From f28500d963d6546feda522d7748a0462a568ba28 Mon Sep 17 00:00:00 2001
From: James Barnett <noreply@jamesbarnett.xyz>
Date: Mon, 28 Dec 2020 15:49:23 +0000
Subject: Refactor components

---
 src/main/kotlin/Raycaster.kt | 42 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 42 insertions(+)
 create mode 100644 src/main/kotlin/Raycaster.kt

(limited to 'src/main/kotlin/Raycaster.kt')

diff --git a/src/main/kotlin/Raycaster.kt b/src/main/kotlin/Raycaster.kt
new file mode 100644
index 0000000..d3fa694
--- /dev/null
+++ b/src/main/kotlin/Raycaster.kt
@@ -0,0 +1,42 @@
+import kotlin.math.pow
+
+class Raycaster(private val stepPrecision: Int = 32) {
+
+  fun raycast(raycastContext: RaycastContext) {
+    val (renderer, camera, map, _) = raycastContext
+
+    val viewportWidth = renderer.viewportWidth
+    val viewportHeight = renderer.viewportHeight
+    val viewportHeightHalf = viewportHeight / 2
+
+    var raySweepAngle = camera.rotation - camera.halfFov
+
+    for (rayIndex in 0 until viewportWidth) {
+
+      var rayX = camera.xPos
+      var rayY = camera.yPos
+
+      do {
+        rayX += kotlin.math.cos(toRadians(raySweepAngle)) / stepPrecision
+        rayY += kotlin.math.sin(toRadians(raySweepAngle)) / stepPrecision
+        // TODO bounds checking
+        val wallHit = map.data[kotlin.math.floor(rayY).toInt()][kotlin.math.floor(rayX).toInt()] > 0
+      } while (!wallHit)
+
+      val distanceToWall = kotlin.math.sqrt((camera.xPos - rayX).pow(2) + (camera.yPos - rayY).pow(2))
+      val wallHeight = kotlin.math.floor(viewportHeightHalf / distanceToWall).toInt()
+
+      // Sky
+      renderer.drawLine(rayIndex, 0, rayIndex, viewportHeightHalf - wallHeight, "cyan")
+      // Wall
+      renderer.drawLine(rayIndex, viewportHeightHalf - wallHeight, rayIndex, viewportHeightHalf + wallHeight, "red")
+      // Floor
+      renderer.drawLine(rayIndex, viewportHeightHalf + wallHeight, rayIndex, viewportHeight, "green")
+
+      raySweepAngle += (camera.fov / viewportWidth.toDouble())
+    }
+  }
+
+
+
+}
\ No newline at end of file
-- 
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