关于MIDP2.0下像数碰撞如何获取碰撞点的坐标
看了SPRITE类后，发现它里面有一个方法（如下），能计算出碰撞点的坐标，但是这个方法是私有的，我该如何调用这个方法呢？如果重写该方法，transform1，transform2是多少呢？
private static boolean doPixelCollision(int image1XOffset,
int image1YOffset,
int image2XOffset,
int image2YOffset,
Image image1, int transform1,
Image image2, int transform2,
int width, int height) {
// starting point of comparison
int startY1;
// x and y increments
int xIncr1, yIncr1;
// .. for image 2
int startY2;
int xIncr2, yIncr2;
int numPixels = height * width;
int[] argbData1 = new int[numPixels];
int[] argbData2 = new int[numPixels];
if (0x0 != (transform1 & INVERTED_AXES)) {
// inverted axes
// scanlength = height
if (0x0 != (transform1 & Y_FLIP)) {
xIncr1 = -(height); // - scanlength
startY1 = numPixels - height; // numPixels - scanlength
} else {
xIncr1 = height; // + scanlength
startY1 = 0;
}
if (0x0 != (transform1 & X_FLIP)) {
yIncr1 = -1;
startY1 += (height - 1);
} else {
yIncr1 = +1;
}
image1.getRGB(argbData1, 0, height, // scanlength = height
image1XOffset, image1YOffset, height, width);
} else {
// scanlength = width
if (0x0 != (transform1 & Y_FLIP)) {
startY1 = numPixels - width; // numPixels - scanlength
yIncr1 = -(width); // - scanlength
} else {
startY1 = 0;
yIncr1 = width; // + scanlength
}
if (0x0 != (transform1 & X_FLIP)) {
xIncr1 = -1;
startY1 += (width - 1);
} else {
xIncr1 = +1;
}
image1.getRGB(argbData1, 0, width, // scanlength = width
image1XOffset, image1YOffset, width, height);
}
if (0x0 != (transform2 & INVERTED_AXES)) {
// inverted axes
if (0x0 != (transform2 & Y_FLIP)) {
xIncr2 = -(height);
startY2 = numPixels - height;
} else {
xIncr2 = height;
startY2 = 0;
}
if (0x0 != (transform2 & X_FLIP)) {
yIncr2 = -1;
startY2 += height - 1;
} else {
yIncr2 = +1;
}
image2.getRGB(argbData2, 0, height,
image2XOffset, image2YOffset, height, width);
} else {
if (0x0 != (transform2 & Y_FLIP)) {
startY2 = numPixels - width;
yIncr2 = -(width);
} else {
startY2 = 0;
yIncr2 = +width;
}
if (0x0 != (transform2 & X_FLIP)) {
xIncr2 = -1;
startY2 += (width - 1);
} else {
xIncr2 = +1;
}
image2.getRGB(argbData2, 0, width,
image2XOffset, image2YOffset, width, height);
}
int x1, x2;
int xLocalBegin1, xLocalBegin2;
// the loop counters
int numIterRows;
int numIterColumns;
for (numIterRows = 0, xLocalBegin1 = startY1, xLocalBegin2 = startY2;
numIterRows < height;
xLocalBegin1 += yIncr1, xLocalBegin2 += yIncr2, numIterRows++) {
for (numIterColumns = 0, x1 = xLocalBegin1, x2 = xLocalBegin2;
numIterColumns < width;
x1 += xIncr1, x2 += xIncr2, numIterColumns++) {
if (((argbData1[x1] & ALPHA_BITMASK) != 0) &&
((argbData2[x2] & ALPHA_BITMASK) != 0)) {
return true;
}
} // end for x
} // end for y
// worst case! couldn't find a single colliding pixel!
return false;
}
[解决办法]
//检测相交
private boolean retCollision(int x1,int y1,int x1width,int y1height,int x2,int y2,int x2width,int y2height){
if((x1>x2-x1width&x1<x2+x2width)&(y1>y2-y1height&y1<y2+y2height))return true;
return false;
}
[解决办法]
碰撞 不一定要求非常准确!
只要测试效果好,就好!
[解决办法]
你可以定义一个很小的碰撞检测的矩形来解决你这个问题
