import gg
import os.asset
import sokol.sgl

// If you have emscripten (see https://emscripten.org/docs/getting_started/index.html), you can compile this program to WASM, using:
// `v -os wasm32_emscripten -o examples/gg/rotating_textured_quad.html examples/gg/rotating_textured_quad.v`, and later check with:
// `emrun examples/gg/rotating_textured_quad.html` .
#flag wasm32_emscripten --embed-file @VEXEROOT/examples/assets/logo.png@/assets/logo.png
#flag wasm32_emscripten --embed-file @VEXEROOT/examples/assets/fonts/RobotoMono-Regular.ttf@/assets/RobotoMono-Regular.ttf

pub struct Window {
pub mut:
    ctx &gg.Context = unsafe { nil }
    img gg.Image
}

pub fn (mut window Window) init() {
    image_path := asset.get_path('../assets', 'logo.png')
    window.img = window.ctx.create_image(image_path) or { panic(err) }
}

pub fn (mut window Window) draw() {
    angle := f32(window.ctx.frame) / 64 // since window.ctx.frame is increased by 1 on every frame -> the angle will be increasing too
    window.ctx.begin()
    sgl.load_pipeline(window.ctx.pipeline.alpha)

    sgl.translate(250, 250, 0) // center of the screen
    sgl.rotate(angle, 0.0, 0.0, 1.0) // rotate around the Z axis pointing towards the camera

    sgl.enable_texture()
    sgl.texture(window.img.simg, window.img.ssmp)
    sgl.begin_quads()
    sgl.c4b(255, 255, 255, 255)
    sgl.v3f_t2f(200, 200, 0, 1.0, 1.0)
    sgl.v3f_t2f(200, -200, 0, 1.0, 0.0)
    sgl.v3f_t2f(-200, -200, 0, 0.0, 0.0)
    sgl.v3f_t2f(-200, 200, 0, 0.0, 1.0)
    sgl.end()
    sgl.disable_texture()
    window.ctx.end()
}

fn main() {
    mut window := &Window{}
    window.ctx = gg.new_context(
        window_title: 'Rotating V logo'
        bg_color:     gg.light_green
        width:        500
        height:       500
        user_data:    window
        init_fn:      window.init
        frame_fn:     window.draw
        font_path:    asset.get_path('../assets', 'RobotoMono-Regular.ttf')
    )
    window.ctx.run()
}