6 //context.font = "normal 20px sans-serif";
9 //context.fillStyle = "rgba(200,255,200,0.5)";
10 //context.strokeStyle = "rgba(0, 0, 0, 0.5)";
12 function drawText(gcontext, text, x, y)
15 //前景をstrokeStyleで塗りつぶした文字列を描画する
18 textsize = gcontext.measureText(text);
19 gcontext.fillRect(x, y, textsize.width, 20);
21 gcontext.fillStyle = gcontext.strokeStyle;
22 //fillText引数の座標は文字列の左下!
23 gcontext.fillText(text, x, y + 20 - 1);
27 function drawArcDegree(gcontext, radius, startAngleDegree, endAngleDegree, x, y, anticlockwise)
29 //半径radius, 中心座標(x,y)の円弧の、
30 //startAngleDegreeからendAngleDegreeまでの範囲を、
31 //(!anticlockwise)=時計回り
32 //(anticlockwise) =反時計回り
35 startAngleRadian = startAngleDegree * Math.PI / 180;
36 endAngleRadian = endAngleDegree * Math.PI / 180;
39 gcontext.arc(drawCoordinatesInInteger(x), drawCoordinatesInInteger(y), drawCoordinatesInInteger(radius), startAngleRadian, endAngleRadian, anticlockwise);
45 function fillRect(gContext, x, y, w, h)
47 gContext.fillRect(drawCoordinatesInInteger(x), drawCoordinatesInInteger(y), drawCoordinatesInInteger(w), drawCoordinatesInInteger(h));
50 function strokeRect(gContext, x, y, w, h)
52 gContext.strokeRect(drawCoordinatesInInteger(x), drawCoordinatesInInteger(y), drawCoordinatesInInteger(w), drawCoordinatesInInteger(h));
55 function drawCoordinatesInInteger(coordinateElement)
57 //from http://www.html5rocks.com/ja/tutorials/canvas/performance/
59 return ((0.5 + coordinateElement) | 0);