import std/strformat
import semicongine

const
  MeshMaterial* = MaterialType(
    name: "colored single texture material",
    vertexAttributes: {
      "position": Vec3F32,
      "texcoord_0": Vec2F32,
    }.toTable,
    attributes: {"baseTexture": TextureType, "color": Vec4F32}.toTable
  )

proc main() =
  var scenes = [
    Scene(name: "Donut", meshes: loadMeshes("donut.glb", MeshMaterial)[0].toSeq),
  ]

  var engine = initEngine("Test meshes")
  const
    shaderConfiguration = createShaderConfiguration(
      name = "default shader",
      inputs = [
        attr[Vec3f]("position", memoryPerformanceHint = PreferFastRead),
        attr[uint16](MATERIALINDEX_ATTRIBUTE, memoryPerformanceHint = PreferFastRead, perInstance = true),
        attr[Vec2f]("texcoord_0", memoryPerformanceHint = PreferFastRead),
        attr[Mat4]("transform", memoryPerformanceHint = PreferFastWrite, perInstance = true),
      ],
      intermediates = [
        attr[Vec4f]("vertexColor"),
        attr[Vec2f]("colorTexCoord"),
        attr[uint16]("materialIndexOut", noInterpolation = true)
      ],
      outputs = [attr[Vec4f]("color")],
      uniforms = [
        attr[Mat4]("projection"),
        attr[Mat4]("view"),
        attr[Vec4f]("color", arrayCount = 4),
      ],
      samplers = [attr[Texture]("baseTexture", arrayCount = 4)],
      vertexCode = &"""
  gl_Position =  vec4(position, 1.0) * (transform * (Uniforms.view * Uniforms.projection));
  vertexColor = Uniforms.color[{MATERIALINDEX_ATTRIBUTE}];
  colorTexCoord = texcoord_0;
  materialIndexOut = {MATERIALINDEX_ATTRIBUTE};
  """,
      fragmentCode = "color = texture(baseTexture[materialIndexOut], colorTexCoord) * vertexColor;"
    )
  engine.initRenderer({MeshMaterial: shaderConfiguration})

  for scene in scenes.mitems:
    scene.addShaderGlobal("projection", Unit4F32)
    scene.addShaderGlobal("view", Unit4F32)
    engine.loadScene(scene)

  var
    size = 1'f32
    elevation = 0'f32
    azimut = 0'f32
    currentScene = 0

  while engine.updateInputs() and not keyIsDown(Escape):
    if keyWasPressed(`1`):
      currentScene = 0
    elif keyWasPressed(`2`):
      currentScene = 1
    elif keyWasPressed(`3`):
      currentScene = 2
    elif keyWasPressed(`4`):
      currentScene = 3
    elif keyWasPressed(`5`):
      currentScene = 4
    elif keyWasPressed(`6`):
      currentScene = 5

    if keyWasPressed(NumberRowExtra3):
      size = 0.3'f32
      elevation = 0'f32
      azimut = 0'f32

    let ratio = engine.getWindow().size[0] / engine.getWindow().size[1]
    size *= 1'f32 + mouseWheel() * 0.05
    azimut += mouseMove().x / 180'f32
    elevation -= mouseMove().y / 180'f32
    scenes[currentScene].setShaderGlobal("projection", perspective(PI / 2, ratio, -0.5, 1))
    scenes[currentScene].setShaderGlobal(
      "view",
       scale(size, size, size) * rotate(elevation, newVec3f(1, 0, 0)) * rotate(azimut, Yf32)
    )
    engine.renderScene(scenes[currentScene])
  engine.destroy()

when isMainModule:
  main()