go-opengl-pixel/gfx/gfx.go

319 lines
7.0 KiB
Go

package gfx
import (
"fmt"
"image"
_ "image/png"
"math"
"math/rand"
"os"
"relay/game"
"time"
"github.com/faiface/pixel"
"github.com/faiface/pixel/imdraw"
"github.com/faiface/pixel/pixelgl"
"golang.org/x/image/colornames"
)
func RenderLoop(w *pixelgl.Window, s game.State, sOld game.State, stateC <-chan game.State, sb *SpriteBank) {
var (
frames = 0
second = time.Tick(time.Second)
rs = renderState{
Frames: 15,
}
)
for !w.Closed() {
if rs.Frame == rs.Frames {
select {
case ss := <-stateC:
sOld = s
s = ss
rs.Frame = 0
default:
}
}
rs = Render(rs, sOld, s, w, *sb)
w.Update()
frames++
select {
case <-second:
w.SetTitle(fmt.Sprintf("%s | FPS: %d", "Relay", frames))
frames = 0
default:
}
}
}
type renderState struct {
Frames int
Frame int
}
type context struct {
sOld game.State
sNew game.State
tween float64
w *pixelgl.Window
}
type SpriteBank struct {
racer pixel.Picture
obstacle pixel.Picture
derelict pixel.Picture
}
func NewSpriteBank() (*SpriteBank, error) {
var sb SpriteBank
for file, field := range map[string]*pixel.Picture{
"shuttle.png": &sb.racer,
"rock.png": &sb.obstacle,
"derelict.png": &sb.derelict,
} {
p, err := loadPicture(file)
if err != nil {
return nil, fmt.Errorf("load picture %q: %w", file, err)
}
*field = p
}
return &sb, nil
}
func loadPicture(path string) (pixel.Picture, error) {
file, err := os.Open(path)
if err != nil {
return nil, err
}
defer file.Close()
img, _, err := image.Decode(file)
if err != nil {
return nil, err
}
return pixel.PictureDataFromImage(img), nil
}
func Render(rs renderState, sOld, sNew game.State, w *pixelgl.Window, sb SpriteBank) renderState {
bgBatch := pixel.NewBatch(new(pixel.TrianglesData), nil)
renderBackground(w, bgBatch)
oBatch := pixel.NewBatch(new(pixel.TrianglesData), sb.obstacle)
renderObstacles(sNew.Obstacles, w, oBatch, sb.obstacle)
oBatch.Draw(w)
dBatch := pixel.NewBatch(new(pixel.TrianglesData), sb.derelict)
renderObstacles(sNew.Derelicts, w, dBatch, sb.derelict)
dBatch.Draw(w)
sBatch := pixel.NewBatch(new(pixel.TrianglesData), nil)
renderSpawnPoints(sBatch, sNew.SpawnPoints, w.Bounds())
sBatch.Draw(w)
ctx := context{
sOld: sOld,
sNew: sNew,
tween: float64(rs.Frame) / float64(rs.Frames),
w: w,
}
rBatch := pixel.NewBatch(new(pixel.TrianglesData), sb.racer)
renderRacers(ctx, rBatch, sb.racer)
rBatch.Draw(w)
if rs.Frame < rs.Frames {
rs.Frame++
}
return rs
}
var stars []pixel.Vec
func renderBackground(w *pixelgl.Window, batch *pixel.Batch) {
w.Clear(colornames.Black)
batch.Clear()
if len(stars) == 0 {
const numStars = 100
for i := 0; i < numStars; i++ {
stars = append(stars, pixel.Vec{
X: rand.Float64() * w.Bounds().W(),
Y: rand.Float64() * w.Bounds().H(),
})
}
}
im := imdraw.New(nil)
im.Color = colornames.White
for _, star := range stars {
im.Push(star)
im.Clear()
}
im.Circle(2, 0)
im.Draw(batch)
batch.Draw(w)
}
func renderRacers(ctx context, batch *pixel.Batch, pic pixel.Picture) {
for i, t := range ctx.sNew.Teams {
c := teamColors[i]
for j, racer := range t.Racers {
oldRacer := ctx.sOld.Teams[i].Racers[j]
renderRacer(ctx, batch, oldRacer, racer, racer.ID == ctx.sOld.Teams[i].Baton.HolderID, c, pic)
}
oldHolder, newHolder := game.ActiveRacer(ctx.sOld.Teams[i]), game.ActiveRacer(ctx.sNew.Teams[i])
oldPos := lanePos(oldHolder.Position.Pos, oldHolder.Position.Lane, racerWidth, ctx.w.Bounds())
newPos := lanePos(newHolder.Position.Pos, newHolder.Position.Lane, racerWidth, ctx.w.Bounds())
pos := pixel.Vec{
X: oldPos.X + ctx.tween*(newPos.X-oldPos.X),
Y: oldPos.Y + ctx.tween*(newPos.Y-oldPos.Y),
}
renderBaton(pos, batch)
}
}
func renderRacer(ctx context, batch *pixel.Batch, oldRacer, racer game.Racer, active bool, c pixel.RGBA, pic pixel.Picture) {
oldPos := lanePos(oldRacer.Position.Pos, oldRacer.Position.Lane, racerWidth, ctx.w.Bounds())
newPos := lanePos(racer.Position.Pos, racer.Position.Lane, racerWidth, ctx.w.Bounds())
pos := pixel.Vec{
X: oldPos.X + ctx.tween*(newPos.X-oldPos.X),
Y: oldPos.Y + ctx.tween*(newPos.Y-oldPos.Y),
}
bounds := pic.Bounds()
if active {
renderProjection(ctx, batch, c, bounds, racer.Kinetics, pos, newPos)
}
sprite := pixel.NewSprite(pic, bounds)
sprite.DrawColorMask(batch, pixel.IM.Moved(pos).ScaledXY(pos, pixel.Vec{1.7, 1.7}), c)
renderFuelGuage(batch, pos, racer.Battery)
}
func renderFuelGuage(b *pixel.Batch, pos pixel.Vec, batt game.Battery) {
w := 3.0
im1, im2 := imdraw.New(nil), imdraw.New(nil)
im1.Color = colornames.Yellow
im2.Color = colornames.Yellow
for i := 0; i < batt.Capacity; i++ {
pos := pos
pos.X -= racerWidth
pos.Y -= racerWidth + w*2
pos.X += (w * 2) * float64(i)
if i >= batt.Charge {
im2.Push(pos)
} else {
im1.Push(pos)
}
}
im1.Circle(w, 0)
im2.Circle(w, 1)
im1.Draw(b)
im2.Draw(b)
}
func renderProjection(ctx context, b *pixel.Batch, c pixel.RGBA, bounds pixel.Rect, k game.Kinetics, pos, newPos pixel.Vec) {
im := imdraw.New(nil)
projC := c
alpha := 0.25
projC.R *= alpha
projC.G *= alpha
projC.B *= alpha
projC.A = alpha
im.Color = projC
w := bounds.W() * 0.65
ll := pixel.Vec{
X: pos.X + w,
Y: pos.Y - w,
}
ur := pixel.Vec{
X: pos.X + w*float64(k.V+1),
Y: pos.Y + w,
}
if ctx.tween < 1 {
ur.X = math.Min(ur.X, newPos.X+racerWidth)
}
ur.X = math.Max(ur.X, ll.X)
im.Push(ll)
im.Push(ur)
im.Rectangle(0)
im.Draw(b)
}
func renderBaton(pos pixel.Vec, b *pixel.Batch) {
im := imdraw.New(nil)
im.Color = colornames.Bisque
im.Push(pos)
im.Clear()
im.Circle(batonWidth, 3)
im.Draw(b)
}
func lanePos(pos, lane int, width float64, bounds pixel.Rect) pixel.Vec {
hOffset := bounds.Size().X / game.Steps
vOffset := bounds.Size().Y / (game.NumLanes + 1)
return pixel.V(bounds.Min.X+width/2+float64(pos)*hOffset,
bounds.Min.Y+float64(lane+1)*vOffset)
}
func renderObstacles(os []game.Obstacle, w *pixelgl.Window, batch *pixel.Batch, pic pixel.Picture) {
b := w.Bounds()
im := imdraw.New(nil)
for _, o := range os {
pos := lanePos(o.Position.Pos, o.Position.Lane, racerWidth, b)
im.Push(pos)
sprite := pixel.NewSprite(pic, pic.Bounds())
sprite.Draw(batch, pixel.IM.Moved(pos))
}
im.Draw(batch)
}
func renderSpawnPoints(b *pixel.Batch, sps map[int]game.SpawnPoint, bounds pixel.Rect) {
im := imdraw.New(nil)
for _, sp := range sps {
c := teamColors[sp.TeamID]
c.R *= 0.5
c.G *= 0.5
c.B *= 0.5
im.Color = c
pos := lanePos(sp.Pos.Pos, sp.Pos.Lane, racerWidth, bounds)
im.Push(pos)
im.Circle(float64(racerWidth)*1.5, 3)
}
im.Draw(b)
}
var teamColors = map[int]pixel.RGBA{
0: pixel.ToRGBA(colornames.Palevioletred),
1: pixel.ToRGBA(colornames.Lime),
2: pixel.ToRGBA(colornames.Cornflowerblue),
3: pixel.ToRGBA(colornames.Magenta),
4: pixel.ToRGBA(colornames.Cyan),
5: pixel.ToRGBA(colornames.Yellow),
6: pixel.ToRGBA(colornames.Blueviolet),
7: pixel.ToRGBA(colornames.Orange),
8: pixel.ToRGBA(colornames.Coral),
}
const (
racerWidth float64 = 17
batonWidth float64 = 12
)