mirror of
https://github.com/golang/go
synced 2024-11-25 03:27:58 -07:00
eb056dbea7
Surprise! The C code is using floating point values for its counters. Its off the critical path, but the Go code and C code are supposed to be as similar as possible to make comparisons meaningful. It doesn't have a significant effect. R=golang-dev, r CC=golang-dev https://golang.org/cl/6260058
96 lines
2.6 KiB
Go
96 lines
2.6 KiB
Go
/*
|
|
Redistribution and use in source and binary forms, with or without
|
|
modification, are permitted provided that the following conditions are met:
|
|
|
|
* Redistributions of source code must retain the above copyright
|
|
notice, this list of conditions and the following disclaimer.
|
|
|
|
* Redistributions in binary form must reproduce the above copyright
|
|
notice, this list of conditions and the following disclaimer in the
|
|
documentation and/or other materials provided with the distribution.
|
|
|
|
* Neither the name of "The Computer Language Benchmarks Game" nor the
|
|
name of "The Computer Language Shootout Benchmarks" nor the names of
|
|
its contributors may be used to endorse or promote products derived
|
|
from this software without specific prior written permission.
|
|
|
|
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
|
|
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
|
|
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
|
|
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
|
|
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
|
|
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
|
|
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
|
|
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
|
POSSIBILITY OF SUCH DAMAGE.
|
|
*/
|
|
|
|
/* The Computer Language Benchmarks Game
|
|
* http://shootout.alioth.debian.org/
|
|
*
|
|
* contributed by The Go Authors.
|
|
* Based on mandelbrot.c contributed by Greg Buchholz
|
|
*/
|
|
|
|
package main
|
|
|
|
import (
|
|
"bufio"
|
|
"flag"
|
|
"fmt"
|
|
"os"
|
|
)
|
|
|
|
var n = flag.Int("n", 200, "size")
|
|
|
|
func main() {
|
|
flag.Parse()
|
|
out := bufio.NewWriter(os.Stdout)
|
|
defer out.Flush()
|
|
|
|
w := float64(*n)
|
|
h := float64(*n)
|
|
bit_num := 0
|
|
byte_acc := byte(0)
|
|
const Iter = 50
|
|
const Zero float64 = 0
|
|
const Limit = 2.0
|
|
|
|
fmt.Fprintf(out, "P4\n%d %d\n", *n, *n)
|
|
|
|
for y := 0.0; y < h; y++ {
|
|
for x := 0.0; x < w; x++ {
|
|
Zr, Zi, Tr, Ti := Zero, Zero, Zero, Zero
|
|
Cr := (2*x/w - 1.5)
|
|
Ci := (2*y/h - 1.0)
|
|
|
|
for i := 0; i < Iter && (Tr+Ti <= Limit*Limit); i++ {
|
|
Zi = 2*Zr*Zi + Ci
|
|
Zr = Tr - Ti + Cr
|
|
Tr = Zr * Zr
|
|
Ti = Zi * Zi
|
|
}
|
|
|
|
byte_acc <<= 1
|
|
if Tr+Ti <= Limit*Limit {
|
|
byte_acc |= 0x01
|
|
}
|
|
|
|
bit_num++
|
|
|
|
if bit_num == 8 {
|
|
out.WriteByte(byte_acc)
|
|
byte_acc = 0
|
|
bit_num = 0
|
|
} else if x == w-1 {
|
|
byte_acc <<= uint(8 - uint(*n)%8)
|
|
out.WriteByte(byte_acc)
|
|
byte_acc = 0
|
|
bit_num = 0
|
|
}
|
|
}
|
|
}
|
|
}
|