[orx-obj-loader] Add support for wireframes and non-planar and concave faces

2024-07-15 22:26:18 +02:00
parent bc72991827
commit 8ceaf00f7a
10 changed files with 601 additions and 130 deletions
--- a/orx-obj-loader/src/main/kotlin/MeshDataExtensions.kt
+++ b/orx-obj-loader/src/main/kotlin/MeshDataExtensions.kt
@@ -0,0 +1,43 @@
+package org.openrndr.extra.objloader
+
+import org.openrndr.draw.VertexBuffer
+import org.openrndr.draw.vertexBuffer
+import org.openrndr.draw.vertexFormat
+import org.openrndr.math.Vector2
+
+private val objVertexFormat = vertexFormat {
+    position(3)
+    normal(3)
+    textureCoordinate(2)
+}
+
+fun MeshData.toVertexBuffer() : VertexBuffer {
+    val objects = triangulate().flattenPolygons()
+    val triangleCount = objects.values.sumOf { it.size }
+    val vertexBuffer = vertexBuffer(objVertexFormat, triangleCount * 3)
+
+    vertexBuffer.put {
+        objects.entries.forEach {
+            it.value.forEach {
+                for (i in it.positions.indices) {
+                    write(it.positions[i])
+                    if (it.normals.isNotEmpty()) {
+                        write(it.normals[i])
+                    } else {
+                        val d0 = it.positions[2] - it.positions[0]
+                        val d1 = it.positions[1] - it.positions[0]
+                        write(d0.normalized.cross(d1.normalized).normalized)
+                    }
+                    if (it.textureCoords.isNotEmpty()) {
+                        write(it.textureCoords[i])
+                    } else {
+                        write(Vector2.ZERO)
+                    }
+                }
+            }
+        }
+    }
+
+    vertexBuffer.shadow.destroy()
+    return vertexBuffer
+}