Graphics in Go

Presentation containing a (small) selection of my graphics experiments.

https://github.com/peterhellberg/gfx

Transcript

1. Graphics in Go
   

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2. @peterhellberg
   

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3. Interfaces!
   

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4. image.Image
   // Image is a finite rectangular
   // grid of color.Color values taken from a color model.
   type Image interface {
   // ColorModel returns the Image's color model.
   ColorModel() color.Model
   // Bounds returns the domain for which At can return non-zero color.
   // The bounds do not necessarily contain the point (0, 0).
   Bounds() Rectangle
   // At returns the color of the pixel at (x, y).
   At(x, y int) color.Color
   }
   

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5. // Model can convert any Color to one from its own color model.
   // The conversion may be lossy.
   type Model interface {
   Convert(c Color) Color
   }
   color.Model
   

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6. color.Color
   // Color can convert itself to alpha-premultiplied 16-bits per channel RGBA.
   // The conversion may be lossy.
   type Color interface {
   // RGBA returns the alpha-premultiplied red, green, blue and alpha values
   // for the color. Each value ranges within [0, 0xffff], but is represented
   // by a uint32 so that multiplying by a blend factor up to 0xffff will not
   // overflow.
   //
   // An alpha-premultiplied color component c has been scaled by alpha (a),
   // so has valid values 0 <= c <= a.
   RGBA() (r, g, b, a uint32)
   }
   

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7. draw.Image
   // Image is an image.Image with a Set method to
   change a single pixel.
   type Image interface {
   image.Image
   Set(x, y int, c color.Color)
   }
   

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8. WHAT ABOUT
   THE ELEPHANT IN 

   THE ROOM?(Shaders)
   

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9. Packages?
   

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10. go get github.com/peterhellberg/gfx
    gfx
    

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11. go get github.com/hajimehoshi/ebiten
    ebiten
    

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12. go get github.com/faiface/pixel
    pixel
    

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13. #gamedev
    #gamedev
    slack.gopher.se
    

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15. Experiments
    

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16. The XOR texture
    ⊕
    lodev.org/cgtutor/xortexture.html
    

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17. The XOR texture
    package main
    import "github.com/peterhellberg/gfx"
    func main() {
    m := gfx.NewImage(640, 360)
    gfx.EachPixel(m.Bounds(), func(x, y int) {
    c := uint8(x ^ y)
    m.Set(x, y, gfx.ColorNRGBA(c, c%192, c, 255))
    })
    gfx.SavePNG("xor.png", gfx.NewScaledImage(m, 4))
    }
    

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19. Plasma
    lodev.org/cgtutor/plasma.html
    

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20. The Plasma effect
    package main
    import (
    "github.com/peterhellberg/gfx"
    "github.com/peterhellberg/plasma"
    "github.com/peterhellberg/plasma/palette"
    )
    func main() {
    w, h, scale, seed := 2560, 1440, 64.0, 1234
    gfx.SavePNG("plasma.png", plasma.New(w, h, scale).
    Image(w, h, seed, palette.MaterialDesign700),
    )
    }
    

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22. Tunnel
    lodev.org/cgtutor/tunnel.html
    

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25. Starfield
    vendian.org/mncharity/dir3/starcolor
    

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30. DOOM fire
    fabiensanglard.net/doom_fire_psx
    

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32. Particles
    

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34. Fractals
    

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35. The Julia set
    

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37. Popcorn fractals
    paulbourke.net/fractals/popcorn
    

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39. Procedural Tree
    

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45. Domain warping
    iquilezles.org/www/articles/warp/warp.htm
    

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49. Tiles
    

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50. package main
    import "github.com/peterhellberg/gfx"
    func main() {
    gfx.SavePNG("fireflower.png", gfx.NewScaledImage(
    gfx.NewTile(palette, 8, []uint8{
    0, 1, 1, 1, 1, 1, 1, 0,
    1, 1, 2, 2, 2, 2, 1, 1,
    1, 2, 3, 3, 3, 3, 2, 1,
    1, 1, 2, 2, 2, 2, 1, 1,
    0, 1, 1, 1, 1, 1, 1, 0,
    0, 0, 0, 4, 4, 0, 0, 0,
    0, 0, 0, 4, 4, 0, 0, 0,
    4, 4, 0, 4, 4, 0, 4, 4,
    0, 4, 0, 4, 4, 0, 4, 0,
    0, 4, 4, 4, 4, 4, 4, 0,
    0, 0, 4, 4, 4, 4, 0, 0,
    }), 128))
    }
    var palette = gfx.Palette{{},
    {0xA4, 0xE8, 0xFE, 0xFF},
    {0xFD, 0xB7, 0x2C, 0xFF},
    {0xFC, 0x59, 0x29, 0xFF},
    {0x31, 0xAB, 0x4B, 0xFF},
    }
    

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51. package main
    import "github.com/peterhellberg/gfx"
    func main() {
    gfx.SavePNG("layer.png", gfx.NewScaledImage(
    gfx.NewLayer(tileset, 5, gfx.LayerData{
    4, 7, 7, 7, 4,
    5, 2, 0, 2, 6,
    5, 0, 3, 0, 6,
    5, 2, 0, 2, 6,
    4, 8, 8, 8, 4,
    }), 128),
    )
    }
    var tileset = gfx.NewTileset(
    gfx.PaletteEN4, gfx.Pt(2, 2),
    gfx.TilesetData{
    {0, 0, 0, 0}, {1, 1, 1, 1}, {2, 2, 2, 2},
    {3, 3, 3, 3}, {9, 9, 9, 9}, {1, 2, 1, 2},
    {2, 1, 2, 1}, {1, 1, 2, 2}, {2, 2, 1, 1},
    })
    

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52. Triangles
    

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53. package main
    import "github.com/peterhellberg/gfx"
    var p = gfx.PaletteFamicube
    func vx(x, y float64, n int) gfx.Vertex {
    return gfx.Vertex{Position: gfx.V(x, y), Color: p.Color(n)}
    }
    func main() {
    m := gfx.NewPaletted(640, 1080, p, p.Color(57))
    gfx.NewDrawTarget(m).MakeTriangles(&gfx.TrianglesData{
    vx(128, 12, 51), vx(12, 244, 52), vx(604, 244, 53),
    vx(12, 300, 54), vx(300, 300, 55), vx(240, 972, 56),
    }).Draw()
    gfx.SavePNG("triangles.png", m)
    }
    Triangles
    

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54. Isometric blocks
    

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55. package main
    import "github.com/peterhellberg/gfx"
    func main() {
    m := gfx.NewImage(1080, 1080)
    v := gfx.V(1.2, -1.94)
    o := gfx.BoundsCenterOrigin(m.Bounds(), v, 320)
    b := gfx.Blocks{
    {gfx.V3(0, 0, 0), gfx.V3(1, 1, 1), gfx.BlockColorRed},
    {gfx.V3(0, 1, 0), gfx.V3(1, 1, 1), gfx.BlockColorGreen},
    {gfx.V3(1, 1, 0), gfx.V3(1, 1, 1), gfx.BlockColorBlue},
    }
    b.Sort()
    b.DrawPolygons(m, o)
    gfx.SavePNG("three-blocks.png", m)
    }
    Three blocks
    

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65. SDF
    iquilezles.org/www/articles/distfunctions2d/distfunctions2d.htm
    

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66. package main
    import "github.com/peterhellberg/gfx"
    func main() {
    c := gfx.PaletteEDG36.Color
    m := gfx.NewImage(2560, 1440, c(5))
    gfx.EachImageVec(m, gfx.ZV, func(u gfx.Vec) {
    sd := gfx.SignedDistance{u}
    if d := sd.OpRepeat(gfx.V(256, 256), func(sd gfx.SignedDistance) float64 {
    return sd.OpSubtraction(sd.Circle(50), sd.Line(gfx.V(0, 0), gfx.V(64, 64)))
    }); d < 40 {
    gfx.SetVec(m, u, c(int(gfx.MathAbs(d/5))))
    }
    })
    gfx.SavePNG("sdf-repeat.png", m)
    }
    Repeat: Subtract Circle from Line
    

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68. SmoothUnion of Rectangle
    and IsoscelesTriangle
    EquilateralTriangle
    

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69. Domain coloring
    

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70. package main
    import "github.com/peterhellberg/gfx"
    const (
    w, h, fovY = 2560, 1440, 1.9
    aspect = float64(w) / float64(h)
    ahc = aspect * fovY / 2.0
    hfc = fovY / 2.0
    )
    func pixelCoordinates(px, py int) gfx.Vec {
    return gfx.V(
    ((float64(px)/(w-1))*2-1)*ahc,
    ((float64(h-py-1)/(h-1))*2-1)*hfc,
    )
    }
    Domain coloring
    func main() {
    var (
    p0 = pixelCoordinates(0, 0)
    p1 = pixelCoordinates(w-1, h-1)
    y = p0.Y
    d = gfx.V((p1.X-p0.X)/(w-1), (p1.Y-p0.Y)/(h-1))
    m = gfx.NewImage(w, h)
    )
    for py := 0; py < h; py++ {
    x := p0.X
    for px := 0; px < w; px++ {
    z := gfx.CmplxSin(1 / complex(x, y))
    c := gfx.PaletteEN4.CmplxPhaseAt(z)
    m.Set(px, py, c)
    x += d.X
    }
    y += d.Y
    }
    gfx.SavePNG("domain-coloring.png", m)
    }
    

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83. Ray Casting
    

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87. Ray Marching
    

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88. KABOOM!
    github.com/ssloy/tinykaboom
    

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89. Draw a sphere
    

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90. Diffuse shading
    

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91. Draw a pattern
    

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92. Displacement mapping
    

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93. Another implicit surface
    

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94. Pseudorandom Noise
    

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95. Fire colors
    

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97. gist.github.com/peterhellberg
    

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