From f5fa572ab70664129ae8c2d81665752f0f8f7f88 Mon Sep 17 00:00:00 2001
From: Syndamia <kamen@syndamia.com>
Date: Sat, 26 Aug 2023 13:59:14 +0300
Subject: [WGL/P] Properly implemented ray tracing, though there are issues

---
 .../Project/Project.html                           | 25 ++++++++++++++++++++--
 1 file changed, 23 insertions(+), 2 deletions(-)

(limited to 'Year 2/Computer Graphics with WebGL/Project/Project.html')

diff --git a/Year 2/Computer Graphics with WebGL/Project/Project.html b/Year 2/Computer Graphics with WebGL/Project/Project.html
index a97f94e..cf55554 100644
--- a/Year 2/Computer Graphics with WebGL/Project/Project.html	
+++ b/Year 2/Computer Graphics with WebGL/Project/Project.html	
@@ -78,6 +78,9 @@ h2 {
 			init();
 		}
 
+		const PERSPECTIVE_ANGLE = 30;
+		const PERSPECTIVE_NEAR = 1;
+
 		function init()
 		{
 			gl = getContext("picasso");
@@ -91,7 +94,7 @@ h2 {
 			gl.blendFunc(gl.SRC_ALPHA, gl.ONE_MINUS_SRC_ALPHA);
 
 			identity();
-			perspective(30,gl.canvas.width/gl.canvas.height,1,40000);
+			perspective(PERSPECTIVE_ANGLE,gl.canvas.width/gl.canvas.height,PERSPECTIVE_NEAR,40000);
 			gl.uniform1i(uUseNormalMatrix,false);
 
 			gl.uniform3f(uAmbientColor,0.3,0.3,0.3);
@@ -122,7 +125,16 @@ h2 {
 			gl.canvas.height = gl.canvas.offsetHeight;
 			gl.viewport(0,0,gl.canvas.width,gl.canvas.height);
 
-			// gl.uniform2f(uViewPort, gl.canvas.width, gl.canvas.height);
+			// (Look at Presentation 6, Slide 21, the prespective projection diagram)
+			// Since we're gonna be raycasting, we need to know where the near side is and it's
+			// dimentions in our coordinate system, so we can offset the rays properly.
+			// First, we pass the viewPort to convert our pixel coordinates to percentage of the
+			// screen.
+			gl.uniform2f(uViewPort, gl.canvas.width, gl.canvas.height);
+			w = 2 * Math.tan(PERSPECTIVE_ANGLE / 360 * Math.PI) * PERSPECTIVE_NEAR;
+			// The height of the near wall is determined by the aspect ratio.
+			gl.uniform2f(uPerspSize, w, gl.canvas.height / gl.canvas.width * w);
+			gl.uniform1f(uPerspDist, PERSPECTIVE_NEAR);
 
 			drawFrame();
 		}
@@ -143,6 +155,15 @@ h2 {
 
 			requestAnimationFrame(drawFrame);
 		}
+		document.addEventListener('keypress', (e) => {
+			if (e.key == 'u') {
+				console.log(w);
+				console.log(w*gl.canvas.height / gl.canvas.width);
+				console.log(forward.toCartesian());
+				console.log(left.toCartesian());
+				console.log(up.toCartesian());
+			}
+		});
 	</script>
 </head>
 
-- 
cgit v1.3.1-23-gd82d