WIP: firing arcs: draw line to edge of map

index.js

@@ -1,5 +1,6 @@
 var rect = document.querySelector('rect#map');
 var toFixed = n => Number.parseFloat(n).toFixed(2);
+var radToDeg = radians => radians * 180 / Math.PI;
 
 var svgns = "http://www.w3.org/2000/svg",
     svg = document.querySelector('svg');
@@ -9,16 +10,81 @@ rect.addEventListener('mousemove', e => {
   var x = e.clientX - rect.left; // x position within the element
   var y = e.clientY - rect.top;  // y position within the element
 
-  console.log(
+  // console.log(
-    'x: ' + toFixed(x / rect.width * e.target.width.baseVal.valueInSpecifiedUnits) + '"',
+  //   'x: ' + toFixed(x / rect.width * e.target.width.baseVal.valueInSpecifiedUnits) + '"',
-    'y: ' + toFixed(y / rect.height * e.target.height.baseVal.valueInSpecifiedUnits) + '"'
+  //   'y: ' + toFixed(y / rect.height * e.target.height.baseVal.valueInSpecifiedUnits) + '"'
-  );
+  // );
 
   let aim = document.querySelector('.firing-arc.active');
 
   if (aim) {
     aim.setAttributeNS(null, 'x2', `${x / rect.width * e.target.width.baseVal.valueInSpecifiedUnits}in`);
     aim.setAttributeNS(null, 'y2', `${y / rect.height * e.target.height.baseVal.valueInSpecifiedUnits}in`);
+
+    let w = aim.x2.baseVal.value - aim.x1.baseVal.value;
+    let h = -(aim.y2.baseVal.value - aim.y1.baseVal.value);
+    let angle = radToDeg(Math.atan(h / w));
+
+    if (w < 0 && h > 0) {
+      angle = 180 - Math.abs(angle);
+    } else if (w < 0 && h < 0) {
+      angle = 180 + Math.abs(angle);
+    } else if (w > 0 && h < 0) {
+      angle = 360 - Math.abs(angle);
+    }
+
+    console.log(`${toFixed(angle)}\u00B0`);
+
+    let [x1, y1, x2, y2] = [aim.x1, aim.y1, aim.x2, aim.y2].map(v => v.baseVal.valueInSpecifiedUnits);
+    let [width, height] = [e.target.width, e.target.height].map(v => v.baseVal.valueInSpecifiedUnits);
+
+    console.log(`(${x2 - x1}, ${y2 - y1})`);
+
+    if (x2 - x1 > 0 && y2 - y1 > 0) {
+      let yWhenXisMax = (width - x1) * (y2 - y1) / (x2 - x1) + y1;
+      let xWhenYisMax = (height - y1) * (x2 - x1) / (y2 - y1) + x1;
+
+      if (xWhenYisMax <= width) {
+        aim.setAttributeNS(null, 'x2', `${xWhenYisMax}in`);
+        aim.setAttributeNS(null, 'y2', `${height}in`);
+      } else {
+        aim.setAttributeNS(null, 'x2', `${width}in`);
+        aim.setAttributeNS(null, 'y2', `${yWhenXisMax}in`);
+      }
+    } else if (x2 - x1 > 0 && y2 - y1 < 0) {
+      let yWhenXisMax = (width - x1) * (y2 - y1) / (x2 - x1) + y1;
+      let xWhenYisZero = (0 - y1) * (x2 - x1) / (y2 - y1) + x1;
+
+      if (xWhenYisZero <= width) {
+        aim.setAttributeNS(null, 'x2', `${xWhenYisZero}in`);
+        aim.setAttributeNS(null, 'y2', `0`);
+      } else {
+        aim.setAttributeNS(null, 'x2', `${width}in`);
+        aim.setAttributeNS(null, 'y2', `${yWhenXisMax}in`);
+      }
+    } else if (x2 - x1 < 0 && y2 - y1 < 0) {
+      let yWhenXisZero = (0 - x1) * (y2 - y1) / (x2 - x1) + y1;
+      let xWhenYisZero = (0 - y1) * (x2 - x1) / (y2 - y1) + x1;
+
+      if (yWhenXisZero >= 0) {
+        aim.setAttributeNS(null, 'x2', `0`);
+        aim.setAttributeNS(null, 'y2', `${yWhenXisZero}in`);
+      } else {
+        aim.setAttributeNS(null, 'x2', `${xWhenYisZero}in`);
+        aim.setAttributeNS(null, 'y2', `0`);
+      }
+    } else {
+      let yWhenXisZero = (0 - x1) * (y2 - y1) / (x2 - x1) + y1;
+      let xWhenYisMax = (height - y1) * (x2 - x1) / (y2 - y1) + x1;
+
+      if (yWhenXisZero <= height) {
+        aim.setAttributeNS(null, 'x2', `0`);
+        aim.setAttributeNS(null, 'y2', `${yWhenXisZero}in`);
+      } else {
+        aim.setAttributeNS(null, 'x2', `${xWhenYisMax}in`);
+        aim.setAttributeNS(null, 'y2', `${height}in`);
+      }
+    }
   }
 });
 
@@ -60,6 +126,7 @@ document.querySelector('#set-firing-arc').addEventListener('click', e => {
     aim.setAttributeNS(null, 'y1', counter.cy.baseVal.valueAsString);
     aim.setAttributeNS(null, 'x2', counter.cx.baseVal.valueAsString);
     aim.setAttributeNS(null, 'y2', counter.cy.baseVal.valueAsString);
+    // aim.style.transformOrigin = `${counter.cx.baseVal.valueAsString} ${counter.cy.baseVal.valueAsString}`;
 
     svg.appendChild(aim);
 
@@ -140,19 +207,27 @@ let getPointCoords = (x, y) => {
 
 
 let smallArc = document.createElementNS(svgns, 'polygon');
+smallArc.setAttributeNS(null, 'id', 'small-arc');
 let smallArcPoints = `${getPointCoords(1, 24)} ${getPointCoords(1, 21)} ${getPointCoords(2, 21)}`;
 smallArc.setAttributeNS(null, 'points', smallArcPoints);
 
 svg.appendChild(smallArc);
 
 let medArc = document.createElementNS(svgns, 'polygon');
+medArc.setAttributeNS(null, 'id', 'med-arc');
 let medArcPoints = `${getPointCoords(4, 24)} ${getPointCoords(3, 21)} ${getPointCoords(6, 21)}`;
 medArc.setAttributeNS(null, 'points', medArcPoints);
 
 svg.appendChild(medArc);
 
 let lrgArc = document.createElementNS(svgns, 'polygon');
+lrgArc.setAttributeNS(null, 'id', 'lrg-arc');
 let lrgArcPoints = `${getPointCoords(19, 24)} ${getPointCoords(9, 21)} ${getPointCoords(30, 21)}`;
 lrgArc.setAttributeNS(null, 'points', lrgArcPoints);
 
-svg.appendChild(lrgArc);
+svg.appendChild(lrgArc);
+
+arc = document.querySelector('#med-arc');
+let [ox, oy] = getPointCoords(4, 24);
+arc.style.transformOrigin = `${ox}px ${oy}px`;
+arc.style.transform = 'rotate(90deg)';

style.css

@@ -39,6 +39,7 @@ polygon {
 
 line.firing-arc {
   stroke: black;
+  /* transform: scale(2); */
 }
 
 image#img1 {