diff examples/alotof_triangles.nim @ 22:b45a5d338cd0

did: improve alotof_triangles example, remove glslang lib, use only binary, easier cross-compilation
author Sam <sam@basx.dev>
date Wed, 11 Jan 2023 00:43:17 +0700
parents 316923e9247c
children b1b05d4efb52
line wrap: on
line diff
--- a/examples/alotof_triangles.nim	Tue Jan 10 00:24:37 2023 +0700
+++ b/examples/alotof_triangles.nim	Wed Jan 11 00:43:17 2023 +0700
@@ -1,3 +1,4 @@
+import std/math
 import std/random
 
 import zamikongine/engine
@@ -13,13 +14,19 @@
     position11: VertexAttribute[Vec2[float32]]
     color22: VertexAttribute[Vec3[float32]]
 
+proc randomtransform(): Mat33[float32] =
+  let randomscale = scale2d(float32(rand(1.0) + 0.5), float32(rand(1.0) + 0.5))
+  let randomrotate = rotate2d(float32(rand(2 * PI)))
+  let randomtranslate = translate2d(float32(rand(1.6) - 0.8), float32(rand(1.6) - 0.8))
+  result = randomtranslate * randomrotate * randomscale
+
 when isMainModule:
   randomize()
   var myengine = igniteEngine()
   const baseTriangle = [
-    Vec3([-0.3'f32, -0.3'f32, 1'f32]),
-    Vec3([ 0.3'f32,  0.3'f32, 1'f32]),
-    Vec3([-0.3'f32,  0.3'f32, 1'f32]),
+    Vec3([-0.1'f32, -0.1'f32, 1'f32]),
+    Vec3([ 0.1'f32,  0.1'f32, 1'f32]),
+    Vec3([-0.1'f32,  0.1'f32, 1'f32]),
   ]
 
   var scene = new Thing
@@ -27,13 +34,13 @@
   for i in 1 .. 300:
     var randommesh = new Mesh[VertexDataA]
     # TODO: create randomized position11 from baseTriangle with random transformation matrix
-    var transform = (Mat33[float32]().randomized() * 2'f32) - 1'f32
+    let transform1 = randomtransform()
     randommesh.vertexData = VertexDataA(
       position11: VertexAttribute[Vec2[float32]](
         data: @[
-          Vec2[float32](transform * baseTriangle[0]),
-          Vec2[float32](transform * baseTriangle[1]),
-          Vec2[float32](transform * baseTriangle[2]),
+          Vec2[float32](transform1 * baseTriangle[0]),
+          Vec2[float32](transform1 * baseTriangle[1]),
+          Vec2[float32](transform1 * baseTriangle[2]),
         ]
       ),
       color22: VertexAttribute[Vec3[float32]](
@@ -45,13 +52,14 @@
       )
     )
 
+    let transform2 = randomtransform()
     var randomindexedmesh = new IndexedMesh[VertexDataA, uint16]
     randomindexedmesh.vertexData = VertexDataA(
       position11: VertexAttribute[Vec2[float32]](
         data: @[
-          Vec2[float32](transform * baseTriangle[0]),
-          Vec2[float32](transform * baseTriangle[1]),
-          Vec2[float32](transform * baseTriangle[2]),
+          Vec2[float32](transform2 * baseTriangle[0]),
+          Vec2[float32](transform2 * baseTriangle[1]),
+          Vec2[float32](transform2 * baseTriangle[2]),
         ]
       ),
       color22: VertexAttribute[Vec3[float32]](
@@ -62,7 +70,7 @@
         ]
       )
     )
-    randomindexedmesh.indices = @[[0'u16, 1'u16, 2'u16], [0'u16, 2'u16, 1'u16]]
+    randomindexedmesh.indices = @[[0'u16, 1'u16, 2'u16]]
     var childthing = new Thing
     childthing.parts.add randommesh
     childthing.parts.add randomindexedmesh