From 80edb6d4fe8c4af5b01176bcd956df37a24438a8 Mon Sep 17 00:00:00 2001
From: Tor Andersson <tor.andersson@artifex.com>
Date: Fri, 13 Apr 2018 12:50:01 +0200
Subject: gl: Increase font size on high resolution displays.

Also increase the max resolution in the zoom list.
---
 platform/gl/gl-ui.c | 25 +++++++++++++++++++++----
 1 file changed, 21 insertions(+), 4 deletions(-)

(limited to 'platform/gl/gl-ui.c')

diff --git a/platform/gl/gl-ui.c b/platform/gl/gl-ui.c
index 606afed9..a91723b8 100644
--- a/platform/gl/gl-ui.c
+++ b/platform/gl/gl-ui.c
@@ -369,6 +369,8 @@ static void on_warning(const char *fmt, va_list ap)
 
 void ui_init(int w, int h, const char *title)
 {
+	float ui_scale;
+
 	glutSetOption(GLUT_ACTION_ON_WINDOW_CLOSE, GLUT_ACTION_GLUTMAINLOOP_RETURNS);
 
 	glutInitErrorFunc(on_error);
@@ -396,10 +398,25 @@ void ui_init(int w, int h, const char *title)
 
 	glGetIntegerv(GL_MAX_TEXTURE_SIZE, &max_texture_size);
 
-	ui.fontsize = DEFAULT_UI_FONTSIZE;
-	ui.baseline = DEFAULT_UI_BASELINE;
-	ui.lineheight = DEFAULT_UI_LINEHEIGHT;
-	ui.gridsize = DEFAULT_UI_GRIDSIZE;
+	ui_scale = 1;
+	{
+		int wmm = glutGet(GLUT_SCREEN_WIDTH_MM);
+		int wpx = glutGet(GLUT_SCREEN_WIDTH);
+		int hmm = glutGet(GLUT_SCREEN_HEIGHT_MM);
+		int hpx = glutGet(GLUT_SCREEN_HEIGHT);
+		if (wmm > 0 && hmm > 0)
+		{
+			float ppi = ((wpx * 254) / wmm + (hpx * 254) / hmm) / 20;
+			if (ppi >= 144) ui_scale = 1.5f;
+			if (ppi >= 192) ui_scale = 2.0f;
+			if (ppi >= 288) ui_scale = 3.0f;
+		}
+	}
+
+	ui.fontsize = DEFAULT_UI_FONTSIZE * ui_scale;
+	ui.baseline = DEFAULT_UI_BASELINE * ui_scale;
+	ui.lineheight = DEFAULT_UI_LINEHEIGHT * ui_scale;
+	ui.gridsize = DEFAULT_UI_GRIDSIZE * ui_scale;
 
 	ui_init_fonts(ui.fontsize);
 }
-- 
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