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add libquadmath implementation

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josch 2013-06-27 15:18:37 +02:00
parent 0e9cee9223
commit faf340ecab
3 changed files with 114 additions and 3 deletions
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4
Makefile Normal file
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@ -0,0 +1,4 @@
all:
gcc -Ofast -Wall -lquadmath mandel_quad.c -o mandel_quad
gcc -Ofast -Wall -lmpfr mandel_mpfr.c -o mandel_mpfr
gcc -Ofast -Wall -lm mandel.c -o mandel

9
mandel_mpfr.c
View file

@ -16,8 +16,10 @@ int main(int argc, char **argv) {
mpfr_init2(temp2, 300);
long double eps = 1e-17;
mpfr_t Q1LOG2, LOG2;
mpfr_init_set_str(Q1LOG2, "1.44269504088896340735992468100189213742664595415299", 10, MPFR_RNDN);
mpfr_init_set_str(LOG2, "0.69314718055994530941723212145817656807550013436026", 10, MPFR_RNDN);
mpfr_init2(Q1LOG2, 300);
mpfr_init2(LOG2, 300);
mpfr_set_str(Q1LOG2, "1.44269504088896340735992468100189213742664595415299", 10, MPFR_RNDN);
mpfr_set_str(LOG2, "0.69314718055994530941723212145817656807550013436026", 10, MPFR_RNDN);
unsigned int width = atoi(argv[1]);
unsigned int height = atoi(argv[2]);
char* image = malloc(width*height*3);
@ -43,7 +45,8 @@ int main(int argc, char **argv) {
mpfr_log(logLogBailout, logLogBailout, MPFR_RNDN);
mpfr_log(logLogBailout, logLogBailout, MPFR_RNDN);
mpfr_t magn;
mpfr_init_set_str(magn, argv[5], 10, MPFR_RNDN);
mpfr_init2(magn, 300);
mpfr_set_str(magn, argv[5], 10, MPFR_RNDN);
// maxiter = width * sqrt(magn);
mpfr_sqrt(temp1, magn, MPFR_RNDN);
unsigned long maxiter = width * mpfr_get_ui(temp1, MPFR_RNDN);

104
mandel_quad.c Normal file
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@ -0,0 +1,104 @@
#include "colors.h"
#include <quadmath.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
int main(int argc, char **argv) {
if (argc != 6) {
fprintf(stderr, "usage: %s width height centerx centery magnification", argv[0]);
return 1;
}
__float128 eps = 1e-17;
__float128 Q1LOG2, LOG2;
Q1LOG2 = strtoflt128("1.44269504088896340735992468100189213742664595415299", NULL);
LOG2 = strtoflt128("0.69314718055994530941723212145817656807550013436026", NULL);
unsigned int width = atoi(argv[1]);
unsigned int height = atoi(argv[2]);
char* image = malloc(width*height*3);
int x, y;
__float128 centerx, centery;
centerx = strtoflt128(argv[3], NULL);
centery = strtoflt128(argv[4], NULL);
__float128 bailout = 128;
__float128 logLogBailout = logq(logq(bailout));
int foundperiods = 0;
__float128 magn = strtoflt128(argv[5], NULL);
long maxiter = width * sqrtq(magn);
__float128 x0d = 4 / magn / width;
__float128 x2 = -2 / magn + centerx;
__float128 y1d = -4 / magn / width;
__float128 y2 = 2 / magn * height / width + centery;
int imgidx = 0;
for (y = 0; y < height; y++) {
for (x = 0; x < width; x++) {
fprintf(stderr, "\r%f %%", (float)imgidx/(width*height*3)*100);
__float128 px = x*x0d + x2;
__float128 py = y*y1d + y2;
// no Main bulb or Cardoid check to be faster
__float128 zx = px;
__float128 zy = py;
long i;
// Initial maximum period to detect.
int check = 3;
// Maximum period doubles every iterations:
int whenupdate = 10;
// Period history registers.
__float128 hx = 0;
__float128 hy = 0;
__float128 xx, yy;
bool inside = true;
for (i = 1; i <= maxiter; i++) {
xx = zx * zx;
yy = zy * zy;
if (xx + yy > bailout) {
inside = false;
break;
}
// iterate
zy = 2 * zx * zy + py;
zx = xx - yy + px;
// periodicity check
__float128 d = zx - hx;
if (d > 0.0 ? d < eps : d > -eps) {
d = zy - hy;
if (d > 0.0 ? d < eps : d > -eps) {
// Period found.
foundperiods++;
break;
}
}
if ((i & check) == 0) {
if (--whenupdate == 0) {
whenupdate = 10;
check <<= 1;
check++;
}
// period = 0;
hx = zx;
hy = zy;
}
}
if (inside) {
image[imgidx++] = 0;
image[imgidx++] = 0;
image[imgidx++] = 0;
} else {
__float128 r = sqrtq(zx*zx + zy*zy);
__float128 c = i - 1.28 + (logLogBailout - logq(logq(r))) * Q1LOG2;
int idx = fmodq((logq(c/64+1)/LOG2+0.45), 1)*GRADIENTLENGTH + 0.5;
image[imgidx++] = colors[idx][0];
image[imgidx++] = colors[idx][1];
image[imgidx++] = colors[idx][2];
}
}
}
// write out image
printf("P6 %d %d 255\n", width, height);
fwrite(image, 1, width*height*3, stdout);
//fprintf(stderr, "%d periods found\n", foundperiods);
return 0;
}