gl: make viewport resize with windowgl/triangle

Keep it square, but make it so the sides of the viewport are equal to
shorter side of the window.

1 files changed, 21 insertions, 4 deletions

diff --git a/src/main.zig b/src/main.zig
index 564fe37..7543090 100644
--- a/src/main.zig
+++ b/src/main.zig
@@ -247,11 +247,28 @@ pub const Window = struct {
 
     /// Resize this window
     fn resize(win: *Window, width: i32, height: i32) !void {
-        win.height = if (height != 0) height else win.height;
-        win.width = if (width != 0) width else win.width;
-        if (width == 0 and height == 0) return;
+        const new_height = if (height != 0) height else win.height;
+        const new_width = if (width != 0) width else win.width;
+        if (win.width == new_width and win.height == new_height) return;
+
+        win.width = new_width;
+        win.height = new_height;
         win.egl_win.resize(win.width, win.height, 0, 0);
-        c.glViewport(@divTrunc(win.width, 2) - 160, @divTrunc(win.height, 2) - 160, 320, 320);
+        if (win.width < win.height) {
+            c.glViewport(
+                0,
+                @divTrunc(win.height, 2) - @divTrunc(win.width, 2),
+                win.width,
+                win.width,
+            );
+        } else {
+            c.glViewport(
+                @divTrunc(win.width, 2) - @divTrunc(win.height, 2),
+                0,
+                win.height,
+                win.height,
+            );
+        }
     }
 
     /// XDG Surface callbacks