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Diffstat (limited to 'test/bench/shootout/mandelbrot.go')
-rw-r--r-- | test/bench/shootout/mandelbrot.go | 95 |
1 files changed, 95 insertions, 0 deletions
diff --git a/test/bench/shootout/mandelbrot.go b/test/bench/shootout/mandelbrot.go new file mode 100644 index 000000000..1f9fbfd3d --- /dev/null +++ b/test/bench/shootout/mandelbrot.go @@ -0,0 +1,95 @@ +/* +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 := *n + h := *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", w, h) + + for y := 0; y < h; y++ { + for x := 0; x < w; x++ { + Zr, Zi, Tr, Ti := Zero, Zero, Zero, Zero + Cr := (2*float64(x)/float64(w) - 1.5) + Ci := (2*float64(y)/float64(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 - w%8) + out.WriteByte(byte_acc) + byte_acc = 0 + bit_num = 0 + } + } + } +} |