Fix botched mouse handling

CHANGELOG.md

@@ -0,0 +1,11 @@
+# Change Log
+
+## [v0.5.1] - 2018-08-25
+
+Started a change log!
+
+### Fixed
+
+ - Vertical mouse position was wrong, v0.5.0 changed coordinate systems from a window-like one
+   to a UV-like one (0, 0 is now the lower left) but the glutin basic input feature did not
+   respect this and reported old style mouse positions

examples/game_of_life.rs

@@ -4,6 +4,7 @@ use mini_gl_fb::{Config, BufferFormat};
 use mini_gl_fb::glutin::{MouseButton, VirtualKeyCode};
 
 use std::time::SystemTime;
+use std::cmp;
 
 const WIDTH: usize = 200;
 const HEIGHT: usize = 200;
@@ -45,7 +46,9 @@ fn main() {
 
         if input.mouse_is_down(MouseButton::Left) {
             // Mouse was pressed
-            let (x, y) = input.mouse_pos;
+            let (mut x, mut y) = input.mouse_pos;
+            x = cmp::min(x, WIDTH - 1);
+            y = cmp::min(y, HEIGHT - 1);
             cells[y * WIDTH + x] = true;
             fb.update_buffer(&cells);
             // Give the user extra time to make something pretty each time they click

src/breakout.rs

@@ -16,7 +16,9 @@ pub struct GlutinBreakout {
 }
 
 pub struct BasicInput {
-    /// The mouse position in buffer coordinates
+    /// The mouse position in buffer coordinates.
+    ///
+    /// The bottom left of the window is (0, 0).
     pub mouse_pos: (usize, usize),
     /// Stores whether a mouse button was down and is down, in that order.
     ///

src/core.rs

@@ -307,7 +307,11 @@ impl Internal {
                 let (x, y): (f64, f64) = pos.to_physical(dpi_factor).into();
                 let x_scale = self.fb.buffer_width as f64 / (self.fb.vp_width as f64);
                 let y_scale = self.fb.buffer_height as f64 / (self.fb.vp_height as f64);
-                let mouse_pos = ((x * x_scale).floor() as usize, (y * y_scale).floor() as usize);
+                let mut mouse_pos = (
+                    (x * x_scale).floor() as usize,
+                    // use the OpenGL texture coordinate system instead of window coordinates
+                    (self.fb.buffer_height as f64 - y * y_scale).floor() as usize
+                );
                 input.mouse_pos = mouse_pos;
             }
 

src/lib.rs

@@ -307,7 +307,8 @@ impl MiniGlFb {
     /// Provides an easy interface for rudimentary input handling.
     ///
     /// Automatically handles close events and partially handles resizes (the caller chooses if
-    /// a redraw is necessary).
+    /// a redraw is necessary; and the window will only actually physically change size if it is
+    /// a resizable window).
     ///
     /// Polls for window events and summarizes the input events for you each frame. See
     /// `BasicInput` for the information that is provided to you. You will need to use some