import myou_engine

# Create engine, scene, camera
let engine = newMyouEngine(1024, 768)
let scene = engine.newScene()
let cam = scene.newCamera() # this sets the active camera if there's none
scene.background_color = vec4(0.1, 0.1, 0.1, 1)

# Move the camera upwards (the default rotation looks down)
cam.position.z = 10

# Create a simple square mesh with UV
let quad = scene.newMesh("quad",
    common_attributes = {vertex, uv},
    vertex_array = @[
        # x,  y,  z,   U, V,
        -1f, -1,  0,   0, 0,
         1,  -1,  0,   1, 0,
        -1,   1,  0,   0, 1,
         1,   1,  0,   1, 1,
    ],
    index_array = @[0'u16, 1, 2, 2, 1, 3],
)

# Make the object wider with a 3:2 aspect ratio
quad.scale.x = 1.5

# This example texture is 1 pixel wide and 8 pixels high,
# to make a stripped flag
# NOTE: The colors are SRGB_u8, not RGB, but we're skipping output encoding
# in the shader for simplicity
let width = 1
let height = 8
let format = RGB_u8

# The texture goes from bottom to top
# (unless we invert the Y coordinate of the UV)
let pixels = @[
    115, 41,  130,
    36,  64,  142,
    0,   128, 38,
    255, 237, 0,
    255, 140, 0,
    228, 3,   3,
    120, 79,  23,
    0,   0,   0,
]

# Create the texture, use Nearest filter
# to have a sharp bands instead of a gradient
doAssert width * height * 3 == pixels.len
let texture = engine.newTexture("test",
    width = width, height = height,
    format = format, filter = Nearest,
    pixels = newArrRef[uint8](pixels).to float32)

# Minimal example of a material with a UV and a texture uniform
quad.materials.add engine.newMaterial("shadeless texture",
    fragment = """
        uniform sampler2D tex;
        in vec2 uv;
        out vec4 glOutColor;
        void main(){
            glOutColor = texture(tex, uv);
        }""",
    varyings = @[Varying(vtype: Uv, varname: "uv")],
    textures = {
        "tex": texture,
    }.toOrderedTable,
)

scene.enable_render()
engine.run()