Fix problem with tiles near viewport edge sometimes not being drawn w…

[americanjeff]

…hen tilemap container is rotated (e.g. camera angle change)

[soywiz]

@americanjeff thanks for the PR! In which cases does this PR fixes the issue? Is it a small rotation? A full 180º rotation, or other cases?

[americanjeff]

I only tested manually with a little demo I wrote but it seems to happen at a variety of angles https://youtube.com/shorts/3aVCVrIKlLE

Here's a little demo I wrote to test it

import com.soywiz.korge.*
import com.soywiz.korge.input.onScroll
import com.soywiz.korge.view.*
import com.soywiz.korge.view.camera.cameraContainer
import com.soywiz.korge.view.tiles.TileSet
import com.soywiz.korge.view.tiles.tileMap
import com.soywiz.korim.bitmap.Bitmap32
import com.soywiz.korim.color.*
import com.soywiz.korma.geom.*
import com.soywiz.korma.geom.Point.Companion.Zero
import kotlin.random.Random
import kotlin.math.*

suspend fun main() = Korge(width = 1024, height = 1024, bgcolor = Colors["#2b2b2b"]) {
	val tileSize = 200
	val tileSet = makeSimpleTileSet(tileSize)
	val mapSize = 100
	val donutMap = makeDonutMap(mapSize, tileSet)

	val cameraContainer = cameraContainer(width, height) {
		tileMap(donutMap, tileSet).centerOn(this)
	}
	cameraContainer.cameraY = -9000.0
	val statusOverlay = text("")

	var zoom = 0.0
	onScroll {
		println("onscroll: ${it.scrollDeltaYPixels}")
		zoom -= (it.scrollDeltaYPixels / 240)
		cameraContainer.cameraZoom = 2.0.pow(zoom)
	}

	var wasDown = false
	val downVals = object {
		var mouse: Point = Point()
		var camAngle: Angle = 0.degrees
		var camPos: Point = Point()
	}

	addUpdater {
		val mouseButtons = input.mouseButtons
		val isDown = (mouseButtons and 5) != 0
		if (isDown) {
			if (!wasDown) {
				wasDown = true
				downVals.mouse.copyFrom(input.mouse)
				downVals.camAngle = cameraContainer.cameraAngle
				downVals.camPos = Point(cameraContainer.cameraX, cameraContainer.cameraY)
			} else {
				val rightMouse = (mouseButtons and 4) != 0
				if (rightMouse) {
					val downAngle = Zero.angleTo(downVals.mouse)
					val mouseAngle = Zero.angleTo(input.mouse)
					val newAngle = downVals.camAngle - (downAngle - mouseAngle)
					val dy = downVals.mouse.y - input.mouse.y
					cameraContainer.cameraAngle = newAngle //downVals.camAngle - dy.degrees
				} else { // leftMouse
					val newCamPos =
						cameraContainer.content.globalToLocal(downVals.mouse) - cameraContainer.content.globalToLocal(input.mouse) + downVals.camPos
					cameraContainer.cameraX = newCamPos.x
					cameraContainer.cameraY = newCamPos.y
				}
			}
		}
		statusOverlay.text =  "zoom: $zoom\nangle: ${cameraContainer.cameraAngle}\npos: ${cameraContainer.cameraX}, ${cameraContainer.cameraY}"
		wasDown = isDown
	}
}

private fun makeDonutMap(
	mapWidth: Int,
	tileSet: TileSet
): Bitmap32 {
	val rand = Random(3)
	val mapValues2 = Bitmap32(mapWidth, mapWidth)
	val center = Point(mapWidth / 2, mapWidth / 2)
	for (x in 0 until mapWidth) for (y in 0 until mapWidth) {
		val p = Point(x, y)
		val dist = (p - center).length
		val onDisc = dist < mapWidth / 2
		val tooClose = dist < (mapWidth / 2) * 0.7
		mapValues2.intData[x * mapWidth + y] =
			if (onDisc && !tooClose) 1 + rand.nextInt(tileSet.texturesMap.size - 1) else 0
	}
	return mapValues2
}

private fun makeSimpleTileSet(tileWidth: Int): TileSet {
	val tileBitmaps =
		listOf(Colors.TRANSPARENT_BLACK, Colors.GREEN, Colors.ORANGE, Colors.GREENYELLOW, Colors.YELLOW).map { c ->
			Bitmap32(tileWidth, tileWidth).also {
				it.fill(c)
				for (i in (tileWidth / 5) until (tileWidth * 4 / 5)) {
					it[i, tileWidth / 2] = Colors.TRANSPARENT_BLACK
					it[tileWidth / 2, i] = Colors.TRANSPARENT_BLACK
				}
			}
		}
	return TileSet.fromBitmaps(tileWidth, tileWidth, tileBitmaps)
}

[soywiz]

Awesome. Thank you very much!

I have added your sample here: aab6102
It is possible to run it locally with ./gradlew :korge-sandbox:runJvm (and uncommenting the line in the main.kt in the case another sample is loaded)