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/*
* Copyright 2009, Google Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following disclaimer
* in the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Google Inc. nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/**
* @fileoverview This file contains functions used controlling the camera.
*
*/
/**
* Clamps a value between bounds.
*
* @param {number} inputValue Value to be clamped.
* @param {number} lowerBound Lower limit.
* @param {number} upperBound Upper limit.
* @return {number} The clamped value.
*/
function clamp(inputValue, lowerBound, upperBound) {
var resultValue = inputValue;
if (inputValue < lowerBound) resultValue = lowerBound;
if (inputValue > upperBound) resultValue = upperBound;
return resultValue;
}
/**
* Functions for control based on the mouse
*/
var dragging = false;
var g_rotX = 2.85;
var g_rotY = 0;
var g_thisClick;
var g_lastClick;
var g_cameraZoom = 1.0;
function startDragging(e) {
g_thisClick = e;
dragging = true;
}
/**
* Scroll wheel handler. Adjusts g_cameraZoom global according to wheel
* movement then causes a recalculation of the projection matrix.
* The goal is to simulate a zoom lens rather than to move the viewpoint.
* @param {Event} e Wheel event to handle.
*/
function scrollMe(e) {
if (e.deltaY) {
g_cameraZoom = clamp(g_cameraZoom * ((e.deltaY < 0 ? 13 : 11) / 12),
0.1,
4.0);
resize();
}
}
function drag(e) {
if (dragging) {
var scale = -.001 * g_cameraZoom;
g_lastClick = g_thisClick;
g_thisClick = e;
var xLowerLimit = 2.3;
var xUpperLimit = 4.2;
var yLowerLimit = -0.6;
var yUpperLimit = 0.25;
g_rotX = clamp(g_rotX - scale * (g_thisClick.x - g_lastClick.x),
xLowerLimit, xUpperLimit);
g_rotY = clamp(g_rotY + scale * (g_thisClick.y - g_lastClick.y),
yLowerLimit, yUpperLimit);
setViewFromRotation();
}
}
function setViewFromRotation() {
var rotMatX = g_math.matrix4.rotationY(g_rotX);
var right = g_math.matrix4.transformDirection(rotMatX, [0, 0, 1]);
var camera_X = g_math.normalize(g_math.cross([0, 1, 0], right));
var rotMatY = g_math.matrix4.axisRotation(camera_X, g_rotY);
var rot_mat = g_math.matrix4.mul(rotMatX, rotMatY);
g_root.identity();
// TODO: eye position should be a variable
var eye = [-2.751, 3.529, -8.563];
g_viewInfo.drawContext.view = g_math.matrix4.lookAt(
eye,
g_math.addVector(eye, g_math.mulVectorMatrix([0, 0, 1, 0], rot_mat)),
g_math.mulVectorMatrix([0, 1, 0, 0], rot_mat));
}
function stopDragging(e) {
dragging = false;
}
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