tins2020/gamecontrols.go

package tins2020

import (
	"log"

	"github.com/veandco/go-sdl2/sdl"
)

type GameControls struct {
	ControlBase

	menu    ButtonBar
	flowers ButtonBar
}

type ButtonBar struct {
	Top     int32
	Left    int32
	Bottom  int32
	Hover   int
	Buttons []Button
}

type Button struct {
	Icon     string
	Disabled string

	IsDisabled bool
}

const buttonBarWidth = 96

func (b *ButtonBar) Handle(ctx *Context, event sdl.Event) {
	switch e := event.(type) {
	case *sdl.MouseMotionEvent:
		if e.X > b.Left && e.X < b.Left+buttonBarWidth {
			button := int(e.Y-b.Top) / buttonBarWidth
			if button < 0 || button >= len(b.Buttons) || b.Buttons[button].IsDisabled {
				button = -1
			}
			b.Hover = button
		} else {
			b.Hover = -1
		}
	}
}

func (b *ButtonBar) Render(ctx *Context) {
	ctx.Renderer.FillRect(&sdl.Rect{X: b.Left, Y: b.Top, W: b.Left + buttonBarWidth, H: b.Bottom})
	texture := func(b Button) *Texture {
		if b.IsDisabled {
			texture := ctx.Textures.Texture(b.Disabled)
			if texture != nil {
				return texture
			}
		}
		return ctx.Textures.Texture(b.Icon)
	}
	hoverTexture := ctx.Textures.Texture("game-control-hover")
	for i, button := range b.Buttons {
		pos := Pt(b.Left, b.Top+int32(i)*buttonBarWidth)
		texture := texture(button)
		texture.Copy(ctx.Renderer, &sdl.Rect{X: pos.X, Y: pos.Y, W: buttonBarWidth, H: buttonBarWidth})
		if b.Hover == i {
			hoverTexture.Copy(ctx.Renderer, hoverTexture.RectOffset(pos))
		}
	}
}

func NewGameControls() *GameControls {
	return &GameControls{}
}

func (c *GameControls) Init(ctx *Context) error {
	c.flowers.Hover = -1
	c.flowers.Buttons = []Button{
		Button{Icon: "flower-poppy-1", Disabled: "flower-poppy-disabled"},
		Button{Icon: "flower-red-c-1", Disabled: "flower-red-c-disabled", IsDisabled: true},
	}
	return c.updateBarPositions(ctx)
}

func (c *GameControls) Handle(ctx *Context, event sdl.Event) {
	c.menu.Handle(ctx, event)
	c.flowers.Handle(ctx, event)

	switch e := event.(type) {
	case *sdl.WindowEvent:
		switch e.Event {
		case sdl.WINDOWEVENT_RESIZED:
			err := c.updateBarPositions(ctx)
			if err != nil {
				log.Fatal(err)
			}
		}
	}
}

func (c *GameControls) Render(ctx *Context) {
	ctx.Renderer.SetDrawColor(74, 198, 154, 255)
	c.menu.Render(ctx)
	c.flowers.Render(ctx)
}

func (c *GameControls) updateBarPositions(ctx *Context) error {
	w, h, err := ctx.Renderer.GetOutputSize()
	if err != nil {
		return err
	}
	c.menu.Top, c.menu.Left, c.menu.Bottom = 0, 0, h
	c.flowers.Top, c.flowers.Left, c.flowers.Bottom = 0, w-buttonBarWidth, h
	return nil
}