From 1f1c464f84a169ea5146d360ae6b1211d8a7074f Mon Sep 17 00:00:00 2001
From: davidovski <david@davidovski.xyz>
Date: Sun, 21 Apr 2024 13:47:41 +0100
Subject: Initial Commit

---
 tilemap.go | 118 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 118 insertions(+)
 create mode 100644 tilemap.go

(limited to 'tilemap.go')

diff --git a/tilemap.go b/tilemap.go
new file mode 100644
index 0000000..281e76a
--- /dev/null
+++ b/tilemap.go
@@ -0,0 +1,118 @@
+package main
+
+import (
+    "github.com/hajimehoshi/ebiten/v2"
+    "log"
+    "image"
+    _ "image/png"
+	"github.com/hajimehoshi/ebiten/v2/ebitenutil"
+
+)
+
+type Tilemap struct {
+    tilesImage *ebiten.Image
+    surface *ebiten.Image
+    mapWidth int
+    tileSize int
+    layers [][]int
+    collisions []image.Rectangle
+}
+
+
+// take in map coord and make it real life coord
+func (t *Tilemap) Translate(x, y int) (int, int) {
+    return x * t.tileSize, y*t.tileSize
+}
+
+func (* Tilemap) Update() error {
+	return nil
+}
+
+func (tm * Tilemap) Draw(screen *ebiten.Image) {
+}
+
+func (tm *Tilemap) UpdateSurface() {
+    w := tm.tilesImage.Bounds().Dx()
+	tileXCount := w / tileSize
+
+	// Draw each tile with each DrawImage call.
+	// As the source images of all DrawImage calls are always same,
+	// this rendering is done very efficiently.
+	// For more detail, see https://pkg.go.dev/github.com/hajimehoshi/ebiten/v2#Image.DrawImage
+	for _, l := range tm.layers {
+		for i, t := range l {
+			op := &ebiten.DrawImageOptions{}
+			op.GeoM.Translate(float64((i%tm.mapWidth)*tm.tileSize), float64((i/tm.mapWidth)*tm.tileSize))
+
+			sx := (t % tileXCount) * tileSize
+			sy := (t / tileXCount) * tileSize
+			tm.surface.DrawImage(tm.tilesImage.SubImage(image.Rect(sx, sy, sx+tileSize, sy+tileSize)).(*ebiten.Image), op)
+		}
+	}
+
+    //ebitenutil.DebugPrint(screen, fmt.Sprintf("TPS: %0.2f", ebiten.ActualTPS()))
+}
+
+func NewTilemap(layers [][]int, mapWidth int) Tilemap {
+    tilemap := Tilemap{
+        tileSize: 16,
+        mapWidth: 15,
+    }
+
+    tilemap.layers = layers
+
+    tilemap.surface = ebiten.NewImage(mapWidth*tilemap.tileSize, len(layers[0])/mapWidth*tilemap.tileSize)
+
+    var err error
+	tilemap.tilesImage, _, err = ebitenutil.NewImageFromFile("Assets/Terrain/Terrain (16x16).png")
+
+	if err != nil {
+		log.Fatal(err)
+	}
+
+    tilemap.CalculateCollisions()
+
+    return tilemap
+}
+
+func (tm * Tilemap) CalculateCollisions() {
+    for i, t := range tm.layers[1] {
+        if t != 0 {
+            x := i%tm.mapWidth * tm.tileSize
+            y := i/tm.mapWidth * tm.tileSize
+
+            w, h := tm.tileSize, tm.tileSize
+            rect := image.Rect(x, y, x+w, y+h)
+            tm.collisions = append(tm.collisions, rect)
+            
+        }
+    }
+}
+
+func (t * Tilemap) Collide(x, y, width, height int) bool {
+    r1 :=  image.Rect(
+        x,
+        y,
+        x+width,
+        y+height,
+    )
+
+    for _, r2 := range t.collisions {
+        if ! ( r2.Min.X > r1.Max.X || r2.Max.X < r1.Min.X || r2.Min.Y > r1.Max.Y || r2.Max.Y < r1.Min.Y) {
+            return true
+
+        }
+    }
+    return false
+    
+}
+
+
+func (t * Tilemap) CollideObject(object *GameObject) bool {
+    width := object.image.Bounds().Dx()
+    height := object.image.Bounds().Dy()
+    x := int(object.x*float32(t.tileSize))
+    y := int(object.y*float32(t.tileSize))
+    return t.Collide(x, y, width, height)
+}
+
-- 
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