fix bug with certain indices & vertices being overwritten when ensuri…

…ng buffer size inside Mesh & IndexedMesh
littlektframework · Dec 7, 2024 · a6e3dce · a6e3dce
1 parent 43f9010
commit a6e3dce
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Showing 2 changed files with 14 additions and 6 deletions.
diff --git a/core/src/commonMain/kotlin/com/littlekt/graphics/util/IndexedMeshGeometry.kt b/core/src/commonMain/kotlin/com/littlekt/graphics/util/IndexedMeshGeometry.kt
@@ -22,6 +22,7 @@ open class IndexedMeshGeometry(layout: VertexBufferLayout, size: Int = INITIAL_S
 
     /** The number of indices added to the [indices] buffer. */
     var numIndices: Int = 0
+        private set
 
     /** If the geometry has changed since last update. */
     override val dirty: Boolean
@@ -145,10 +146,13 @@ open class IndexedMeshGeometry(layout: VertexBufferLayout, size: Int = INITIAL_S
     }
 
     private fun increaseIndices(newSize: Int) {
+        logger.debug { "Increasing indices buffer size to $newSize" }
+        val oldPosition = indices.position
+        indices.position = 0
         val newData = ShortBuffer(newSize)
         newData.put(indices)
         indices = newData
-        indices.position = 0
+        indices.position = oldPosition
     }
 
     /** The type of shape indices buffer are used for. */

diff --git a/core/src/commonMain/kotlin/com/littlekt/graphics/util/MeshGeometry.kt b/core/src/commonMain/kotlin/com/littlekt/graphics/util/MeshGeometry.kt
@@ -3,6 +3,7 @@ package com.littlekt.graphics.util
 import com.littlekt.file.FloatBuffer
 import com.littlekt.graphics.VertexBufferLayout
 import com.littlekt.log.Logger
+import kotlin.jvm.JvmStatic
 import kotlin.math.max
 import kotlin.math.min
 import kotlin.math.round
@@ -68,7 +69,7 @@ open class MeshGeometry(val layout: VertexBufferLayout, size: Int = INITIAL_SIZE
         newVertices: FloatArray,
         srcOffset: Int = 0,
         dstOffset: Int = 0,
-        count: Int = newVertices.size - srcOffset
+        count: Int = newVertices.size - srcOffset,
     ) {
         ensureVertices(count / vertexSize)
         vertices.put(data = newVertices, dstOffset = dstOffset, srcOffset = srcOffset, len = count)
@@ -85,6 +86,7 @@ open class MeshGeometry(val layout: VertexBufferLayout, size: Int = INITIAL_SIZE
      * account the [vertexSize].
      */
     fun skip(totalVertices: Int) {
+        ensureVertices(totalVertices)
         vertices.position += totalVertices * vertexSize
         numVertices += totalVertices
     }
@@ -106,7 +108,7 @@ open class MeshGeometry(val layout: VertexBufferLayout, size: Int = INITIAL_SIZE
             increaseVertices(
                 max(
                     round(vertices.capacity * GROW_FACTOR).toInt(),
-                    (numVertices + required) * vertexSize
+                    (numVertices + required) * vertexSize,
                 )
             )
             return true
@@ -115,16 +117,18 @@ open class MeshGeometry(val layout: VertexBufferLayout, size: Int = INITIAL_SIZE
     }
 
     private fun increaseVertices(newSize: Int) {
+        logger.debug { "Increasing vertices buffer size to $newSize" }
+        val oldPos = vertices.position
         val newData = FloatBuffer(newSize)
+        vertices.position = 0
         newData.put(vertices)
         vertices = newData
-        vertices.position = 0
-        logger.debug { "Increasing vertices buffer size to $newSize" }
+        vertices.position = oldPos
     }
 
     companion object {
         private const val INITIAL_SIZE = 1000
         private const val GROW_FACTOR = 2f
-        private val logger = Logger<MeshGeometry>()
+        @JvmStatic protected val logger = Logger<MeshGeometry>()
     }
 }