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dwursteisenclaude
dwursteisen
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claude
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Add text Lua library for custom font rendering
Introduce a new `text` Lua lib that allows game developers to configure custom fonts via `_tiny.json` and render text with them. Supports font selection by index/name, multiline text, pixel width measurement, and falls back to the boot font when no custom font is selected. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
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‎tiny-engine/src/commonMain/kotlin/com/github/minigdx/tiny/engine/FontDescriptor.kt‎

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@@ -0,0 +1,102 @@
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package com.github.minigdx.tiny.engine
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import kotlin.math.max
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data class CharResolution(
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val sourceX: Int,
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val sourceY: Int,
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val charWidth: Int,
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val charHeight: Int,
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)
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data class FontBank(
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val name: String,
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val charWidth: Int,
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val charHeight: Int,
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val x: Int,
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val y: Int,
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val charMap: Map<Int, Pair<Int, Int>>,
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)
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data class FontDescriptor(
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val name: String,
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val spritesheet: String,
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val spaceWidth: Int,
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val lineHeight: Int,
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val banks: List<FontBank>,
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) {
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fun resolve(codepoint: Int): CharResolution? {
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for (bank in banks) {
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val coord = bank.charMap[codepoint]
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if (coord != null) {
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return CharResolution(
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sourceX = bank.x + coord.first * bank.charWidth,
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sourceY = bank.y + coord.second * bank.charHeight,
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charWidth = bank.charWidth,
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charHeight = bank.charHeight,
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)
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}
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}
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return null
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}
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companion object {
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fun fromConfig(config: GameConfigFont): FontDescriptor {
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var maxHeight = 0
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val banks = config.banks.map { bankConfig ->
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val bank = FontBank(
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name = bankConfig.name,
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charWidth = bankConfig.width,
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charHeight = bankConfig.height,
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x = bankConfig.x,
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y = bankConfig.y,
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charMap = buildCharMap(bankConfig.characters),
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)
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maxHeight = max(maxHeight, bankConfig.height)
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bank
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}
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val defaultSpaceWidth = config.banks.firstOrNull()?.let { it.width / 2 } ?: 4
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return FontDescriptor(
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name = config.name,
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spritesheet = config.spritesheet,
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spaceWidth = config.spaceWidth ?: defaultSpaceWidth,
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lineHeight = maxHeight,
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banks = banks,
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)
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}
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}
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}
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/**
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* KMP-compatible codepoint iteration with surrogate pair handling.
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* Skips variation selectors (U+FE0E, U+FE0F).
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*/
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inline fun String.forEachCodepoint(action: (codepoint: Int) -> Unit) {
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var i = 0
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while (i < length) {
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val c = this[i]
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val codepoint = if (c.isHighSurrogate() && i + 1 < length && this[i + 1].isLowSurrogate()) {
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val low = this[i + 1]
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i += 2
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((c.code - 0xD800) shl 10) + (low.code - 0xDC00) + 0x10000
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} else {
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i++
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c.code
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}
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if (codepoint != 0xFE0E && codepoint != 0xFE0F) {
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action(codepoint)
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}
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}
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}
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fun buildCharMap(characters: List<String>): Map<Int, Pair<Int, Int>> {
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val map = mutableMapOf<Int, Pair<Int, Int>>()
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characters.forEachIndexed { row, line ->
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var col = 0
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line.forEachCodepoint { codepoint ->
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map[codepoint] = col to row
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col++
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}
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}
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return map
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}

‎tiny-engine/src/commonMain/kotlin/com/github/minigdx/tiny/engine/GameConfig.kt‎

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@@ -25,6 +25,24 @@ sealed class GameConfig {
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@Serializable
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data class GameConfigSize(val width: Int, val height: Int)
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@Serializable
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data class GameConfigFontBank(
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val name: String,
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val width: Int,
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val height: Int,
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val characters: List<String>,
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val x: Int = 0,
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val y: Int = 0,
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)
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@Serializable
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data class GameConfigFont(
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val name: String,
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val spritesheet: String,
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val spaceWidth: Int? = null,
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val banks: List<GameConfigFontBank>,
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)
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@SerialName("V1")
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@Serializable
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data class GameConfigV1(
@@ -45,6 +63,7 @@ data class GameConfigV1(
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* When set, this script will be used as the first script to run.
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*/
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val bootScript: String? = null,
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val fonts: List<GameConfigFont> = emptyList(),
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) : GameConfig() {
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override fun toGameOptions(): GameOptions =
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GameOptions(
@@ -59,5 +78,8 @@ data class GameConfigV1(
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sound = sound,
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hideMouseCursor = hideMouseCursor,
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bootScript = bootScript,
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fonts = fonts.map { font ->
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FontDescriptor.fromConfig(font)
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},
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)
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}

‎tiny-engine/src/commonMain/kotlin/com/github/minigdx/tiny/engine/GameOptions.kt‎

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@@ -21,6 +21,7 @@ data class GameOptions(
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val hideMouseCursor: Boolean = false,
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val bootScript: String? = null,
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val icon: String? = null,
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val fonts: List<FontDescriptor> = emptyList(),
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) : MouseProject {
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init {
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require(width > 0) { "The width needs to be a positive number." }

‎tiny-engine/src/commonMain/kotlin/com/github/minigdx/tiny/engine/GameResourceAccess.kt‎

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@@ -56,4 +56,14 @@ interface GameResourceAccess {
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fun findSound(name: String): Sound?
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fun findGameScript(name: String): GameScript?
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/**
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* Access a font spritesheet by its index.
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*/
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fun findFontSpritesheet(index: Int): SpriteSheet?
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/**
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* Find a font spritesheet by its name.
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*/
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fun findFontSpritesheet(name: String): SpriteSheet?
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}

‎tiny-engine/src/commonMain/kotlin/com/github/minigdx/tiny/engine/GameResourceProcessor.kt‎

Lines changed: 25 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -12,6 +12,7 @@ import com.github.minigdx.tiny.resources.ResourceType
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import com.github.minigdx.tiny.resources.ResourceType.BOOT_GAMESCRIPT
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import com.github.minigdx.tiny.resources.ResourceType.BOOT_SPRITESHEET
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import com.github.minigdx.tiny.resources.ResourceType.ENGINE_GAMESCRIPT
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import com.github.minigdx.tiny.resources.ResourceType.FONT_SPRITESHEET
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import com.github.minigdx.tiny.resources.ResourceType.GAME_GAMESCRIPT
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import com.github.minigdx.tiny.resources.ResourceType.GAME_LEVEL
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import com.github.minigdx.tiny.resources.ResourceType.GAME_SOUND
@@ -39,6 +40,7 @@ class GameResourceProcessor(
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private var spriteSheets: Array<SpriteSheet?>
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private val levels: Array<GameLevel?>
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private val sounds: Array<Sound?>
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private val fontSheets: Array<SpriteSheet?>
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override var bootSpritesheet: SpriteSheet? = null
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private set
@@ -88,6 +90,11 @@ class GameResourceProcessor(
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Sound(0, 0, "default-sound", SoundData.DEFAULT_EMPTY)
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}
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val fontSpritesheets = gameOptions.fonts.mapIndexed { index, font ->
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resourceFactory.fontSpritesheet(index, font.spritesheet)
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}
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this.fontSheets = Array(fontSpritesheets.size) { null }
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val bootScriptFlow = if (gameOptions.bootScript != null) {
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resourceFactory.customBootScript(gameOptions.bootScript)
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} else {
@@ -99,7 +106,7 @@ class GameResourceProcessor(
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bootScriptFlow,
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resourceFactory.enginescript("_engine.lua"),
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resourceFactory.bootSpritesheet("_boot.png"),
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) + gameScripts + spriteSheets + gameLevels + listOfNotNull(sounds)
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) + gameScripts + spriteSheets + gameLevels + listOfNotNull(sounds) + fontSpritesheets
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toBeLoaded.addAll(
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setOf(bootScriptName, "_engine.lua", "_boot.png"),
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toBeLoaded.addAll(gameOptions.gameScripts)
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toBeLoaded.addAll(gameOptions.spriteSheets)
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gameOptions.sound?.let { toBeLoaded.add(it) }
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toBeLoaded.addAll(gameOptions.fonts.map { it.spritesheet })
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numberOfResources = resources.size
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logger.debug("GAME_ENGINE") { "Number of resources to load: $numberOfResources" }
@@ -167,6 +175,7 @@ class GameResourceProcessor(
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GAME_SPRITESHEET -> loadGameSpriteSheet(resource)
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GAME_LEVEL -> loadGameLevel(resource)
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GAME_SOUND -> loadGameSound(resource)
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FONT_SPRITESHEET -> loadFontSpriteSheet(resource)
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PRIMITIVE_SPRITESHEET -> Unit
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}
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}
@@ -190,6 +199,13 @@ class GameResourceProcessor(
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spritesheetToBind.addAll(gameLevel.tilesset.values)
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}
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private fun loadFontSpriteSheet(resource: GameResource) {
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val spriteSheet = resource as SpriteSheet
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spriteSheet.textureUnit = fontSheets[resource.index]?.textureUnit
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fontSheets[resource.index] = spriteSheet
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spritesheetToBind.add(spriteSheet)
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}
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private fun loadGameSpriteSheet(resource: GameResource) {
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val spriteSheet = resource as SpriteSheet
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// Copy the texture unit used by the current spritesheet
@@ -292,6 +308,14 @@ class GameResourceProcessor(
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return scripts.find { it?.name == name }
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}
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override fun findFontSpritesheet(index: Int): SpriteSheet? {
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return fontSheets.atIndex(index)
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}
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override fun findFontSpritesheet(name: String): SpriteSheet? {
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return fontSheets.find { it?.name == name }
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}
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fun status(): Map<ResourceType, Collection<GameResource>> {
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return gameResourceCollector.status()
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}

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