Graphics in Go - Speaker Deck

Slide 1

Slide 1 text

Graphics in Go

Slide 2

Slide 2 text

@peterhellberg

Slide 3

Slide 3 text

Interfaces!

Slide 4

Slide 4 text

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 }

Slide 5

Slide 5 text

// 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

Slide 6

Slide 6 text

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) }

Slide 7

Slide 7 text

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) }

Slide 8

Slide 8 text

WHAT ABOUT THE ELEPHANT IN   THE ROOM?(Shaders)

Slide 9

Slide 9 text

Packages?

Slide 10

Slide 10 text

go get github.com/peterhellberg/gfx gfx

Slide 11

Slide 11 text

go get github.com/hajimehoshi/ebiten ebiten

Slide 12

Slide 12 text

go get github.com/faiface/pixel pixel

Slide 13

Slide 13 text

#gamedev #gamedev slack.gopher.se

Slide 14

Slide 14 text

No content

Slide 15

Slide 15 text

Experiments

Slide 16

Slide 16 text

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

Slide 17

Slide 17 text

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)) }

Slide 18

Slide 18 text

No content

Slide 19

Slide 19 text

Plasma lodev.org/cgtutor/plasma.html

Slide 20

Slide 20 text

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), ) }

Slide 21

Slide 21 text

No content

Slide 22

Slide 22 text

Tunnel lodev.org/cgtutor/tunnel.html

Slide 23

Slide 23 text

No content

Slide 24

Slide 24 text

No content

Slide 25

Slide 25 text

Starﬁeld vendian.org/mncharity/dir3/starcolor

Slide 26

Slide 26 text

No content

Slide 27

Slide 27 text

No content

Slide 28

Slide 28 text

No content

Slide 29

Slide 29 text

No content

Slide 30

Slide 30 text

DOOM ﬁre fabiensanglard.net/doom_ﬁre_psx

Slide 31

Slide 31 text

No content

Slide 32

Slide 32 text

Particles

Slide 33

Slide 33 text

No content

Slide 34

Slide 34 text

Fractals

Slide 35

Slide 35 text

The Julia set

Slide 36

Slide 36 text

No content

Slide 37

Slide 37 text

Popcorn fractals paulbourke.net/fractals/popcorn

Slide 38

Slide 38 text

No content

Slide 39

Slide 39 text

Procedural Tree

Slide 40

Slide 40 text

No content

Slide 41

Slide 41 text

No content

Slide 42

Slide 42 text

No content

Slide 43

Slide 43 text

No content

Slide 44

Slide 44 text

No content

Slide 45

Slide 45 text

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

Slide 46

Slide 46 text

No content

Slide 47

Slide 47 text

No content

Slide 48

Slide 48 text

No content

Slide 49

Slide 49 text

Tiles

Slide 50

Slide 50 text

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}, }

Slide 51

Slide 51 text

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}, })

Slide 52

Slide 52 text

Triangles

Slide 53

Slide 53 text

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

Slide 54

Slide 54 text

Isometric blocks

Slide 55

Slide 55 text

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

Slide 56

Slide 56 text

No content

Slide 57

Slide 57 text

No content

Slide 58

Slide 58 text

No content

Slide 59

Slide 59 text

No content

Slide 60

Slide 60 text

No content

Slide 61

Slide 61 text

No content

Slide 62

Slide 62 text

No content

Slide 63

Slide 63 text

No content

Slide 64

Slide 64 text

No content

Slide 65

Slide 65 text

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

Slide 66

Slide 66 text

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

Slide 67

Slide 67 text

No content

Slide 68

Slide 68 text

SmoothUnion of Rectangle and IsoscelesTriangle EquilateralTriangle

Slide 69

Slide 69 text

Domain coloring

Slide 70

Slide 70 text

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) }