bool GWriteBitmapToFile(const GBitmap& bitmap, const char path[]) { FILE* f = ::fopen(path, "wb"); if (!f) { return false; } GAutoFClose afc(f); png_structp png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL); if (!png_ptr) { return false; } png_infop info_ptr = png_create_info_struct(png_ptr); if (!info_ptr) { png_destroy_write_struct(&png_ptr, NULL); return false; } if (setjmp(png_jmpbuf(png_ptr))) { png_destroy_write_struct(&png_ptr, &info_ptr); return false; } png_init_io(png_ptr, f); if (setjmp(png_jmpbuf(png_ptr))) { return false; } const int bitDepth = 8; png_set_IHDR(png_ptr, info_ptr, bitmap.fWidth, bitmap.fHeight, bitDepth, PNG_COLOR_TYPE_RGB_ALPHA, PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE); png_write_info(png_ptr, info_ptr); char* scanline = (char*)malloc(bitmap.fWidth * 4); GAutoFree gaf(scanline); const GPixel* srcRow = bitmap.fPixels; for (int y = 0; y < bitmap.fHeight; y++) { convertToPNG(srcRow, bitmap.fWidth, scanline); png_bytep row_ptr = (png_bytep)scanline; png_write_rows(png_ptr, &row_ptr, 1); srcRow = (const GPixel*)((const char*)srcRow + bitmap.fRowBytes); } png_write_end(png_ptr, NULL); png_destroy_write_struct(&png_ptr, &info_ptr); return true; }
// rhyper(NR, NB, n) -- NR 'red', NB 'blue', n drawn, how many are 'red' double rhyper(double nn1in, double nn2in, double kkin) { /* extern double afc(int); */ int nn1, nn2, kk; int ix; // return value (coerced to double at the very end) Rboolean setup1, setup2; /* These should become 'thread_local globals' : */ static int ks = -1, n1s = -1, n2s = -1; static int m, minjx, maxjx; static int k, n1, n2; // <- not allowing larger integer par static double tn; // II : static double w; // III: static double a, d, s, xl, xr, kl, kr, lamdl, lamdr, p1, p2, p3; /* check parameter validity */ if(!R_FINITE(nn1in) || !R_FINITE(nn2in) || !R_FINITE(kkin)) ML_ERR_return_NAN; nn1in = R_forceint(nn1in); nn2in = R_forceint(nn2in); kkin = R_forceint(kkin); if (nn1in < 0 || nn2in < 0 || kkin < 0 || kkin > nn1in + nn2in) ML_ERR_return_NAN; if (nn1in >= INT_MAX || nn2in >= INT_MAX || kkin >= INT_MAX) { /* large n -- evade integer overflow (and inappropriate algorithms) -------- */ // FIXME: Much faster to give rbinom() approx when appropriate; -> see Kuensch(1989) // Johnson, Kotz,.. p.258 (top) mention the *four* different binomial approximations if(kkin == 1.) { // Bernoulli return rbinom(kkin, nn1in / (nn1in + nn2in)); } // Slow, but safe: return F^{-1}(U) where F(.) = phyper(.) and U ~ U[0,1] return qhyper(unif_rand(), nn1in, nn2in, kkin, FALSE, FALSE); } nn1 = (int)nn1in; nn2 = (int)nn2in; kk = (int)kkin; /* if new parameter values, initialize */ if (nn1 != n1s || nn2 != n2s) { setup1 = TRUE; setup2 = TRUE; } else if (kk != ks) { setup1 = FALSE; setup2 = TRUE; } else { setup1 = FALSE; setup2 = FALSE; } if (setup1) { n1s = nn1; n2s = nn2; tn = nn1 + nn2; if (nn1 <= nn2) { n1 = nn1; n2 = nn2; } else { n1 = nn2; n2 = nn1; } } if (setup2) { ks = kk; if (kk + kk >= tn) { k = (int)(tn - kk); } else { k = kk; } } if (setup1 || setup2) { m = (int) ((k + 1.) * (n1 + 1.) / (tn + 2.)); minjx = imax2(0, k - n2); maxjx = imin2(n1, k); #ifdef DEBUG_rhyper REprintf("rhyper(nn1=%d, nn2=%d, kk=%d), setup: floor(mean)= m=%d, jx in (%d..%d)\n", nn1, nn2, kk, m, minjx, maxjx); #endif } /* generate random variate --- Three basic cases */ if (minjx == maxjx) { /* I: degenerate distribution ---------------- */ #ifdef DEBUG_rhyper REprintf("rhyper(), branch I (degenerate)\n"); #endif ix = maxjx; goto L_finis; // return appropriate variate } else if (m - minjx < 10) { // II: (Scaled) algorithm HIN (inverse transformation) ---- const static double scale = 1e25; // scaling factor against (early) underflow const static double con = 57.5646273248511421; // 25*log(10) = log(scale) { <==> exp(con) == scale } if (setup1 || setup2) { double lw; // log(w); w = exp(lw) * scale = exp(lw + log(scale)) = exp(lw + con) if (k < n2) { lw = afc(n2) + afc(n1 + n2 - k) - afc(n2 - k) - afc(n1 + n2); } else { lw = afc(n1) + afc( k ) - afc(k - n2) - afc(n1 + n2); } w = exp(lw + con); } double p, u; #ifdef DEBUG_rhyper REprintf("rhyper(), branch II; w = %g > 0\n", w); #endif L10: p = w; ix = minjx; u = unif_rand() * scale; #ifdef DEBUG_rhyper REprintf(" _new_ u = %g\n", u); #endif while (u > p) { u -= p; p *= ((double) n1 - ix) * (k - ix); ix++; p = p / ix / (n2 - k + ix); #ifdef DEBUG_rhyper REprintf(" ix=%3d, u=%11g, p=%20.14g (u-p=%g)\n", ix, u, p, u-p); #endif if (ix > maxjx) goto L10; // FIXME if(p == 0.) we also "have lost" => goto L10 } } else { /* III : H2PE Algorithm --------------------------------------- */ double u,v; if (setup1 || setup2) { s = sqrt((tn - k) * k * n1 * n2 / (tn - 1) / tn / tn); /* remark: d is defined in reference without int. */ /* the truncation centers the cell boundaries at 0.5 */ d = (int) (1.5 * s) + .5; xl = m - d + .5; xr = m + d + .5; a = afc(m) + afc(n1 - m) + afc(k - m) + afc(n2 - k + m); kl = exp(a - afc((int) (xl)) - afc((int) (n1 - xl)) - afc((int) (k - xl)) - afc((int) (n2 - k + xl))); kr = exp(a - afc((int) (xr - 1)) - afc((int) (n1 - xr + 1)) - afc((int) (k - xr + 1)) - afc((int) (n2 - k + xr - 1))); lamdl = -log(xl * (n2 - k + xl) / (n1 - xl + 1) / (k - xl + 1)); lamdr = -log((n1 - xr + 1) * (k - xr + 1) / xr / (n2 - k + xr)); p1 = d + d; p2 = p1 + kl / lamdl; p3 = p2 + kr / lamdr; } #ifdef DEBUG_rhyper REprintf("rhyper(), branch III {accept/reject}: (xl,xr)= (%g,%g); (lamdl,lamdr)= (%g,%g)\n", xl, xr, lamdl,lamdr); REprintf("-------- p123= c(%g,%g,%g)\n", p1,p2, p3); #endif int n_uv = 0; L30: u = unif_rand() * p3; v = unif_rand(); n_uv++; if(n_uv >= 10000) { REprintf("rhyper() branch III: giving up after %d rejections", n_uv); ML_ERR_return_NAN; } #ifdef DEBUG_rhyper REprintf(" ... L30: new (u=%g, v ~ U[0,1])[%d]\n", u, n_uv); #endif if (u < p1) { /* rectangular region */ ix = (int) (xl + u); } else if (u <= p2) { /* left tail */ ix = (int) (xl + log(v) / lamdl); if (ix < minjx) goto L30; v = v * (u - p1) * lamdl; } else { /* right tail */ ix = (int) (xr - log(v) / lamdr); if (ix > maxjx) goto L30; v = v * (u - p2) * lamdr; } /* acceptance/rejection test */ Rboolean reject = TRUE; if (m < 100 || ix <= 50) { /* explicit evaluation */ /* The original algorithm (and TOMS 668) have f = f * i * (n2 - k + i) / (n1 - i) / (k - i); in the (m > ix) case, but the definition of the recurrence relation on p134 shows that the +1 is needed. */ int i; double f = 1.0; if (m < ix) { for (i = m + 1; i <= ix; i++) f = f * (n1 - i + 1) * (k - i + 1) / (n2 - k + i) / i; } else if (m > ix) { for (i = ix + 1; i <= m; i++) f = f * i * (n2 - k + i) / (n1 - i + 1) / (k - i + 1); } if (v <= f) { reject = FALSE; } } else { const static double deltal = 0.0078; const static double deltau = 0.0034; double e, g, r, t, y; double de, dg, dr, ds, dt, gl, gu, nk, nm, ub; double xk, xm, xn, y1, ym, yn, yk, alv; #ifdef DEBUG_rhyper REprintf(" ... accept/reject 'large' case v=%g\n", v); #endif /* squeeze using upper and lower bounds */ y = ix; y1 = y + 1.0; ym = y - m; yn = n1 - y + 1.0; yk = k - y + 1.0; nk = n2 - k + y1; r = -ym / y1; s = ym / yn; t = ym / yk; e = -ym / nk; g = yn * yk / (y1 * nk) - 1.0; dg = 1.0; if (g < 0.0) dg = 1.0 + g; gu = g * (1.0 + g * (-0.5 + g / 3.0)); gl = gu - .25 * (g * g * g * g) / dg; xm = m + 0.5; xn = n1 - m + 0.5; xk = k - m + 0.5; nm = n2 - k + xm; ub = y * gu - m * gl + deltau + xm * r * (1. + r * (-0.5 + r / 3.0)) + xn * s * (1. + s * (-0.5 + s / 3.0)) + xk * t * (1. + t * (-0.5 + t / 3.0)) + nm * e * (1. + e * (-0.5 + e / 3.0)); /* test against upper bound */ alv = log(v); if (alv > ub) { reject = TRUE; } else { /* test against lower bound */ dr = xm * (r * r * r * r); if (r < 0.0) dr /= (1.0 + r); ds = xn * (s * s * s * s); if (s < 0.0) ds /= (1.0 + s); dt = xk * (t * t * t * t); if (t < 0.0) dt /= (1.0 + t); de = nm * (e * e * e * e); if (e < 0.0) de /= (1.0 + e); if (alv < ub - 0.25 * (dr + ds + dt + de) + (y + m) * (gl - gu) - deltal) { reject = FALSE; } else { /* * Stirling's formula to machine accuracy */ if (alv <= (a - afc(ix) - afc(n1 - ix) - afc(k - ix) - afc(n2 - k + ix))) { reject = FALSE; } else { reject = TRUE; } } } } // else if (reject) goto L30; } L_finis: /* return appropriate variate */ if (kk + kk >= tn) { if (nn1 > nn2) { ix = kk - nn2 + ix; } else { ix = nn1 - ix; } } else { if (nn1 > nn2) ix = kk - ix; } return ix; }
double rhyper(double nn1in, double nn2in, double kkin) { const static double con = 57.56462733; const static double deltal = 0.0078; const static double deltau = 0.0034; const static double scale = 1e25; /* extern double afc(int); */ int nn1, nn2, kk; int i, ix; Rboolean reject, setup1, setup2; double e, f, g, p, r, t, u, v, y; double de, dg, dr, ds, dt, gl, gu, nk, nm, ub; double xk, xm, xn, y1, ym, yn, yk, alv; /* These should become `thread_local globals' : */ static int ks = -1; static int n1s = -1, n2s = -1; static int k, m; static int minjx, maxjx, n1, n2; static double a, d, s, w; static double tn, xl, xr, kl, kr, lamdl, lamdr, p1, p2, p3; /* check parameter validity */ if(!R_FINITE(nn1in) || !R_FINITE(nn2in) || !R_FINITE(kkin)) ML_ERR_return_NAN; nn1 = floor(nn1in+0.5); nn2 = floor(nn2in+0.5); kk = floor(kkin +0.5); if (nn1 < 0 || nn2 < 0 || kk < 0 || kk > nn1 + nn2) ML_ERR_return_NAN; /* if new parameter values, initialize */ reject = TRUE; if (nn1 != n1s || nn2 != n2s) { setup1 = TRUE; setup2 = TRUE; } else if (kk != ks) { setup1 = FALSE; setup2 = TRUE; } else { setup1 = FALSE; setup2 = FALSE; } if (setup1) { n1s = nn1; n2s = nn2; tn = nn1 + nn2; if (nn1 <= nn2) { n1 = nn1; n2 = nn2; } else { n1 = nn2; n2 = nn1; } } if (setup2) { ks = kk; if (kk + kk >= tn) { k = tn - kk; } else { k = kk; } } if (setup1 || setup2) { m = (k + 1.0) * (n1 + 1.0) / (tn + 2.0); minjx = imax2(0, k - n2); maxjx = imin2(n1, k); } /* generate random variate --- Three basic cases */ if (minjx == maxjx) { /* I: degenerate distribution ---------------- */ ix = maxjx; /* return ix; No, need to unmangle <TSL>*/ /* return appropriate variate */ if (kk + kk >= tn) { if (nn1 > nn2) { ix = kk - nn2 + ix; } else { ix = nn1 - ix; } } else { if (nn1 > nn2) ix = kk - ix; } return ix; } else if (m - minjx < 10) { /* II: inverse transformation ---------- */ if (setup1 || setup2) { if (k < n2) { w = exp(con + afc(n2) + afc(n1 + n2 - k) - afc(n2 - k) - afc(n1 + n2)); } else { w = exp(con + afc(n1) + afc(k) - afc(k - n2) - afc(n1 + n2)); } } L10: p = w; ix = minjx; u = unif_rand() * scale; L20: if (u > p) { u -= p; p *= (n1 - ix) * (k - ix); ix++; p = p / ix / (n2 - k + ix); if (ix > maxjx) goto L10; goto L20; } } else { /* III : h2pe --------------------------------------------- */ if (setup1 || setup2) { s = sqrt((tn - k) * k * n1 * n2 / (tn - 1) / tn / tn); /* remark: d is defined in reference without int. */ /* the truncation centers the cell boundaries at 0.5 */ d = (int) (1.5 * s) + .5; xl = m - d + .5; xr = m + d + .5; a = afc(m) + afc(n1 - m) + afc(k - m) + afc(n2 - k + m); kl = exp(a - afc((int) (xl)) - afc((int) (n1 - xl)) - afc((int) (k - xl)) - afc((int) (n2 - k + xl))); kr = exp(a - afc((int) (xr - 1)) - afc((int) (n1 - xr + 1)) - afc((int) (k - xr + 1)) - afc((int) (n2 - k + xr - 1))); lamdl = -log(xl * (n2 - k + xl) / (n1 - xl + 1) / (k - xl + 1)); lamdr = -log((n1 - xr + 1) * (k - xr + 1) / xr / (n2 - k + xr)); p1 = d + d; p2 = p1 + kl / lamdl; p3 = p2 + kr / lamdr; } L30: u = unif_rand() * p3; v = unif_rand(); if (u < p1) { /* rectangular region */ ix = xl + u; } else if (u <= p2) { /* left tail */ ix = xl + log(v) / lamdl; if (ix < minjx) goto L30; v = v * (u - p1) * lamdl; } else { /* right tail */ ix = xr - log(v) / lamdr; if (ix > maxjx) goto L30; v = v * (u - p2) * lamdr; } /* acceptance/rejection test */ if (m < 100 || ix <= 50) { /* explicit evaluation */ /* The original algorithm (and TOMS 668) have f = f * i * (n2 - k + i) / (n1 - i) / (k - i); in the (m > ix) case, but the definition of the recurrence relation on p134 shows that the +1 is needed. */ f = 1.0; if (m < ix) { for (i = m + 1; i <= ix; i++) f = f * (n1 - i + 1) * (k - i + 1) / (n2 - k + i) / i; } else if (m > ix) { for (i = ix + 1; i <= m; i++) f = f * i * (n2 - k + i) / (n1 - i + 1) / (k - i + 1); } if (v <= f) { reject = FALSE; } } else { /* squeeze using upper and lower bounds */ y = ix; y1 = y + 1.0; ym = y - m; yn = n1 - y + 1.0; yk = k - y + 1.0; nk = n2 - k + y1; r = -ym / y1; s = ym / yn; t = ym / yk; e = -ym / nk; g = yn * yk / (y1 * nk) - 1.0; dg = 1.0; if (g < 0.0) dg = 1.0 + g; gu = g * (1.0 + g * (-0.5 + g / 3.0)); gl = gu - .25 * (g * g * g * g) / dg; xm = m + 0.5; xn = n1 - m + 0.5; xk = k - m + 0.5; nm = n2 - k + xm; ub = y * gu - m * gl + deltau + xm * r * (1. + r * (-0.5 + r / 3.0)) + xn * s * (1. + s * (-0.5 + s / 3.0)) + xk * t * (1. + t * (-0.5 + t / 3.0)) + nm * e * (1. + e * (-0.5 + e / 3.0)); /* test against upper bound */ alv = log(v); if (alv > ub) { reject = TRUE; } else { /* test against lower bound */ dr = xm * (r * r * r * r); if (r < 0.0) dr /= (1.0 + r); ds = xn * (s * s * s * s); if (s < 0.0) ds /= (1.0 + s); dt = xk * (t * t * t * t); if (t < 0.0) dt /= (1.0 + t); de = nm * (e * e * e * e); if (e < 0.0) de /= (1.0 + e); if (alv < ub - 0.25 * (dr + ds + dt + de) + (y + m) * (gl - gu) - deltal) { reject = FALSE; } else { /* * Stirling's formula to machine accuracy */ if (alv <= (a - afc(ix) - afc(n1 - ix) - afc(k - ix) - afc(n2 - k + ix))) { reject = FALSE; } else { reject = TRUE; } } } } if (reject) goto L30; } /* return appropriate variate */ if (kk + kk >= tn) { if (nn1 > nn2) { ix = kk - nn2 + ix; } else { ix = nn1 - ix; } } else { if (nn1 > nn2) ix = kk - ix; } return ix; }
bool GReadBitmapFromFile(const char path[], GBitmap* bitmap) { FILE* file = fopen(path, "rb"); if (NULL == file) { return always_false(); } GAutoFClose afc(file); uint8_t signature[SIGNATURE_BYTES]; if (SIGNATURE_BYTES != fread(signature, 1, SIGNATURE_BYTES, file)) { return always_false(); } if (png_sig_cmp(signature, 0, SIGNATURE_BYTES)) { return always_false(); } png_structp png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL); if (NULL == png_ptr) { return always_false(); } png_infop info_ptr = png_create_info_struct(png_ptr); if (NULL == info_ptr) { png_destroy_read_struct(&png_ptr, NULL, NULL); return always_false(); } GAutoPNGReader reader(png_ptr, info_ptr); if (setjmp(png_jmpbuf(png_ptr))) { return always_false(); } png_init_io(png_ptr, file); png_set_sig_bytes(png_ptr, SIGNATURE_BYTES); png_read_info(png_ptr, info_ptr); png_uint_32 width, height; int bitDepth, colorType; png_get_IHDR(png_ptr, info_ptr, &width, &height, &bitDepth, &colorType, NULL, NULL, NULL); if (8 != bitDepth) { return always_false(); // TODO: handle other formats } if (png_set_interlace_handling(png_ptr) > 1) { return always_false(); // TODO: support interleave } swizzle_row_proc row_proc = NULL; switch (colorType) { case PNG_COLOR_TYPE_RGB: row_proc = swizzle_rgb_row; break; case PNG_COLOR_TYPE_RGB_ALPHA: row_proc = swizzle_rgba_row; break; default: return always_false(); } png_read_update_info(png_ptr, info_ptr); GAutoFree rowStorage(malloc(png_get_rowbytes(png_ptr, info_ptr))); png_bytep srcRow = (png_bytep)rowStorage.get(); if (!srcRow) { return always_false(); } GAutoFree pixelStorage(malloc(height * width * 4)); GPixel* dstRow = (GPixel*)pixelStorage.get(); if (NULL == dstRow) { return always_false(); } for (int y = 0; y < height; y++) { uint8_t* tmp = srcRow; png_read_rows(png_ptr, &tmp, NULL, 1); row_proc(dstRow, srcRow, width); dstRow += width; } bitmap->fWidth = width; bitmap->fHeight = height; bitmap->fRowBytes = width * 4; bitmap->fPixels = (GPixel*)pixelStorage.detach(); return true; }