zorldo

commit c909df6dd91353320591b79101cb0c7bc0af897b
parent c386d72caaf5e21a93e4d5be7d6397332a72b723
Author: bsandro <brian.drosan@gmail.com>
Date:   Thu,  7 Oct 2021 01:52:56 +0300

Camera as a separate structure

Diffstat:
A
camera.go
 | 
31
+++++++++++++++++++++++++++++++
M
main.go
 | 
22
++++++++++++----------

2 files changed, 43 insertions(+), 10 deletions(-)
diff --git a/camera.go b/camera.go
@@ -0,0 +1,31 @@
+package main
+
+import (
+	"math"
+)
+
+type Camera struct {
+	x, y                float64
+	maxWidth, maxHeight float64
+}
+
+func (cam *Camera) Init(maxWidth, maxHeight float64) {
+	cam.maxWidth = maxWidth
+	cam.maxHeight = maxHeight
+}
+
+func (cam *Camera) ChangeX(diff float64) {
+	if diff < 0 {
+		cam.x = math.Max(cam.x+diff, 0)
+	} else {
+		cam.x = math.Min(cam.x+diff, cam.maxWidth)
+	}
+}
+
+func (cam *Camera) ChangeY(diff float64) {
+	if diff < 0 {
+		cam.y = math.Max(cam.y+diff, 0)
+	} else {
+		cam.y = math.Min(cam.y+diff, cam.maxHeight)
+	}
+}
diff --git a/main.go b/main.go
@@ -8,21 +8,21 @@ import (
 	"github.com/hajimehoshi/ebiten/v2/inpututil"
 	_ "image/png"
 	"log"
-	"math"
 	"os"
 )
 
 const (
-	screenW       = 1024
-	screenH       = 768
+	screenW       = 1280
+	screenH       = 480
 	magnification = 2
+	cameraStep    = 10
 )
 
 type Game struct {
 	Inited      bool
 	Map         *Gamemap
 	PressedKeys []ebiten.Key
-	ScreenPos   struct{ x, y float64 }
+	Cam         Camera
 }
 
 func (g *Game) Init() error {
@@ -37,6 +37,8 @@ func (g *Game) Init() error {
 		return err
 	}
 
+	g.Cam.Init(g.Map.RealWidth-screenW/magnification, g.Map.RealHeight-screenH/magnification)
+
 	return nil
 }
 
@@ -45,13 +47,13 @@ func (g *Game) Update() error {
 	for _, key := range g.PressedKeys {
 		switch key {
 		case ebiten.KeyArrowLeft:
-			g.ScreenPos.x = math.Max(g.ScreenPos.x-10, 0)
+			g.Cam.ChangeX(-cameraStep)
 		case ebiten.KeyArrowRight:
-			g.ScreenPos.x = math.Min(g.ScreenPos.x+10, g.Map.RealWidth-screenW/magnification)
+			g.Cam.ChangeX(cameraStep)
 		case ebiten.KeyArrowUp:
-			g.ScreenPos.y = math.Max(g.ScreenPos.y-10, 0)
+			g.Cam.ChangeY(-cameraStep)
 		case ebiten.KeyArrowDown:
-			g.ScreenPos.y = math.Min(g.ScreenPos.y+10, g.Map.RealHeight-screenH/magnification)
+			g.Cam.ChangeY(cameraStep)
 		case ebiten.KeyQ:
 			os.Exit(0)
 		default:
@@ -65,11 +67,11 @@ func (g *Game) Draw(screen *ebiten.Image) {
 	for _, layer := range g.Map.Layers {
 		for _, t := range layer.Tiles {
 			opts := *t.Options
-			opts.GeoM.Translate(-g.ScreenPos.x, -g.ScreenPos.y)
+			opts.GeoM.Translate(-g.Cam.x, -g.Cam.y)
 			screen.DrawImage(t.Image, &opts)
 		}
 	}
-	ebitenutil.DebugPrint(screen, fmt.Sprintf("TPS: %0.2f, screen: %v", ebiten.CurrentTPS(), g.ScreenPos))
+	ebitenutil.DebugPrint(screen, fmt.Sprintf("TPS: %0.2f, screen: %v", ebiten.CurrentTPS(), g.Cam))
 }
 
 func (g *Game) Layout(outsideWidth, outsideHeight int) (screenWidth, screenHeight int) {