From 12008b53a06a1f27882c98f618458536f982e404 Mon Sep 17 00:00:00 2001
From: Matthieu Baumann <matthieu.baumann@astro.unistra.fr>
Date: Tue, 16 Mar 2021 17:30:26 +0100
Subject: [PATCH] scissor

---
 src/core/src/camera/viewport.rs | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/src/core/src/camera/viewport.rs b/src/core/src/camera/viewport.rs
index 886064f1..c32b588c 100644
--- a/src/core/src/camera/viewport.rs
+++ b/src/core/src/camera/viewport.rs
@@ -80,7 +80,7 @@ fn set_canvas_size(gl: &WebGl2Context, width: u32, height: u32) {
     canvas.set_width(width);
     canvas.set_height(height);
     gl.viewport(0, 0, width as i32, height as i32);
-    gl.scissor(0, 0, width as i32, height as i32);
+    //gl.scissor(0, 0, width as i32, height as i32);
 }
 
 use crate::math;
@@ -117,6 +117,7 @@ impl CameraViewPort {
             .as_f64()
             .unwrap() as f32;
         set_canvas_size(&gl, width as u32, height as u32);
+        gl.scissor(0, 0, width as i32, height as i32);
 
         let aspect = width / height;
         let ndc_to_clip = P::compute_ndc_to_clip_factor(width as f64, height as f64);
@@ -184,6 +185,7 @@ impl CameraViewPort {
         self.aspect = width / height;
 
         set_canvas_size(&self.gl, width as u32, height as u32);
+        self.update_scissor();
 
         // Compute the new clip zoom factor
         self.ndc_to_clip = P::compute_ndc_to_clip_factor(width as f64, height as f64);
@@ -256,6 +258,17 @@ impl CameraViewPort {
         self.is_allsky = !P::is_included_inside_projection(
             &crate::renderable::projection::ndc_to_clip_space(&Vector2::new(-1.0, -1.0), self),
         );
+
+        self.update_scissor();
+    }
+
+    fn update_scissor(&mut self) {
+        let a = crate::renderable::projection::clip_to_screen_space(&Vector2::new(-1.0, 1.0), self);
+        let b = crate::renderable::projection::clip_to_screen_space(&Vector2::new(1.0, -1.0), self);
+
+        let w = (b.x - a.x).abs();
+        let h = (b.y - a.y).abs();
+        self.gl.scissor(a.x as i32, a.y as i32, w as i32, h as i32);
     }
 
     pub fn rotate<P: Projection>(&mut self, axis: &cgmath::Vector3<f64>, angle: Angle<f64>) {