_tex(HOOKED_pos);) GLSLF("vec4 avg, diff;\n"); for (int i = 1; i <= opts->iterations; i++) { // Sample the average pixel and use it instead of the original if // the difference is below the given threshold GLSLF("avg = average(%f, h);\n", i * opts->range); GLSL(diff = abs(color - avg);) GLSLF("color = mix(avg, color, greaterThan(diff, vec4(%f)));\n", opts->threshold / (i * 16384.0)); } // Add some random noise to smooth out residual differences GLSL(vec3 noise;) GLSL(noise.x = rand(h); h = permute(h);) GLSL(noise.y = rand(h); h = permute(h);) GLSL(noise.z = rand(h); h = permute(h);) GLSLF("color.xyz += %f * (noise - vec3(0.5));\n", opts->grain/8192.0); GLSLF("}\n"); } // Assumes the texture was hooked void pass_sample_unsharp(struct gl_shader_cache *sc, float param) { GLSLF("// unsharp\n"); GLSLF("{\n"); GLSL(float st1 = 1.2;) GLSL(vec4 p = HOOKED_tex(HOOKED_pos);) GLSL(vec4 sum1 = HOOKED_texOff(st1 * vec2(+1, +1)) + HOOKED_texOff(st1 * vec2(+1, -1)) + HOOKED_texOff(st1 * vec2(-1, +1)) + HOOKED_texOff(st1 * vec2(-1, -1));) GLSL(float st2 = 1.5;) GLSL(vec4 sum2 = HOOKED_texOff(st2 * vec2(+1, 0)) + HOOKED_texOff(st2 * vec2( 0, +1)) + HOOKED_texOff(st2 * vec2(-1, 0)) + HOOKED_texOff(st2 * vec2( 0, -1));) GLSL(vec4 t = p * 0.859375 + sum2 * -0.1171875 + sum1 * -0.09765625;) GLSLF("color = p + t * %f;\n", param); GLSLF("}\n"); }