x.v

// Build this example with
// v -live bounce.v
module main

import gx
import gg
import time
import sokol.gfx

struct Game {
mut:
	gg       &gg.Context
	x        int
	y        int
	dy       int
	dx       int
	height   int
	width    int
	draw_fn  voidptr
    bground  gg.Image
}

const (
	window_width = 400
	window_height = 300
	width = 50
)

fn main() {
	mut game := &Game{
		gg: 0
		dx: 2
		dy: 2
		height: window_height
		width: window_width
		draw_fn: 0
	}
	game.gg = gg.new_context({
		width: window_width
		height: window_height
		font_size: 20
		use_ortho: true
		user_data: game
		window_title: 'Hot code reloading demo'
		create_window: true
		frame_fn: frame
		bg_color: gx.white
        init_fn: init_fn
	})
	// window.onkeydown(key_down)
	println('Starting the game loop...')
	go game.run()
	game.gg.run()
}


struct Mat32 { pub: data [6]f32 }

fn layout_desc_make_default() C.sg_layout_desc {
   mut layout := C.sg_layout_desc {}
   layout.attrs[0] = C.sg_vertex_attr_desc{
      format: .float2 // position
   }
   layout.attrs[1] = C.sg_vertex_attr_desc{
      format: .float2 // tex coords
   }
   layout.attrs[2] = C.sg_vertex_attr_desc{
      format: .ubyte4n // color
   }
   return layout
}

fn init_fn (mut game Game) {
    game.bground = gg.create_image2('/home/delian/.vmodules/ui/examples/logo.png')

    mut shader_desc := C.sg_shader_desc{ 
        label: &byte(0)
    }
    shader_desc.set_frag_image(0, 'MainTex')
    shader_desc.set_vert_src('
void main() {
   gl_FrontColor = gl_FrontMaterial.diffuse;
   gl_Position = ftransform(); 
}
    ')
    shader_desc.set_frag_src('
void main() {
    gl_FragColor = gl_Color; 
}
    ')
    shader := gfx.make_shader(&shader_desc)

    pipdesc := C.sg_pipeline_desc{
      layout: layout_desc_make_default()
      index_type: .uint16
      label: &byte(0)
      shader: shader
      blend: C.sg_blend_state {
          enabled: true
          src_factor_rgb: .src_alpha
          dst_factor_rgb: .one_minus_src_alpha
          src_factor_alpha: .one
          dst_factor_alpha: .one_minus_src_alpha
      }
    }
    pip := C.sg_make_pipeline(&pipdesc)
    C.sg_apply_pipeline(pip)

}

// Try uncommenting or changing the lines inside the live functions.
// Guess what will happen:
[live]
fn frame (mut game Game) {
	game.gg.begin()
    
	C.sgl_enable_texture()
	C.sgl_texture(game.bground.sokol_img)
    C.sgl_begin_quads()
    //
    awidth := 200  aheight := 200
    dx := 0    dy := 0     dw := 200  dh := 200
    sx := 0    sy := 0     sw := 200  sh := 200
    u0 := f32(sx) / f32(awidth)
    v0 := f32(sy) / f32(aheight)
    u1 := f32(sx + sw) / f32(awidth)
    v1 := f32(sy + sh) / f32(aheight)
    x0 := f32(dx)
    y0 := f32(dy)
    x1 := f32(dx + dw)
    y1 := f32(dy + dh)
    //
    C.sgl_v2f_t2f_c4f(x0, y0,   u0, v0,   1.0, 1.0, 1.0, 1.0)
    C.sgl_v2f_t2f_c4f(x1, y0,   u1, v0,   0.0, 0.0, 1.0, 0.5)
    C.sgl_v2f_t2f_c4f(x1, y1,   u1, v1,   0.0, 0.0, 1.0, 1.0)
    C.sgl_v2f_t2f_c4f(x0, y1,   u0, v1,   0.0, 1.0, 1.0, 1.0)
    C.sgl_end()
    C.sgl_disable_texture()

	game.gg.draw_rect(game.x, game.y, width, width, gx.blue)
	game.gg.draw_rect(window_width - width - game.x + 10, 200 - game.y + width, width, width, gx.rgb(228, 10, 55))
	game.gg.draw_rect(game.x - 25, 250 - game.y, width, width, gx.rgb(28, 240, 55))
	game.gg.end()
}

[live]
fn (mut game Game) update_model() {
	speed := 2
	game.x += speed * game.dx
	game.y += speed * game.dy
	if game.y >= game.height - width || game.y <= 0 {
		game.dy = -game.dy
	}
	if game.x >= game.width - width || game.x <= 0 {
		game.dx = -game.dx
	}
}

fn (mut game Game) run() {
	for {
		game.update_model()
		//glfw.post_empty_event() // Refresh
		time.sleep_ms(17) // 60fps
	}
}