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| <!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Move Rhombus by Mouse. WebGL 1.0, JavaScript</title>
<script src="https://cdnjs.cloudflare.com/ajax/libs/gl-matrix/2.8.1/gl-matrix-min.js"></script>
<style>
#renderCanvas {
position: absolute;
left: 20px;
top: 20px;
z-index: 1;
border: 1px solid #aaaafa;
}
#hud {
position: absolute;
left: 20px;
top: 20px;
z-index: 3;
}
</style>
</head>
<body>
<canvas id="renderCanvas" width="290" height="290"></canvas>
<canvas id="hud" width="290" height="290"></canvas>
<script>
var vertexShaderSource = [
"attribute vec2 aPosition;",
"uniform mat4 uModelMatrix;",
"uniform mat4 uProjMatrix;",
"void main()",
"{",
" gl_Position = uProjMatrix * uModelMatrix * vec4(aPosition, 0.0, 1.0);",
"}"
].join("\n");
var fragmentShaderSource = [
"void main()",
"{",
" gl_FragColor = vec4(1.0, 0.0, 0.0, 1.0);",
"}"
].join("\n");
var hud = document.getElementById("hud");
var ctx = hud.getContext("2d");
ctx.font = "20px Georgia";
var canvas = document.getElementById("renderCanvas");
var gl = canvas.getContext("webgl");
var isLeftButtonPressed = false;
var isRightButtonPressed = false;
document.addEventListener("contextmenu", function(event) { event.preventDefault(); });
hud.onmousedown = function(event)
{
if (event.which === 1)
{
isLeftButtonPressed = true;
isRightButtonPressed = false;
ctx.clearRect(0, 0, hud.width, hud.height);
ctx.fillText("Левая кнопка зажата.", hud.width - 250, hud.height - 50);
ctx.fillText("Left button is pressed.", hud.width - 250, hud.height - 25);
}
else if (event.which === 3)
{
isLeftButtonPressed = false;
isRightButtonPressed = true;
ctx.clearRect(0, 0, hud.width, hud.height);
ctx.fillText("Правая кнопка зажата.", hud.width - 250, hud.height - 50);
ctx.fillText("Right button is pressed.", hud.width - 250, hud.height - 25);
}
}
hud.onmouseup = function(event)
{
if (event.which === 1)
{
isLeftButtonPressed = false;
isRightButtonPressed = false;
ctx.clearRect(0, 0, hud.width, hud.height);
}
else if (event.which === 3)
{
isLeftButtonPressed = false;
isRightButtonPressed = false;
ctx.clearRect(0, 0, hud.width, hud.height);
}
}
var vShader = gl.createShader(gl.VERTEX_SHADER);
gl.shaderSource(vShader, vertexShaderSource);
gl.compileShader(vShader);
var fShader = gl.createShader(gl.FRAGMENT_SHADER);
gl.shaderSource(fShader, fragmentShaderSource);
gl.compileShader(fShader);
var program = gl.createProgram();
gl.attachShader(program, vShader);
gl.attachShader(program, fShader);
gl.linkProgram(program);
gl.useProgram(program);
var vertCoords = [
0, 1,
-0.5, 0,
0, -1,
0.5, 0
];
var vbo = gl.createBuffer();
gl.bindBuffer(gl.ARRAY_BUFFER, vbo);
gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(vertCoords), gl.STATIC_DRAW);
var aPositionLoc = gl.getAttribLocation(program, "aPosition");
gl.vertexAttribPointer(aPositionLoc, 2, gl.FLOAT, false, 0, 0);
gl.enableVertexAttribArray(aPositionLoc);
var uModelMatrixLoc = gl.getUniformLocation(program, "uModelMatrix");
var modelMatrix = mat4.create();
var uProjMatrixLoc = gl.getUniformLocation(program, "uProjMatrix");
var projMatrix = mat4.ortho(mat4.create(), -100, 100, -100, 100, 10, -10);
gl.uniformMatrix4fv(uProjMatrixLoc, false, projMatrix);
gl.clearColor(1, 1, 1, 1);
window.requestAnimationFrame(animationLoop);
var x = 0;
var y = 0;
var speed = 1;
function animationLoop()
{
if (isLeftButtonPressed)
{
speed = Math.abs(speed);
x += speed;
y += speed;
}
else if (isRightButtonPressed)
{
speed = -Math.abs(speed);
x += speed;
y += speed;
}
mat4.identity(modelMatrix);
mat4.translate(modelMatrix, modelMatrix, vec3.fromValues(x, y, 0));
mat4.scale(modelMatrix, modelMatrix, vec3.fromValues(50, 50, 1));
gl.uniformMatrix4fv(uModelMatrixLoc, false, modelMatrix);
gl.clear(gl.COLOR_BUFFER_BIT);
gl.drawArrays(gl.LINE_LOOP, 0, vertCoords.length / 2);
window.requestAnimationFrame(animationLoop);
}
</script>
</body>
</html> |
