From 44bf8c5d7ec70ae666977d7d72cc5ed4e8df2558 Mon Sep 17 00:00:00 2001
From: Arjun Nair <arjunair@gmail.com>
Date: Sun, 22 Oct 2023 22:08:38 +0530
Subject: [PATCH] Refactored code for dpi calculation so that default just
 works. Fixed clippy complaint.

---
 examples/basic.rs    |  6 +++---
 examples/demo_lib.rs |  4 ++--
 src/lib.rs           | 19 +++++++++++++------
 src/painter.rs       |  5 +++--
 4 files changed, 21 insertions(+), 13 deletions(-)

diff --git a/examples/basic.rs b/examples/basic.rs
index 10fa1b7..fa7df6a 100644
--- a/examples/basic.rs
+++ b/examples/basic.rs
@@ -1,7 +1,7 @@
 use egui::Checkbox;
+use egui_backend::egui::FullOutput;
 use egui_backend::sdl2::video::GLProfile;
 use egui_backend::{egui, gl, sdl2};
-use egui_backend::egui::FullOutput;
 use egui_backend::{sdl2::event::Event, DpiScaling, ShaderVersion};
 use std::time::Instant;
 // Alias the backend to something less mouthful
@@ -40,7 +40,7 @@ fn main() {
     // On linux use GLES SL 100+, like so:
     // let shader_ver = ShaderVersion::Adaptive;
     let (mut painter, mut egui_state) =
-        egui_backend::with_sdl2(&window, shader_ver, DpiScaling::Custom(2.0));
+        egui_backend::with_sdl2(&window, shader_ver, DpiScaling::Default);
     let egui_ctx = egui::Context::default();
     let mut event_pump = sdl_context.event_pump().unwrap();
 
@@ -65,7 +65,7 @@ fn main() {
                 .gl_set_swap_interval(SwapInterval::Immediate)
                 .unwrap()
         }
-        
+
         unsafe {
             // Clear the screen to green
             gl::ClearColor(0.3, 0.6, 0.3, 1.0);
diff --git a/examples/demo_lib.rs b/examples/demo_lib.rs
index 55b5dd3..1772910 100644
--- a/examples/demo_lib.rs
+++ b/examples/demo_lib.rs
@@ -56,7 +56,7 @@ fn main() {
 
     // Init egui stuff
     let (mut painter, mut egui_state) =
-        egui_backend::with_sdl2(&window, ShaderVersion::Default, DpiScaling::Custom(1.25));
+        egui_backend::with_sdl2(&window, ShaderVersion::Default, DpiScaling::Default);
     let mut demo_windows = egui_demo_lib::DemoWindows::default();
     let egui_ctx = egui::Context::default();
     let mut event_pump = sdl_context.event_pump().unwrap();
@@ -81,7 +81,7 @@ fn main() {
         });
 
         demo_windows.ui(&egui_ctx);
-        
+
         let FullOutput {
             platform_output,
             repaint_after,
diff --git a/src/lib.rs b/src/lib.rs
index efe9277..483866a 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -88,14 +88,21 @@ pub fn with_sdl2(
     shader_ver: ShaderVersion,
     scale: DpiScaling,
 ) -> (Painter, EguiStateHandler) {
-    let display_dpi = window
-        .subsystem()
-        .display_dpi(0)
-        .unwrap_or((96.0, 96.0, 96.0));
+    let standard_dpi = 96.0;
+    let display_dpi =
+        window
+            .subsystem()
+            .display_dpi(0)
+            .unwrap_or((standard_dpi, standard_dpi, standard_dpi));
+    let dpi_scale = standard_dpi / display_dpi.0;
+    let normalized_scale = 1.0 / dpi_scale;
+    let default_scale = dpi_scale * normalized_scale;
+    println!("Display DPI detected: {:?}", display_dpi);
     let scale = match scale {
-        DpiScaling::Default => 96.0 / display_dpi.0,
-        DpiScaling::Custom(custom) => (96.0 / display_dpi.0) * custom,
+        DpiScaling::Default => default_scale,
+        DpiScaling::Custom(custom) => default_scale * custom,
     };
+    println!("Scaling display to {}", scale);
     let painter = painter::Painter::new(window, scale, shader_ver);
     EguiStateHandler::new(painter)
 }
diff --git a/src/painter.rs b/src/painter.rs
index 84651f5..103c27f 100644
--- a/src/painter.rs
+++ b/src/painter.rs
@@ -514,8 +514,9 @@ impl Painter {
             {
                 match primitive {
                     Primitive::Mesh(mesh) => {
-                        if let Some(Texture { gl_id, .. }) = self.textures.get(&mesh.texture_id) {
-                            if let Some(texture_gl_id) = gl_id {
+                        if let Some(Texture {gl_id: Some(texture_gl_id),  .. }) = self.textures.get(&mesh.texture_id) {
+                            //if let Some(texture_gl_id) = gl_id 
+                            {
                                 gl::BindTexture(gl::TEXTURE_2D, *texture_gl_id);
 
                                 let clip_min_x = pixels_per_point * clip_rect.min.x;