Initial implementation

12 files changed, 531 insertions, 0 deletions

diff --git a/.gitignore b/.gitignore
index a1c2a23..df925b1 100644
--- a/.gitignore
+++ b/.gitignore
@@ -21,3 +21,8 @@
 
 # virtual machine crash logs, see http://www.java.com/en/download/help/error_hotspot.xml
 hs_err_pid*
+
+
+.gradle
+.idea
+build
\ No newline at end of file
diff --git a/build.gradle.kts b/build.gradle.kts
new file mode 100644
index 0000000..38847fa
--- /dev/null
+++ b/build.gradle.kts
@@ -0,0 +1,22 @@
+plugins {
+  kotlin("js") version "1.4.21"
+}
+
+group = "io.jamesbarnett"
+version = "1.0-SNAPSHOT"
+
+repositories {
+  jcenter()
+  mavenCentral()
+}
+
+kotlin {
+  js(LEGACY) {
+    browser {
+      testTask {
+        enabled = false
+      }
+      binaries.executable()
+    }
+  }
+}
\ No newline at end of file
diff --git a/gradle.properties b/gradle.properties
new file mode 100644
index 0000000..7fc6f1f
--- /dev/null
+++ b/gradle.properties
@@ -0,0 +1 @@
+kotlin.code.style=official
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
new file mode 100644
index 0000000..12d38de
--- /dev/null
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -0,0 +1,5 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-6.6.1-bin.zip
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists
diff --git a/gradlew b/gradlew
new file mode 100755
index 0000000..4f906e0
--- /dev/null
+++ b/gradlew
@@ -0,0 +1,185 @@
+#!/usr/bin/env sh
+
+#
+# Copyright 2015 the original author or authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+##############################################################################
+##
+##  Gradle start up script for UN*X
+##
+##############################################################################
+
+# Attempt to set APP_HOME
+# Resolve links: $0 may be a link
+PRG="$0"
+# Need this for relative symlinks.
+while [ -h "$PRG" ] ; do
+    ls=`ls -ld "$PRG"`
+    link=`expr "$ls" : '.*-> \(.*\)$'`
+    if expr "$link" : '/.*' > /dev/null; then
+        PRG="$link"
+    else
+        PRG=`dirname "$PRG"`"/$link"
+    fi
+done
+SAVED="`pwd`"
+cd "`dirname \"$PRG\"`/" >/dev/null
+APP_HOME="`pwd -P`"
+cd "$SAVED" >/dev/null
+
+APP_NAME="Gradle"
+APP_BASE_NAME=`basename "$0"`
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD="maximum"
+
+warn () {
+    echo "$*"
+}
+
+die () {
+    echo
+    echo "$*"
+    echo
+    exit 1
+}
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "`uname`" in
+  CYGWIN* )
+    cygwin=true
+    ;;
+  Darwin* )
+    darwin=true
+    ;;
+  MINGW* )
+    msys=true
+    ;;
+  NONSTOP* )
+    nonstop=true
+    ;;
+esac
+
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
+
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+        # IBM's JDK on AIX uses strange locations for the executables
+        JAVACMD="$JAVA_HOME/jre/sh/java"
+    else
+        JAVACMD="$JAVA_HOME/bin/java"
+    fi
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD="java"
+    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+fi
+
+# Increase the maximum file descriptors if we can.
+if [ "$cygwin" = "false" -a "$darwin" = "false" -a "$nonstop" = "false" ] ; then
+    MAX_FD_LIMIT=`ulimit -H -n`
+    if [ $? -eq 0 ] ; then
+        if [ "$MAX_FD" = "maximum" -o "$MAX_FD" = "max" ] ; then
+            MAX_FD="$MAX_FD_LIMIT"
+        fi
+        ulimit -n $MAX_FD
+        if [ $? -ne 0 ] ; then
+            warn "Could not set maximum file descriptor limit: $MAX_FD"
+        fi
+    else
+        warn "Could not query maximum file descriptor limit: $MAX_FD_LIMIT"
+    fi
+fi
+
+# For Darwin, add options to specify how the application appears in the dock
+if $darwin; then
+    GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\""
+fi
+
+# For Cygwin or MSYS, switch paths to Windows format before running java
+if [ "$cygwin" = "true" -o "$msys" = "true" ] ; then
+    APP_HOME=`cygpath --path --mixed "$APP_HOME"`
+    CLASSPATH=`cygpath --path --mixed "$CLASSPATH"`
+
+    JAVACMD=`cygpath --unix "$JAVACMD"`
+
+    # We build the pattern for arguments to be converted via cygpath
+    ROOTDIRSRAW=`find -L / -maxdepth 1 -mindepth 1 -type d 2>/dev/null`
+    SEP=""
+    for dir in $ROOTDIRSRAW ; do
+        ROOTDIRS="$ROOTDIRS$SEP$dir"
+        SEP="|"
+    done
+    OURCYGPATTERN="(^($ROOTDIRS))"
+    # Add a user-defined pattern to the cygpath arguments
+    if [ "$GRADLE_CYGPATTERN" != "" ] ; then
+        OURCYGPATTERN="$OURCYGPATTERN|($GRADLE_CYGPATTERN)"
+    fi
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    i=0
+    for arg in "$@" ; do
+        CHECK=`echo "$arg"|egrep -c "$OURCYGPATTERN" -`
+        CHECK2=`echo "$arg"|egrep -c "^-"`                                 ### Determine if an option
+
+        if [ $CHECK -ne 0 ] && [ $CHECK2 -eq 0 ] ; then                    ### Added a condition
+            eval `echo args$i`=`cygpath --path --ignore --mixed "$arg"`
+        else
+            eval `echo args$i`="\"$arg\""
+        fi
+        i=`expr $i + 1`
+    done
+    case $i in
+        0) set -- ;;
+        1) set -- "$args0" ;;
+        2) set -- "$args0" "$args1" ;;
+        3) set -- "$args0" "$args1" "$args2" ;;
+        4) set -- "$args0" "$args1" "$args2" "$args3" ;;
+        5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
+        6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
+        7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
+        8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
+        9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
+    esac
+fi
+
+# Escape application args
+save () {
+    for i do printf %s\\n "$i" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/" ; done
+    echo " "
+}
+APP_ARGS=`save "$@"`
+
+# Collect all arguments for the java command, following the shell quoting and substitution rules
+eval set -- $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS "\"-Dorg.gradle.appname=$APP_BASE_NAME\"" -classpath "\"$CLASSPATH\"" org.gradle.wrapper.GradleWrapperMain "$APP_ARGS"
+
+exec "$JAVACMD" "$@"
diff --git a/gradlew.bat b/gradlew.bat
new file mode 100644
index 0000000..107acd3
--- /dev/null
+++ b/gradlew.bat
@@ -0,0 +1,89 @@
+@rem
+@rem Copyright 2015 the original author or authors.
+@rem
+@rem Licensed under the Apache License, Version 2.0 (the "License");
+@rem you may not use this file except in compliance with the License.
+@rem You may obtain a copy of the License at
+@rem
+@rem      https://www.apache.org/licenses/LICENSE-2.0
+@rem
+@rem Unless required by applicable law or agreed to in writing, software
+@rem distributed under the License is distributed on an "AS IS" BASIS,
+@rem WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+@rem See the License for the specific language governing permissions and
+@rem limitations under the License.
+@rem
+
+@if "%DEBUG%" == "" @echo off
+@rem ##########################################################################
+@rem
+@rem  Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+set DIRNAME=%~dp0
+if "%DIRNAME%" == "" set DIRNAME=.
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Resolve any "." and ".." in APP_HOME to make it shorter.
+for %%i in ("%APP_HOME%") do set APP_HOME=%%~fi
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS="-Xmx64m" "-Xms64m"
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if "%ERRORLEVEL%" == "0" goto execute
+
+echo.
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto execute
+
+echo.
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:execute
+@rem Setup the command line
+
+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
+
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %*
+
+:end
+@rem End local scope for the variables with windows NT shell
+if "%ERRORLEVEL%"=="0" goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+if  not "" == "%GRADLE_EXIT_CONSOLE%" exit 1
+exit /b 1
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega
diff --git a/settings.gradle.kts b/settings.gradle.kts
new file mode 100644
index 0000000..3f40476
--- /dev/null
+++ b/settings.gradle.kts
@@ -0,0 +1 @@
+rootProject.name = "kotlin-raycaster"
diff --git a/src/main/kotlin/Camera.kt b/src/main/kotlin/Camera.kt
new file mode 100644
index 0000000..7d4bcfc
--- /dev/null
+++ b/src/main/kotlin/Camera.kt
@@ -0,0 +1,8 @@
+class Camera(
+  val fov: Int,
+  var xPos: Double,
+  var yPos: Double,
+  var rotation: Double
+) {
+  val halfFov = fov / 2
+}
\ No newline at end of file
diff --git a/src/main/kotlin/Minimap.kt b/src/main/kotlin/Minimap.kt
new file mode 100644
index 0000000..dc7cc91
--- /dev/null
+++ b/src/main/kotlin/Minimap.kt
@@ -0,0 +1,57 @@
+import kotlinx.browser.document
+import org.w3c.dom.CanvasRenderingContext2D
+import org.w3c.dom.HTMLCanvasElement
+
+class Minimap(private val map: List<List<Int>>) {
+
+  private val scale = 30
+  private val mapWidth = map[0].size
+  private val mapHeight = map.size
+
+  private val canvas = (document.createElement("canvas") as HTMLCanvasElement)
+    .apply {
+      width = mapWidth * scale
+      height = mapHeight * scale
+      id = "minimap"
+      style.width = "${width}px"
+      style.height = "${height}px"
+    }
+  private val context = canvas.getContext("2d") as CanvasRenderingContext2D
+
+  init {
+    document.body!!.appendChild(canvas)
+  }
+
+  private fun drawMap() {
+    for (y in 0 until mapHeight) {
+      for (x in 0 until mapWidth) {
+        val wall = map[y][x]
+        if (wall > 0) {
+          context.fillStyle = "#000000"
+          context.fillRect((x * scale).toDouble(), (y * scale).toDouble(), scale.toDouble(), scale.toDouble())
+        }
+      }
+    }
+  }
+
+  fun update(camera: Camera) {
+    context.clearRect(0.0, 0.0, (mapWidth * scale).toDouble(), (mapHeight * scale).toDouble())
+    drawMap()
+    context.fillStyle = "#FF0000"
+    context.fillRect(camera.xPos * scale, camera.yPos * scale, scale.toDouble(), scale.toDouble())
+
+    context.strokeStyle = "#00FF00"
+    context.lineWidth = 2.0
+    context.beginPath()
+    context.moveTo(camera.xPos * scale, camera.yPos * scale)
+
+    val cameraCos = kotlin.math.cos(toRadians(camera.rotation)) * 4
+    val cameraSin = kotlin.math.sin(toRadians(camera.rotation)) * 4
+
+    val dirX = camera.xPos + cameraCos
+    val dirY = camera.yPos + cameraSin
+
+    context.lineTo(dirX * scale, dirY * scale)
+    context.stroke()
+  }
+}
\ No newline at end of file
diff --git a/src/main/kotlin/Renderer.kt b/src/main/kotlin/Renderer.kt
new file mode 100644
index 0000000..b266e61
--- /dev/null
+++ b/src/main/kotlin/Renderer.kt
@@ -0,0 +1,31 @@
+import kotlinx.browser.document
+import org.w3c.dom.CanvasRenderingContext2D
+import org.w3c.dom.HTMLCanvasElement
+
+class Renderer(val w: Int, val h: Int) {
+
+  private val canvas = (document.createElement("canvas") as HTMLCanvasElement)
+    .apply {
+      width = w
+      height = h
+    }
+  private val context = canvas.getContext("2d") as CanvasRenderingContext2D
+
+  init {
+    document.body!!.appendChild(canvas)
+  }
+
+  fun drawLine(startX: Int, startY: Int, endX: Int, endY: Int, cssColour: String = "#FF0000") {
+    context.strokeStyle = cssColour
+    context.lineWidth = 4.0
+    context.beginPath()
+    context.moveTo(startX.toDouble(), startY.toDouble())
+    context.lineTo(endX.toDouble(), endY.toDouble())
+    context.stroke()
+  }
+
+  fun clear() {
+    context.clearRect(0.0, 0.0, w.toDouble(), h.toDouble())
+  }
+
+}
\ No newline at end of file
diff --git a/src/main/kotlin/raycaster.kt b/src/main/kotlin/raycaster.kt
new file mode 100644
index 0000000..5b717bc
--- /dev/null
+++ b/src/main/kotlin/raycaster.kt
@@ -0,0 +1,117 @@
+import kotlinx.browser.document
+import kotlin.math.pow
+
+private const val SCREEN_WIDTH = 640
+private const val SCREEN_HEIGHT = 480
+private const val MOVE_SPEED = 0.5
+private const val ROTATE_SPEED = 5
+
+private val map = listOf(
+  listOf(1,1,1,1,1,1,1,1,1,1),
+  listOf(1,0,0,0,0,0,0,0,0,1),
+  listOf(1,0,0,0,0,0,0,0,0,1),
+  listOf(1,0,0,1,1,0,1,0,0,1),
+  listOf(1,0,0,1,0,0,1,0,0,1),
+  listOf(1,0,0,1,0,0,1,0,0,1),
+  listOf(1,0,0,1,0,1,1,0,0,1),
+  listOf(1,0,0,0,0,0,0,0,0,1),
+  listOf(1,0,0,0,0,0,0,0,0,1),
+  listOf(1,1,1,1,1,1,1,1,1,1)
+)
+
+data class RaycastContext(
+  val renderer: Renderer,
+  val camera: Camera,
+  val minimap: Minimap
+)
+
+fun main() {
+  val renderer = Renderer(SCREEN_WIDTH, SCREEN_HEIGHT)
+  val camera = Camera(
+    fov = 60,
+    xPos = 2.0,
+    yPos = 2.0,
+    rotation = 90.0
+  )
+  val minimap = Minimap(map)
+
+  val context = RaycastContext(renderer, camera, minimap)
+
+  document.onkeydown = {
+    when (it.code) {
+      "KeyW" -> {
+        console.log("key w")
+        val cameraCos = kotlin.math.cos(toRadians(camera.rotation)) * MOVE_SPEED
+        val cameraSin = kotlin.math.sin(toRadians(camera.rotation)) * MOVE_SPEED
+        camera.xPos += cameraCos
+        camera.yPos += cameraSin
+      }
+      "KeyS" -> {
+        console.log("key s")
+        val cameraCos = kotlin.math.cos(toRadians(camera.rotation)) * MOVE_SPEED
+        val cameraSin = kotlin.math.sin(toRadians(camera.rotation)) * MOVE_SPEED
+        camera.xPos -= cameraCos
+        camera.yPos -= cameraSin
+      }
+      "KeyA" -> {
+        console.log("key a")
+        camera.rotation -= ROTATE_SPEED
+      }
+      "KeyD" -> {
+        console.log("key d")
+        camera.rotation += ROTATE_SPEED
+      }
+    }
+    paint(context)
+    console.log("camera x:${camera.xPos} y:${camera.yPos} r: ${camera.rotation}")
+  }
+
+  paint(context)
+}
+
+fun paint(raycastContext: RaycastContext) {
+  raycastContext.renderer.clear()
+  raycast(raycastContext)
+  raycastContext.minimap.update(raycastContext.camera)
+}
+
+fun raycast(raycastContext: RaycastContext) {
+  val incrementAngle : Double = raycastContext.camera.fov / SCREEN_WIDTH.toDouble()
+  val rayCastPrecision = 32
+
+  var rayAngle = raycastContext.camera.rotation - raycastContext.camera.halfFov
+
+  for (rayIndex in 0 until SCREEN_WIDTH) {
+
+    var rayX = raycastContext.camera.xPos
+    var rayY = raycastContext.camera.yPos
+
+    val rayCos = kotlin.math.cos(toRadians(rayAngle)) / rayCastPrecision
+    val raySin = kotlin.math.sin(toRadians(rayAngle)) / rayCastPrecision
+
+    var isWall = false
+    while(!isWall) {
+      rayX += rayCos
+      rayY += raySin
+
+      // TODO bounds checking
+      val foo = map[kotlin.math.floor(rayY).toInt()][kotlin.math.floor(rayX).toInt()]
+      if (foo == 1) {
+        isWall = true
+      }
+    }
+
+    val distance = kotlin.math.sqrt((raycastContext.camera.xPos - rayX).pow(2) + (raycastContext.camera.yPos - rayY).pow(2))
+    val wallHeight = kotlin.math.floor((SCREEN_HEIGHT/2) / distance).toInt()
+
+    raycastContext.renderer.drawLine(rayIndex, 0, rayIndex, (SCREEN_HEIGHT/2)-wallHeight, "cyan")
+    raycastContext.renderer.drawLine(rayIndex, (SCREEN_HEIGHT/2)-wallHeight, rayIndex, (SCREEN_HEIGHT/2)+wallHeight, "red")
+    raycastContext.renderer.drawLine(rayIndex, (SCREEN_HEIGHT/2)+wallHeight, rayIndex, SCREEN_HEIGHT, "green")
+
+    rayAngle += incrementAngle
+  }
+}
+
+fun toRadians(degrees: Double): Double {
+  return degrees * kotlin.math.PI / 180
+}
diff --git a/src/main/resources/index.html b/src/main/resources/index.html
new file mode 100644
index 0000000..787422b
--- /dev/null
+++ b/src/main/resources/index.html
@@ -0,0 +1,10 @@
+<!DOCTYPE html>
+<html lang="en">
+  <head>
+    <meta charset="UTF-8">
+    <title>Kotlin Raycaster</title>
+  </head>
+  <body>
+    <script src="kotlin-raycaster.js"></script>
+  </body>
+</html>