Bring 2.0 stroke ordering fixes to 1.x

Author: davepagurek

src/webgl/shaders/line.frag

@@ -1,4 +1,5 @@
-precision mediump int;
+precision highp int;
+precision highp float;
 
 uniform vec4 uMaterialColor;
 uniform int uStrokeCap;

src/webgl/shaders/line.vert

@@ -18,7 +18,8 @@
 
 #define PROCESSING_LINE_SHADER
 
-precision mediump int;
+precision highp int;
+precision highp float;
 
 uniform mat4 uModelViewMatrix;
 uniform mat4 uProjectionMatrix;
@@ -116,7 +117,7 @@ void main() {
 
   // Moving vertices slightly toward camera when far away 
   // https://github.com/processing/p5.js/issues/6956 
-  float zOffset = mix(-0.00045, -1., facingCamera);
+  float zOffset = mix(0., -1., facingCamera);
   float dynamicZAdjustment = mix(0.0, zOffset, distanceFactor); // Closer = less zAdjustment, farther = more
 
   posp.z -= dynamicZAdjustment;

test/unit/visual/cases/webgl.js

@@ -128,4 +128,17 @@ visualSuite('WebGL', function() {
       }
     );
   });
+
+  visualSuite('Strokes', function() {
+    visualTest('Strokes do not cut into fills in ortho mode', (p5, screenshot) => {
+      p5.createCanvas(50, 50, p5.WEBGL);
+      p5.background(220);
+      p5.stroke(8);
+      p5.ortho();
+      p5.rotateX(p5.PI/4);
+      p5.rotateY(p5.PI/4);
+      p5.box(30);
+      screenshot();
+    });
+  });
 });

test/unit/visual/screenshots/WebGL/Strokes/Strokes do not cut into fills in ortho mode/000.png

@@ -0,0 +1,3 @@
+{
+  "numScreenshots": 1
+}