Mercurial > games > semicongine

changeset 1133:a52e924e5666

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add: function to generate circle-mesh data (not mesh object)
author sam <sam@basx.dev>
date Sun, 02 Jun 2024 16:21:52 +0700
parents 7f2c477ae1f4
children 055eb17ce31e
files semicongine/mesh.nim
diffstat 1 files changed, 10 insertions(+), 0 deletions(-) [+]
line wrap: on
line diff
--- a/semicongine/mesh.nim	Thu May 23 02:26:37 2024 +0700
+++ b/semicongine/mesh.nim	Sun Jun 02 16:21:52 2024 +0700
@@ -489,6 +489,16 @@
   result[].initVertexAttribute("color", @[colorVec, colorVec, colorVec])
   `material=`(result[], material)
 
+proc CircleMesh*(nSegments: int): (seq[Vec3f], seq[array[3, uint16]]) =
+  let
+    rX = 0.5
+    rY = 0.5
+    step = (2'f32 * PI) / float32(nSegments)
+  result[0] = @[newVec3f(0, 0), newVec3f(rX, 0)]
+  for i in 1 .. nSegments:
+    result[0].add newVec3f(cos(float32(i) * step) * rX, sin(float32(i) * step) * rY)
+    result[1].add [uint16(0), uint16(i), uint16(i + 1)]
+
 proc circle*(width = 1'f32, height = 1'f32, nSegments = 12, color = "ffffffff", material = EMPTY_MATERIAL.initMaterialData()): Mesh =
   assert nSegments >= 3
   result = Mesh(