simplify gg; remove forced OpenGL dependency; graph builder /w hot code reloading

compiler/parser.v

@@ -68,6 +68,7 @@ mut:
 	can_chash bool
 	attr string 
 	v_script bool // "V bash", import all os functions into global space 
+	var_decl_name string 	// To allow declaring the variable so that it can be used in the struct initialization 
 }
 
 const (
@@ -1173,6 +1174,7 @@ fn (p mut Parser) var_decl() {
 	}
 	// println('var decl tok=${p.strtok()} ismut=$is_mut')
 	name := p.check_name()
+	p.var_decl_name = name 
 	// Don't allow declaring a variable with the same name. Even in a child scope
 	// (shadowing is not allowed)
 	if !p.builtin_pkg && p.cur_fn.known_var(name) {
@@ -1186,6 +1188,7 @@ fn (p mut Parser) var_decl() {
 	// Generate expression to tmp because we need its type first
 	// [TYP .name =] bool_expression()
 	pos := p.cgen.add_placeholder()
+
 	mut typ := p.bool_expression()
 	// Option check ? or {
 	or_else := p.tok == .key_orelse 
@@ -1228,6 +1231,7 @@ fn (p mut Parser) var_decl() {
 		}
 		p.cgen.set_placeholder(pos, nt_gen)
 	}
+	p.var_decl_name = '' 
 }
 
 fn (p mut Parser) bool_expression() string {
@@ -1362,7 +1366,14 @@ fn (p mut Parser) name_expr() string {
 		name = p.prepend_pkg(name)
 	}
 	// Variable
-	v := p.cur_fn.find_var(name)
+	mut v := p.cur_fn.find_var(name)
+	// A hack to allow `newvar := Foo{ field: newvar }`  
+	// Declare the variable so that it can be used in the initialization 
+	if name == 'main__' + p.var_decl_name {
+		v.name = p.var_decl_name
+		v.typ = 'voidptr' 
+		v.is_mut = true 
+	} 
 	if v.name.len != 0 {
 		if ptr {
 			p.gen('& /*vvar*/ ')

examples/hot_code_reloading/graph.v

@@ -1,8 +1,8 @@
 module main
 
 import gx
-import gl
 import gg
+import time 
 import glfw 
 	
 const (
@@ -12,36 +12,30 @@ const (
 )
 
 struct Context {
-	mut:
 	gg *gg.GG
 }
 
 fn main() {
 	glfw.init()
-	mut ctx := &Context{gg: 0}
-	window := glfw.create_window(glfw.WinCfg{
-		title: 'graph builder'
-		width: 1000
-		height: 1000
-		ptr: ctx
-	})
-	window.make_context_current()
-	gg.init()
-	ctx.gg = gg.new_context(gg.Cfg {
-		 width: 1000
-		 height: 1000
-		 use_ortho: true 
-	})
+	ctx:= &Context{ 
+		gg: gg.new_context(gg.Cfg {
+			width: WIDTH 
+			height: HEIGHT 
+			use_ortho: true 
+			create_window: true 
+			window_title: 'graph builder' 
+			window_user_ptr: ctx 
+		})
+	} 
 	for { 
-		gl.clear()
-		gl.clear_color(255, 255, 255, 255)
+		gg.clear(gx.White) 
 		ctx.draw()
-		window.swap_buffers()
-		glfw.wait_events()
+		ctx.gg.render() 
 	}
 }
 
-fn (ctx mut Context) draw() {
+[live] 
+fn (ctx & Context) draw() {
 	// x axis
 	ctx.gg.draw_line(0, HEIGHT / 2, WIDTH, HEIGHT / 2)
 	// y axis
@@ -50,9 +44,11 @@ fn (ctx mut Context) draw() {
 	mut prev_y := f64(0)
 	center := f64(WIDTH / 2)
 	for x := f64(- 10); x <= f64(10); x += 0.01 {
-		y := x * x * f64(SCALE)
-		// gx.draw_line_c(center + prev_x, center+prev_y, center + int(x*float(10)), center+y, gx.BLACK)
-		ctx.gg.draw_rect(int(center) + int(x * f64(SCALE)), int(center - y), 1, 1, gx.Black)
+		//y := (x * x - 2) * f64(SCALE)
+		y := (1.0 / x) * f64(SCALE)
+		//ctx.gg.draw_line(int(center + prev_x), int(center+prev_y), 
+			//int(center + x*f64(10)), int(center+y))
+		ctx.gg.draw_rect(int(center) + int(x * f64(SCALE)), int(center - y), 2, 1, gx.Black)
 		// gx.draw_rect_f(center + (x * f64(SCALE)), center - y, 1, 1, gx.BLACK)
 		prev_x = x
 		prev_y = y

examples/tetris/tetris.v

@@ -104,41 +104,33 @@ struct Game {
 
 fn main() {
 	glfw.init()
-	mut game := &Game{gg: 0} // TODO
-	game.parse_tetros()
+	mut game := &Game{
+		gg: gg.new_context(gg.Cfg {
+			width: WinWidth
+			height: WinHeight
+			use_ortho: true // This is needed for 2D drawing
+			create_window: true
+			window_title: 'V Tetris'
+			window_user_ptr: game 
+		})
+	} 
 	game.init_game()
-	mut window := glfw.create_window(glfw.WinCfg {
-		width: WinWidth
-		height: WinHeight
-		title: 'V Tetris'
-		ptr: game // glfw user pointer
-	})
-	window.make_context_current()
-	window.onkeydown(key_down)
-	gg.init()
-	game.gg = gg.new_context(gg.Cfg {
-		width: WinWidth
-		height: WinHeight
-		use_ortho: true // This is needed for 2D drawing
-	})
+	game.gg.window.onkeydown(key_down)
 	go game.run() // Run the game loop in a new thread
-	gl.clear() // For some reason this is necessary to avoid an intial flickering
-	gl.clear_color(255, 255, 255, 255)
+	gg.clear(gx.White) 
 	for {
-		gl.clear()
-		gl.clear_color(255, 255, 255, 255)
+		gg.clear(gx.White) 
 		game.draw_scene()
-		window.swap_buffers()
-		glfw.wait_events()
-		if window.should_close() {
-			window.destroy()
-			glfw.terminate()
-			exit(0)
+		game.gg.render() 
+		if game.gg.window.should_close() {
+			game.gg.window.destroy()
+			return 
 		}
 	}
 }
 
 fn (g mut Game) init_game() {
+	g.parse_tetros()
 	rand.seed(time.now().uni)
 	g.generate_tetro()
 	g.field = []array_int // TODO: g.field = [][]int

vlib/gg/gg.v

@@ -9,6 +9,7 @@ import glm
 import gl
 import gx
 import os
+import glfw 
 
 struct Vec2 {
 	x int
@@ -36,6 +37,7 @@ pub fn vec2(x, y int) Vec2 {
 }
 
 pub fn init() {
+	glfw.init()
 	println(gl.TEXT_VERT)
 	gl.init_glad()
 }
@@ -49,7 +51,11 @@ struct Cfg {
 	height    int
 	use_ortho bool 
 	retina    bool
+	 
 	font_size int
+	create_window bool 
+	window_user_ptr voidptr 
+	window_title string 
 }
 
 struct GG {
@@ -64,12 +70,25 @@ struct GG {
 	line_vbo  u32
 	VBO       u32
 	scale     int // retina = 2 , normal = 1
+pub mut: 
+	window *glfw.Window 
+	render_fn fn() 
 }
 
+
 // fn new_context(width, height int, use_ortho bool, font_size int) *GG {
 pub fn new_context(cfg Cfg) *GG {
-	// println('new context orhto=$cfg.use_ortho')
-	// # glScissor(0,0,300,300);
+	mut window := &glfw.Window{!} 
+	if cfg.create_window {
+		window = glfw.create_window(glfw.WinCfg{
+			title: cfg.window_title 
+			width: cfg.width 
+			height: cfg.height 
+			ptr: cfg.window_user_ptr 
+		})
+		window.make_context_current()
+		init() 
+	} 
 	shader := gl.new_shader('simple')
 	shader.use()
 	if cfg.use_ortho { 
@@ -122,20 +141,43 @@ pub fn new_context(cfg Cfg) *GG {
 	//gl.enable_vertex_attrib_array(0)
 	//gl.vertex_attrib_pointer(0, 4, GL_FLOAT, false, 4, 0)
 	todo_remove_me(cfg, scale) 
-	mut ctx := &GG {
+	return &GG {
 		shader: shader 
 		width: cfg.width 
 		height: cfg.height 
 		VAO: vao 
 		VBO: vbo 
+		window: window 
+	 
 		// /line_vao: gl.gen_vertex_array()
 		// /line_vbo: gl.gen_buffer()
 		//text_ctx: new_context_text(cfg, scale),
 		scale: scale
 		// use_ortho: use_ortho
 	}
+
 	// ctx.init_rect_vao()
-	return ctx
+	//return ctx
+}
+
+/* 
+pub fn (gg &GG) render_loop() bool {
+	for !gg.window.show_close() { 
+		gg.render_fn() 
+		gg.window.swap_buffers()
+		glfw.wait_events()
+	} 
+} 
+*/ 
+
+pub fn clear(color gx.Color) { 
+	gl.clear()
+	gl.clear_color(255, 255, 255, 255)
+} 
+
+pub fn (gg &GG) render() { 
+	gg.window.swap_buffers()
+	glfw.wait_events()
 } 
 
 pub fn (ctx &GG) draw_triangle(x1, y1, x2, y2, x3, y3 f32, c gx.Color) {