tins2020/fpsrenderer.go
2020-05-09 15:32:43 +02:00

52 lines
966 B
Go

package tins2020
import (
"fmt"
"time"
"github.com/veandco/go-sdl2/sdl"
)
type FPS struct {
ControlBase
start time.Time
stamp time.Duration
slot int
ticks []int
total int
}
func (f *FPS) Init(*Context) error {
f.start = time.Now()
f.stamp = 0
f.ticks = make([]int, 51)
return nil
}
func (f *FPS) Render(ctx *Context) {
elapsed := time.Since(f.start)
stamp := elapsed / (20 * time.Millisecond)
for f.stamp < stamp {
f.total += f.ticks[f.slot]
f.slot = (f.slot + 1) % len(f.ticks)
f.total -= f.ticks[f.slot]
f.ticks[f.slot] = 0
f.stamp++
}
f.ticks[f.slot]++
font := ctx.Fonts.Font("debug")
surface, err := font.RenderUTF8Solid(fmt.Sprintf("FPS: %d", f.total), sdl.Color{R: 255, G: 255, B: 255, A: 255})
if err != nil {
return
}
defer surface.Free()
texture, err := NewTextureFromSurface(ctx.Renderer, surface)
if err != nil {
return
}
defer texture.Destroy()
texture.Copy(ctx.Renderer, texture.RectOffset(Pt(5, 5)))
}