js,gg: more work on porting gg to JS backend (#12903)

vlib/gg/gg.js.v

@@ -1,5 +1,6 @@
 module gg
 
+import gx
 import js.dom
 
 pub enum DOMEventType {
@@ -55,37 +56,6 @@ pub mut:
 	framebuffer_height int
 }
 
-pub struct Context {
-mut:
-	render_text   bool = true
-	image_cache   []Image
-	needs_refresh bool = true
-	ticks         int
-pub mut:
-	scale         f32 = 1.0
-	width         int
-	height        int
-	window        JS.Window
-	config        Config
-	user_data     voidptr
-	ui_mode       bool
-	frame         u64
-	mbtn_mask     byte
-	mouse_buttons MouseButtons
-	mouse_pos_x   int
-	mouse_pos_y   int
-	mouse_dx      int
-	mouse_dy      int
-	scroll_x      int
-	scroll_y      int
-	//
-	key_modifiers     Modifier // the current key modifiers
-	key_repeat        bool     // whether the pressed key was an autorepeated one
-	pressed_keys      [key_code_max]bool // an array representing all currently pressed keys
-	pressed_keys_edge [key_code_max]bool // true when the previous state of pressed_keys,
-	// *before* the current event was different
-}
-
 pub enum DOMMouseButton {
 	invalid = -1
 	left = 0
@@ -226,3 +196,152 @@ pub enum DOMKeyCode {
 	right_super = 347
 	menu = 348
 }
+
+pub struct Config {
+pub:
+	width         int
+	height        int
+	use_ortho     bool // unused, still here just for backwards compatibility
+	retina        bool
+	resizable     bool
+	user_data     voidptr
+	font_size     int
+	create_window bool
+	// window_user_ptr voidptr
+	window_title      string
+	borderless_window bool
+	always_on_top     bool
+	bg_color          gx.Color
+	init_fn           FNCb   = voidptr(0)
+	frame_fn          FNCb   = voidptr(0)
+	native_frame_fn   FNCb   = voidptr(0)
+	cleanup_fn        FNCb   = voidptr(0)
+	fail_fn           FNFail = voidptr(0)
+	//
+	event_fn FNEvent = voidptr(0)
+	quit_fn  FNEvent = voidptr(0)
+	//
+	keydown_fn FNKeyDown = voidptr(0)
+	keyup_fn   FNKeyUp   = voidptr(0)
+	char_fn    FNChar    = voidptr(0)
+	//
+	move_fn    FNMove    = voidptr(0)
+	click_fn   FNClick   = voidptr(0)
+	unclick_fn FNUnClick = voidptr(0)
+	leave_fn   FNEvent   = voidptr(0)
+	enter_fn   FNEvent   = voidptr(0)
+	resized_fn FNEvent   = voidptr(0)
+	scroll_fn  FNEvent   = voidptr(0)
+	// wait_events       bool // set this to true for UIs, to save power
+	fullscreen    bool
+	scale         f32 = 1.0
+	sample_count  int
+	swap_interval int = 1 // 1 = 60fps, 2 = 30fps etc. The preferred swap interval (ignored on some platforms)
+	// ved needs this
+	// init_text bool
+	font_path             string
+	custom_bold_font_path string
+	ui_mode               bool // refreshes only on events to save CPU usage
+	// font bytes for embedding
+	font_bytes_normal []byte
+	font_bytes_bold   []byte
+	font_bytes_mono   []byte
+	font_bytes_italic []byte
+	native_rendering  bool // Cocoa on macOS/iOS, GDI+ on Windows
+	// drag&drop
+	enable_dragndrop             bool // enable file dropping (drag'n'drop), default is false
+	max_dropped_files            int = 1 // max number of dropped files to process (default: 1)
+	max_dropped_file_path_length int = 2048 // max length in bytes of a dropped UTF-8 file path (default: 2048)
+	context                      JS.CanvasRenderingContext2D
+}
+
+pub struct Context {
+mut:
+	render_text   bool = true
+	image_cache   []Image
+	needs_refresh bool = true
+	ticks         int
+pub mut:
+	scale         f32 = 1.0
+	width         int
+	height        int
+	window        JS.Window    [noinit]
+	config        Config
+	user_data     voidptr
+	ui_mode       bool
+	frame         u64
+	mbtn_mask     byte
+	mouse_buttons MouseButtons
+	mouse_pos_x   int
+	mouse_pos_y   int
+	mouse_dx      int
+	mouse_dy      int
+	scroll_x      int
+	scroll_y      int
+	//
+	key_modifiers     Modifier // the current key modifiers
+	key_repeat        bool     // whether the pressed key was an autorepeated one
+	pressed_keys      [key_code_max]bool // an array representing all currently pressed keys
+	pressed_keys_edge [key_code_max]bool // true when the previous state of pressed_keys,
+	canvas            JS.CanvasRenderingContext2D [noinit]
+	// *before* the current event was different
+}
+
+pub fn new_context(cfg Config) &Context {
+	mut g := &Context{}
+	g.user_data = cfg.user_data
+	g.width = cfg.width
+	g.height = cfg.height
+	g.ui_mode = cfg.ui_mode
+	g.config = cfg
+	if isnil(cfg.user_data) {
+		g.user_data = g
+	}
+	g.window = dom.window()
+	g.canvas = cfg.context
+
+	return g
+}
+
+pub fn (mut ctx Context) run() {
+	gg_animation_frame_fn(mut ctx)
+}
+
+pub fn (mut ctx Context) begin() {
+	// ctx.canvas.beginPath()
+}
+
+pub fn (mut ctx Context) end() {
+	// ctx.canvas.closePath()
+}
+
+pub fn (mut ctx Context) draw_line(x1 f32, y1 f32, x2 f32, y2 f32, c gx.Color) {
+	ctx.canvas.beginPath()
+	ctx.canvas.strokeStyle = c.to_css_string().str
+	ctx.canvas.moveTo(x1, y1)
+	ctx.canvas.lineTo(x2, y2)
+	ctx.canvas.stroke()
+	ctx.canvas.closePath()
+}
+
+pub fn (mut ctx Context) draw_rect(x f32, y f32, w f32, h f32, c gx.Color) {
+	ctx.canvas.beginPath()
+	ctx.canvas.fillStyle = c.to_css_string().str
+	ctx.canvas.fillRect(x, y, w, h)
+	ctx.canvas.closePath()
+}
+
+fn gg_animation_frame_fn(mut g Context) {
+	g.frame++
+	g.canvas.clearRect(0, 0, g.config.width, g.config.height)
+	// todo(playXE): handle events
+	if !isnil(g.config.frame_fn) {
+		f := g.config.frame_fn
+		f(g.user_data)
+		g.needs_refresh = false
+	}
+
+	g.window.requestAnimationFrame(fn [mut g] (time JS.Number) {
+		gg_animation_frame_fn(mut g)
+	})
+}