func (a *app) Run() {
// If updates start
const maxMultipleUpdates = 6
lastTime := time.Now().UnixNano()
for len(a.states) > 0 {
currentTime := time.Now().UnixNano()
if currentTime-lastTime < a.nanosecondsPerFrame {
// Avoid busy waiting and take short naps if ahead of schedule.
// XXX: Is this a good thing?
time.Sleep(10e6)
continue
}
// If things get slow, tell Update multiple frames have elapsed.
nUpdates := (currentTime - lastTime) / a.nanosecondsPerFrame
if nUpdates < 1 {
nUpdates = 1
}
if nUpdates > maxMultipleUpdates {
nUpdates = maxMultipleUpdates
}
a.TopState().Draw()
gfx.BlitX2(sdl.Frame(), sdl.Video())
sdl.Flip()
a.TopState().Update(nUpdates * a.nanosecondsPerFrame)
lastTime += nUpdates * a.nanosecondsPerFrame
}
sdl.Stop()
}
func (h *Hud) Draw(bounds image.Rectangle) {
h.update()
sdl.Frame().SetClipRect(bounds)
defer sdl.Frame().ClearClipRect()
style := util.TextStyle().ForeColor(gfx.Khaki).Edge(typography.Round)
lines := []string{}
for _, str := range h.msgs {
for _, line := range typography.SplitToLines(util.TextStyle(), str, float64(bounds.Dx())) {
lines = append(lines, line)
}
}
for lineY, str := range lines {
pos := bounds.Min.Add(image.Pt(0, (lineY+1)*int(style.LineHeight())))
style.Render(str, pos)
}
h.drawHealth(image.Rectangle{image.Pt(bounds.Min.X, bounds.Max.Y-8), bounds.Max})
}
func BenchmarkTruecolorBlit(b *testing.B) {
b.StopTimer()
sdl.Run(320, 240)
defer sdl.Stop()
surf := unpaletted()
b.StartTimer()
for i := 0; i < b.N; i++ {
for y := 0; y < 30; y++ {
for x := 0; x < 40; x++ {
surf.Blit(surf.Bounds(), x*8, y*8, sdl.Frame())
}
}
sdl.Flip()
}
b.StopTimer()
}
// Beam generates a projectile beam effect in the game world.
func (f *Fx) Beam(origin space.Location, dir image.Point, length int, kind BeamKind) {
// Make a footprint for the beam shape.
shape := []image.Point{image.Pt(0, 0)}
for i := 0; i < length; i++ {
shape = append(shape, shape[len(shape)-1].Add(dir))
}
footprint := space.FootprintFromPoints(f.world.Manifold, origin, shape)
screenVec := util.ChartToScreen(shape[len(shape)-1])
// TODO: Different beam types.
f.anim.Add(
anim.Func(func(t int64, offset image.Point) {
gfx.Line(
sdl.Frame(),
offset.Add(util.HalfTile),
offset.Add(util.HalfTile).Add(screenVec),
gfx.LerpCol(gfx.Gold, gfx.Black, float64(t)/float64(.5e9)))
}), footprint, .2e9)
}
func (s *Style) Render(line string, pos image.Point) {
s.RenderOn(sdl.Frame(), line, pos)
}
func (gs *game) Draw() {
sdl.Frame().Clear(gfx.Black)
gs.view.Draw(image.Rect(0, 0, 320, 240))
gs.hud.Draw(image.Rect(0, 0, 320, 240))
}