--- a/tests/test_vulkan_wrapper.nim	Sat Aug 19 01:10:42 2023 +0700
+++ b/tests/test_vulkan_wrapper.nim	Sat Aug 19 22:24:06 2023 +0700
@@ -3,14 +3,16 @@
 import semicongine
 
 
-let sampler = Sampler(
+let
+  sampler = Sampler(
     magnification: VK_FILTER_NEAREST,
     minification: VK_FILTER_NEAREST,
     wrapModeS: VK_SAMPLER_ADDRESS_MODE_REPEAT,
     wrapModeT: VK_SAMPLER_ADDRESS_MODE_REPEAT,
   )
-let (R, W) = ([255'u8, 0'u8, 0'u8, 255'u8], [255'u8, 255'u8, 255'u8, 255'u8])
-let mat = Material(
+  (R, W) = ([255'u8, 0'u8, 0'u8, 255'u8], [255'u8, 255'u8, 255'u8, 255'u8])
+  mat = Material(
+    name: "mat",
     materialType: "my_material",
     textures: {
       "my_little_texture": Texture(image: Image(width: 5, height: 5, imagedata: @[
@@ -22,6 +24,26 @@
       ]), sampler: sampler)
     }.toTable
   )
+  mat2 = Material(
+    name: "mat2",
+    materialType: "my_material",
+    textures: {
+      "my_little_texture": Texture(image: Image(width: 5, height: 5, imagedata: @[
+      R, W, R, W, R,
+      W, R, W, R, W,
+      R, W, R, W, R,
+      W, R, W, R, W,
+      R, W, R, W, R,
+      ]), sampler: sampler)
+    }.toTable
+  )
+  mat3 = Material(
+    name: "mat3",
+    materialType: "my_special_material",
+    constants: {
+      "colors": toGPUValue(newVec4f(0.5, 0.5, 0))
+    }.toTable
+  )
 
 proc scene_different_mesh_types(): Entity =
   result = newEntity("root", [],
@@ -39,31 +61,35 @@
       positions=[newVec3f(0.0, 0.5), newVec3f(0.5, -0.5), newVec3f(-0.5, -0.5)],
       colors=[newVec4f(1.0, 0.0, 0.0, 1), newVec4f(0.0, 1.0, 0.0, 1), newVec4f(0.0, 0.0, 1.0, 1)],
       indices=[[0'u16, 2'u16, 1'u16]],
-      material=mat,
+      material=mat2,
     ))}),
     newEntity("triangle2b", {"mesh": Component(newMesh(
       positions=[newVec3f(0.0, 0.4), newVec3f(0.4, -0.4), newVec3f(-0.4, -0.4)],
       colors=[newVec4f(1.0, 0.0, 0.0, 1), newVec4f(0.0, 1.0, 0.0, 1), newVec4f(0.0, 0.0, 1.0, 1)],
       indices=[[0'u16, 2'u16, 1'u16]],
-      material=mat,
+      material=mat2,
     ))}),
     newEntity("triangle3a", {"mesh": Component(newMesh(
       positions=[newVec3f(0.4, 0.5), newVec3f(0.9, -0.3), newVec3f(0.0, -0.3)],
       colors=[newVec4f(1.0, 1.0, 0.0, 1), newVec4f(1.0, 1.0, 0.0, 1), newVec4f(1.0, 1.0, 0.0, 1)],
       indices=[[0'u32, 2'u32, 1'u32]],
       autoResize=false,
-      material=mat,
+      material=mat2,
     ))}),
     newEntity("triangle3b", {"mesh": Component(newMesh(
       positions=[newVec3f(0.4, 0.5), newVec3f(0.9, -0.3), newVec3f(0.0, -0.3)],
       colors=[newVec4f(1.0, 1.0, 0.0, 1), newVec4f(1.0, 1.0, 0.0, 1), newVec4f(1.0, 1.0, 0.0, 1)],
       indices=[[0'u32, 2'u32, 1'u32]],
       autoResize=false,
-      material=mat,
+      material=mat2,
     ))}),
   )
   for mesh in allComponentsOfType[Mesh](result):
     mesh.setInstanceData("translate", @[newVec3f()])
+  result[0]["mesh", Mesh()].updateInstanceData("translate", @[newVec3f(-0.6, -0.6)])
+  result[1]["mesh", Mesh()].updateInstanceData("translate", @[newVec3f(-0.6, 0.6)])
+  result[2]["mesh", Mesh()].updateInstanceData("translate", @[newVec3f(0.6, -0.6)])
+  result[3]["mesh", Mesh()].updateInstanceData("translate", @[newVec3f(0.6, 0.6)])
 
 proc scene_simple(): Entity =
   var mymesh1 = newMesh(
@@ -90,17 +116,17 @@
     instanceCount=2,
     material=mat,
   )
-  mymesh1.setInstanceData("translate", @[newVec3f(0.3, 0.0)])
-  mymesh2.setInstanceData("translate", @[newVec3f(0.0, 0.3)])
-  mymesh3.setInstanceData("translate", @[newVec3f(-0.3, 0.0)])
-  mymesh4.setInstanceData("translate", @[newVec3f(0.0, -0.3), newVec3f(0.0, 0.5)])
+  mymesh1.setInstanceData("translate", @[newVec3f( 0.4,  0.4)])
+  mymesh2.setInstanceData("translate", @[newVec3f( 0.4, -0.4)])
+  mymesh3.setInstanceData("translate", @[newVec3f(-0.4, -0.4)])
+  mymesh4.setInstanceData("translate", @[newVec3f(-0.4,  0.4), newVec3f(0.0, 0.0)])
   result = newEntity("root", [], newEntity("triangle", {"mesh1": Component(mymesh4), "mesh2": Component(mymesh3), "mesh3": Component(mymesh2), "mesh4": Component(mymesh1)}))
 
 proc scene_primitives(): Entity =
   var r = rect(color="ff0000")
   var t = tri(color="0000ff")
   var c = circle(color="00ff00")
-  t.material = mat
+  r.material = mat
   t.material = mat
   c.material = mat
 
@@ -110,11 +136,20 @@
   result = newEntity("root", {"mesh1": Component(t), "mesh2": Component(r), "mesh3": Component(c)})
 
 proc scene_flag(): Entity =
-  var r = rect(color="ff0000")
+  var r = rect(color="ffffff")
   r.material = mat
-  r.updateMeshData("color", @[newVec4f(0, 0), newVec4f(1, 0), newVec4f(1, 1), newVec4f(0, 1)])
   result = newEntity("root", {"mesh": Component(r)})
 
+proc scene_multi_material(): Entity =
+  var
+    r1 = rect(color="ffffff")
+    r2 = rect(color="000000")
+  r1.material = mat
+  r2.material = mat3
+  r1.setInstanceData("translate", @[newVec3f(-0.5)])
+  r2.setInstanceData("translate", @[newVec3f(+0.5)])
+  result = newEntity("root", {"mesh1": Component(r1), "mesh2": Component(r2)})
+
 proc main() =
   var engine = initEngine("Test")
 
@@ -124,23 +159,32 @@
       inputs=[
         attr[Vec3f]("position", memoryPerformanceHint=PreferFastRead),
         attr[Vec4f]("color", memoryPerformanceHint=PreferFastWrite),
-        attr[Vec3f]("translate", perInstance=true)
+        attr[Vec3f]("translate", perInstance=true),
+        attr[uint16]("materialIndex", perInstance=true),
       ],
-      intermediates=[attr[Vec4f]("outcolor")],
+      intermediates=[
+        attr[Vec4f]("outcolor"),
+        attr[uint16]("materialIndexOut", noInterpolation=true),
+      ],
       outputs=[attr[Vec4f]("color")],
       uniforms=[attr[float32]("time")],
-      samplers=[attr[Sampler2DType]("my_little_texture")],
-      vertexCode="""gl_Position = vec4(position + translate, 1.0); outcolor = color;""",
-      fragmentCode="color = texture(my_little_texture, outcolor.xy) * 0.5 + outcolor * 0.5;",
+      samplers=[
+        attr[Sampler2DType]("my_little_texture", arrayCount=2)
+      ],
+      vertexCode="""gl_Position = vec4(position + translate, 1.0); outcolor = color; materialIndexOut = materialIndex;""",
+      fragmentCode="color = texture(my_little_texture[materialIndexOut], outcolor.xy) * 0.5 + outcolor * 0.5;",
     )
-  engine.setRenderer({"my_material": shaderConfiguration}.toTable)
+  engine.initRenderer({
+    "my_material": shaderConfiguration,
+    "my_special_material": shaderConfiguration,
+  }.toTable)
 
   # INIT SCENES
   var scenes = [
-    newScene("simple", scene_simple(), transformAttribute="", materialIndexAttribute=""),
-    newScene("different mesh types", scene_different_mesh_types(), transformAttribute="", materialIndexAttribute=""),
-    newScene("primitives", scene_primitives(), transformAttribute="", materialIndexAttribute=""),
-    newScene("flag", scene_flag(), transformAttribute="", materialIndexAttribute=""),
+    newScene("simple", scene_simple(), transformAttribute=""),
+    newScene("different mesh types", scene_different_mesh_types(), transformAttribute=""),
+    newScene("primitives", scene_primitives(), transformAttribute=""),
+    newScene("flag", scene_multi_material(), transformAttribute=""),
   ]
 
   for scene in scenes.mitems: