golangでマンデンブロ集合の エモい?gif画像作成を高速化する

Transcript

1. HPMBOHͰϚϯσϯϒϩू߹ͷ
   ΤϞ͍ HJGը૾࡞੒Λߴ଎Խ͢Δ
2. ࣗݾ঺հ IUUQTHJUIVCDPNUX
   ࢓ࣄ
   ීஈ͸SBJMTΛ࢖ͬͯϚΠΫϩαʔϏεͷҰ෦Λ
   
   
   
   
   
   
   
   
   
   ͔͔ͤͤ։ൃ͍ͯ͠·͢ ࣌ʑ1ZUIPO
   (Pྺ
   ϲ݄ͪΐ͍ 
   d
   
3. എܠ ɾϓϩάϥϛϯάݴޠ(PΛಡΈਐΊΔաఔͰϚϯσϯϒϧू߹ͷ
   
   
   
   
   ը૾Λ࡞੒͢ΔνϡʔτϦΞϧΛߦ͏ Ҿ਺ʹΑΓܗ͕มΘΔ ɻ
   ɾHJGը૾ͷ࡞੒ํ๏ΛֶͿɻ
   
   
   
   Ϛϯσϯϒϧू߹ͷมԽΛHJGͰݟͨ͘ͳΔ /FX ͜Ε ͜ΜͳΜ
4. ࡞ͬͯݟͨ var powArg float64 func init() { flag.Float64Var(&powArg,"pow", 2.0, "ext) ./go-gifmandelbrot -pow=2.0") } func main() { flag.Parse() anim := gif.GIF{LoopCount: nframes} for pow := 1.0; pow < powArg; pow += 0.02 { draw(&anim, pow) } f, _ := os.OpenFile("out.gif", os.O_WRONLY|os.O_CREATE, 0600) defer f.Close() gif.EncodeAll(f, &anim) } func draw(anim *gif.GIF, pow float64) { rect := image.Rect(0, 0, width, height) img := image.NewPaletted(rect, palette) for py := 0; py < height; py++ { y := float64(py)/height*(ymax-ymin) + ymin for px := 0; px < width; px++ { x := float64(px)/width*(xmax-xmin) + xmin z := complex(x, y) // ը૾ͷ఺(px, py)͸ෳૉ਺஋zΛද͍ͯ͠Δɻ img.Set(px, py, mandelbrot(z, pow)) } } anim.Delay = append(anim.Delay, delay) anim.Image = append(anim.Image, img) } func mandelbrot(z complex128, pow float64) color.Color { const iterations = 200 const contrast = 15 var v complex128 = 0 for n := uint8(0); n < iterations; n++ { v = cmplx.Pow(v, complex(pow, 0)) + z if cmplx.Abs(v) > 2 { return color.Gray{Y: 255 - contrast*n} } } return color.Black }
5. ݁Ռ ˢ1%'൛ͷࢿྉͰ͸ಈ͖·ͤΜ
6. ݁Ռ ͍͍ײ͡ʹಈ͍͍ͯΔʂʂײಈ
7. HPʹஔ͚ΔHJGը૾ͷ࡞Γํ func main() { flag.Parse() anim := gif.GIF{LoopCount: nframes} for pow := 1.0; pow < powArg; pow += 0.02 { draw(&anim, pow) } f, _ := os.OpenFile("out.gif", os.O_WRONLY|os.O_CREATE, 0600) defer f.Close() gif.EncodeAll(f, &anim) } func draw(anim *gif.GIF, pow float64) { rect := image.Rect(0, 0, width, height) img := image.NewPaletted(rect, palette) (ུ) anim.Delay = append(anim.Delay, delay) anim.Image = append(anim.Image, img) } (*'*NBHFʹ JNBHF1MBUUFEΛBQQFOE͍͖ͯ͠
   &ODPEF"MM͢Δ͜ͱʹΑΓੜ੒Ͱ͖Δɻ
8. ݁Ռ ͡Ό͋HJGը૾Λ࡞੒͢Δͷʹ
   ͲΕ͚͔͔ͩΔͷ͔ɾɾɾ
9. ݁Ռ HJGը૾͕ੜ੒͞ΕΔ·Ͱʹ͔͔ͬͨ࣌ؒ
   
   
   
   
   
   NT
   UJNFͰͷࢉग़
10. ݁Ռ ΋ͷ͘͢͝஗͍ ମײ
11. ݪҼ func draw(anim *gif.GIF, pow float64) { rect := image.Rect(0, 0, width, height) img := image.NewPaletted(rect, palette) for py := 0; py < height; py++ { y := float64(py)/height*(ymax-ymin) + ymin for px := 0; px < width; px++ { x := float64(px)/width*(xmax-xmin) + xmin z := complex(x, y) // ը૾ͷ఺(px, py)͸ෳૉ਺஋zΛද͍ͯ͠Δɻ img.Set(px, py, mandelbrot(z, pow)) } } anim.Delay = append(anim.Delay, delay) anim.Image = append(anim.Image, img) } GPSͰωετ͞Εͨ௚ྻͳը૾ͷ఺ͷϓϩοτ
12. func draw(anim *gif.GIF, pow float64) { rect := image.Rect(0, 0, width, height) img := image.NewPaletted(rect, palette) for py := 0; py < height; py++ { y := float64(py)/height*(ymax-ymin) + ymin for px := 0; px < width; px++ { x := float64(px)/width*(xmax-xmin) + xmin z := complex(x, y) // ը૾ͷ఺(px, py)͸ෳૉ਺஋zΛද͍ͯ͠Δɻ img.Set(px, py, mandelbrot(z, pow)) } } anim.Delay = append(anim.Delay, delay) anim.Image = append(anim.Image, img) } HPSPVUJOFΛ࢖͑͹ૣ͘ͳΔͷͰ͸ʁ
13. վળ func draw(anim *gif.GIF, pow float64) { rect := image.Rect(0, 0, width, height) img := image.NewPaletted(rect, palette) var wg sync.WaitGroup for py := 0; py < height; py++ { for px := 0; px < width; px++ { x := px y := py wg.Add(1) go func() { plot(img, x, y, pow) wg.Done() }() } } wg.Wait() anim.Delay = append(anim.Delay, delay) anim.Image = append(anim.Image, img) } func plot(img *image.Paletted, px int, py int, pow float64) { y := float64(py)/height*(ymax-ymin) + ymin x := float64(px)/width*(xmax-xmin) + xmin z := complex(x, y) // ը૾ͷ఺(px, py)͸ෳૉ਺஋zΛද͍ͯ͠Δɻ img.Set(px, py, mandelbrot(z, pow)) } HPSPVUJOFʹΑΔฒߦԽ ฒྻͰ͸ͳ͍
14. վળ func draw(anim *gif.GIF, pow float64) { (ུ) var wg sync.WaitGroup for py := 0; py < height; py++ { for px := 0; px < width; px++ { x := px y := py wg.Add(1) go func() { plot(img, x, y, pow) wg.Done() }() } } wg.Wait() (ུ) } func plot(img *image.Paletted, px int, py int, pow float64) { (ུ) // ը૾ͷ఺(px, py)͸ෳૉ਺஋zΛද͍ͯ͠Δɻ img.Set(px, py, mandelbrot(z, pow)) } 
    JNH4FU ʜ ͸GPSͷ֤MPPQͰผͷ࠲ඪͷ఺Λϓϩοτ͍ͯ͠Δ
    
    ֤఺ͷϓϩοτॱংʹӨڹ͞Εͳ͍
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    HPSPVUJOF͕ద༻͠΍͍͢ʂʂʂ
15. func draw(anim *gif.GIF, pow float64) { (ུ) var wg sync.WaitGroup for py := 0; py < height; py++ { for px := 0; px < width; px++ { x := px y := py wg.Add(1) go func() { plot(img, x, y, pow) wg.Done() }() } } wg.Wait() (ུ) } func plot(img *image.Paletted, px int, py int, pow float64) { (ུ) // ը૾ͷ఺(px, py)͸ෳૉ਺஋zΛද͍ͯ͠Δɻ img.Set(px, py, mandelbrot(z, pow)) } શͯͷ֤఺ͷϓϩοτॲཧͷHPSPVUJOF͕શͯऴྃ͢ΔͷΛ
    ଴ͨͳ͍ͱ͍͚ͳ͍
    
    
    
    
    
    
    TZOD8BJU(SPVQ
    Λ࢖ͬͯશHPSPVUJOFͷऴྃΛ଴ͭ վળ
16. վળ func draw(anim *gif.GIF, pow float64) { (ུ) var wg sync.WaitGroup for py := 0; py < height; py++ { for px := 0; px < width; px++ { x := px y := py wg.Add(1) go func() { plot(img, x, y, pow) wg.Done() }() } } wg.Wait() (ུ) } func plot(img *image.Paletted, px int, py int, pow float64) { (ུ) // ը૾ͷ఺(px, py)͸ෳૉ਺஋zΛද͍ͯ͠Δɻ img.Set(px, py, mandelbrot(z, pow)) } XH"EE  ͸HPSPVUJOFͷ֎ʹॻ͘ඞཁ͕͋Δɻ
17. վળ ࠷ऴతͳHPSVUJOFద༻ޙͷ଎౓
18. HJGը૾͕ੜ੒͞ΕΔ·Ͱʹ͔͔ͬͨ࣌ؒ UJNFͰͷࢉग़
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    CFGPSF
    NT
    
    
    
    
    
    
    
    
    
    
    BGUFS
    
    
    
    NT վળͦͷ
19. ଎౓Λେ෯ʹվળ
    
    CFGPSF
    NT
    
    BGUFS
    
    
    
    NT վળͦͷ
20. ༨ஊ func main() { flag.Parse() anim := gif.GIF{LoopCount: nframes} for pow := 1.0; pow < powArg; pow += 0.02 { draw(&anim, pow) } f, _ := os.OpenFile("out.gif", os.O_WRONLY|os.O_CREATE, 0600) defer f.Close() gif.EncodeAll(f, &anim) } func draw(anim *gif.GIF, pow float64) { rect := image.Rect(0, 0, width, height) img := image.NewPaletted(rect, palette) (ུ) anim.Delay = append(anim.Delay, delay) anim.Image = append(anim.Image, img) } ESBX΋GPS࢖ͬͯΔ͠ɺͬͪ͜΋HPSPVUJOFͰ
    ߴ଎Ͱ͖Δ͠ΐʁ
21. ༨ஊ݁Ռ HPSPVUJOFԽ͸Ͱ͖ͨɺɺɺ݁Ռ΋ಉ͡ɺɺɺ
    Ͱ΋ૣ͘ͳΒͣɻɻ
    ˠ
    Ͳ͏ʹ͔͜͏ʹ͔ૣ͘͠Α͏ͱͯ͢͠Δ΋
    ɹ
    Ұ޲ʹ଎౓͸ૣ͘ͳΒͣɺɺɺ
    ˠ
    ఘΊΔ
22. ɾॱংΛߟྀ͢Δඞཁͷͳ͍ॲཧΛฒߦʹHPSPVUJOFԽ͢Δͱ
    
    
    ౰વ શମͷॲཧ͕࣌ؒૣ͘ͳΔ
    ɾݸਓతʹࢥ͏HPSPVUJOFΛదԠ͢Δ·ͰͷྲྀΕ
    
    
    
    
    ۪௚ʹॲཧΛॻ͘ɻ
    
    
    
    
    HPSPVUJOF
    ΛదԠ͠΍͍͢Α͏ϦϑΝΫλϦϯά͢Δɻ
    
    
    
    
    
    
    
    
    
    ͜ͷࡍॲཧ͕ؔ਺ɺϝιουͱͯ͠੾Γग़ͤΔͱHPSPVUJOF
    
    
    
    
    
    
    
    
    
    ʹ͠΍͍͢
    
    
    
    
    HPSPVUJOFԽ͢Δ ݁࿦
23. ࠷ॳ͔ΒHPSPVUJOF͋Γ͖ͰίʔσΟϯά͢ΔΑΓɺ
    ී௨ʹίʔσΟϯάͨ͠ޙʹϦϑΝΫλϦϯά͠ɺ
    Ͳͷ෦෼Ͱ͋Ε͹HPSPVUJOFͱͯ͠੾Γग़ͤΔ͔ɺɺ
    Ͳͷ෦෼Ͱ͋Ε͹ฒߦʹ࣮ߦͯ͠΋݁ՌʹӨڹ͕ग़ͳ͍͔ɺ
    ͱ͍͏෩ʹߟ͑ͨ΄͏͕HPSPVUJOFΛద༻͠΍͍͢ɻ ײ૝
24. HPSPVUJOFΛ࢖༻͢Ε͹ૣ͘ͳΔɺɺ
    ͨͩ͠ͳΜͰ΋͔ΜͰ΋ద༻͢Ε͹͍͍ͯ΋Μ͡Όͳ͍ɻ
    ˞ݸਓͷײ૝Ͱ͋Γɺ࣮ྗʹΑΓ·͢ɻ ͓·͚
25. ͝੩ௌ͋Γ͕ͱ͏͍͟͝·ͨ͠