From 2237968ec1992730635e595653e600ed0b251fe6 Mon Sep 17 00:00:00 2001
From: Delyan Angelov <delian66@gmail.com>
Date: Thu, 4 Jun 2020 21:09:46 +0300
Subject: [PATCH] gg: fix x11 scaling

---
 examples/tetris/tetris.v |  3 +--
 vlib/gg/gg.v             | 18 ++++++++++++------
 2 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/examples/tetris/tetris.v b/examples/tetris/tetris.v
index 702d55889a..f040835501 100644
--- a/examples/tetris/tetris.v
+++ b/examples/tetris/tetris.v
@@ -139,7 +139,7 @@ struct Game {
 
 const ( fpath = os.resource_abs_path('../assets/fonts/RobotoMono-Regular.ttf') )
 fn init_gui(mut game Game){
-	x := ft.new({ font_path: fpath, scale: 2 }) or {panic(err)}
+	x := ft.new({ font_path: fpath, scale: sapp.dpi_scale() }) or {panic(err)}
 	game.ft = x
 	game.font_loaded = true
 }
@@ -184,7 +184,6 @@ fn main() {
 		init_fn: init_gui
 		frame_fn: frame
 		event_fn: on_event
-		scale: 2
 		//wait_events: true
 	)
 	game.init_game()
diff --git a/vlib/gg/gg.v b/vlib/gg/gg.v
index c030b70bc9..cf815bba9b 100644
--- a/vlib/gg/gg.v
+++ b/vlib/gg/gg.v
@@ -29,7 +29,6 @@ pub:
 	window_title  string
 	borderless_window bool
 	always_on_top bool
-	scale         f32  = 1.0
 	bg_color      gx.Color
 	init_fn       FNvoidptr1 = voidptr(0)
 	frame_fn      FNvoidptr1 = voidptr(0)
@@ -42,8 +41,8 @@ pub:
 }
 
 pub struct Context {
-	scale      f32 = 1.0// retina = 2 , normal = 1
 pub mut:
+	scale      f32 = 1.0 // will get set to 2.0 for retina, will remain 1.0 for normal
 	width      int
 	height     int
 	clear_pass C.sg_pass_action
@@ -67,6 +66,16 @@ fn gg_init_sokol_window(user_data voidptr) {
 	gfx.setup(&desc)
 	sgl_desc := C.sgl_desc_t{}
 	sgl.setup(&sgl_desc)
+	g.scale = sapp.dpi_scale()
+	// NB: on older X11, `Xft.dpi` from ~/.Xresources, that sokol uses,
+	// may not be set which leads to sapp.dpi_scale reporting incorrectly 0.0
+	if g.scale < 0.1 {
+		g.scale = 1.0
+	}
+	is_high_dpi := sapp.high_dpi()
+	fb_w := sapp.width()
+	fb_h := sapp.height()
+	println('g.scale=$g.scale is_high_dpi=$is_high_dpi fb_w=$fb_w fb_h=$fb_h')
 	if g.config.init_fn != voidptr(0) {
 		g.config.init_fn( g.config.user_data )
 	}
@@ -111,7 +120,6 @@ pub fn new_context(cfg Config) &Context{
 		height: cfg.height
 		clear_pass: gfx.create_clear_pass( f32(cfg.bg_color.r) / 255.0, f32(cfg.bg_color.g) / 255.0,
 f32(cfg.bg_color.b) / 255.0, 1.0)
-		scale: cfg.scale //sapp.dpi_scale()// cfg.scale
 		config: cfg
 	}
 
@@ -127,11 +135,9 @@ f32(cfg.bg_color.b) / 255.0, 1.0)
 		html5_canvas_name: cfg.window_title.str
 		width: cfg.width
 		height: cfg.height
-		high_dpi: cfg.scale > 1
+		high_dpi: true
 		fullscreen: cfg.fullscreen
 	}
-	//b := sapp.high_dpi()
-	//println('scale=$g.scale high_dpi=$b')
 	if cfg.use_ortho {}
 	else {}
 	g.window = window