android绘图坐标

在android中，手机的屏幕大少为320*480，原点坐标在左上角(0,0)，在绘制图形时一定要非常清楚要绘制的图形对坐标转换的关系。

简单的图形如，直线，画点，画圆大家可能不会有什么问题，但如果遇到复杂图形或图形旋转等情况时，比较游戏俄罗斯方块中，对不同组合的方块进行变换时，涉及到很多坐标变换情况，如果不是完全清楚的话，很难编码了。

如下：

引用

public int[][] rotateStone(int[][] currentPosition) {
int[][] newPosition = new int[4][2];
int x, y;
switch (blockID) {
case 2:
if (rotatePosition == 0) {//一横变一竖
x = currentPosition[3][0];
y = currentPosition[3][1];
newPosition[0][0] = x - 3;
newPosition[0][1] = y;
newPosition[1][0] = x - 2;
newPosition[1][1] = y;
newPosition[2][0] = x - 1;
newPosition[2][1] = y;
newPosition[3][0] = x;
newPosition[3][1] = y;
rotatePosition = 1;
} else {//反之
x = currentPosition[3][0];
y = currentPosition[3][1];
newPosition[0][0] = x;
newPosition[0][1] = y - 3;
newPosition[1][0] = x;
newPosition[1][1] = y - 2;
newPosition[2][0] = x;
newPosition[2][1] = y - 1;
newPosition[3][0] = x;
newPosition[3][1] = y;
rotatePosition = 0;
}
return newPosition;
case 3:
if (rotatePosition == 0) {//左T
x = currentPosition[2][0];
y = currentPosition[2][1];
newPosition[0][0] = x;
newPosition[0][1] = y - 1;
newPosition[1][0] = x;
newPosition[1][1] = y + 1;
newPosition[2][0] = x;
newPosition[2][1] = y;
newPosition[3][0] = x + 1;
newPosition[3][1] = y;
rotatePosition = 1;
} else if (rotatePosition == 1) {//上T
x = currentPosition[2][0];
y = currentPosition[2][1];
newPosition[0][0] = x;
newPosition[0][1] = y + 1;
newPosition[1][0] = x - 1;
newPosition[1][1] = y;
newPosition[2][0] = x;
newPosition[2][1] = y;
newPosition[3][0] = x + 1;
newPosition[3][1] = y;
rotatePosition = 2;
} else if (rotatePosition == 2) {//右T
x = currentPosition[2][0];
y = currentPosition[2][1];
newPosition[0][0] = x;
newPosition[0][1] = y - 1;
newPosition[1][0] = x - 1;
newPosition[1][1] = y;
newPosition[2][0] = x;
newPosition[2][1] = y;
newPosition[3][0] = x;
newPosition[3][1] = y + 1;
rotatePosition = 3;
} else if (rotatePosition == 3) {//下T
x = currentPosition[2][0];
y = currentPosition[2][1];
newPosition[0][0] = x - 1;
newPosition[0][1] = y;
newPosition[1][0] = x + 1;
newPosition[1][1] = y;
newPosition[2][0] = x;
newPosition[2][1] = y;
newPosition[3][0] = x;
newPosition[3][1] = y - 1;
rotatePosition = 0;
}
return newPosition;
case 4:
if (rotatePosition == 0) {//上右7
x = currentPosition[2][0];
y = currentPosition[2][1];
newPosition[0][0] = x;
newPosition[0][1] = y;
newPosition[1][0] = x + 1;
newPosition[1][1] = y;
newPosition[2][0] = x + 2;
newPosition[2][1] = y;
newPosition[3][0] = x + 2;
newPosition[3][1] = y - 1;
rotatePosition = 1;
} else if (rotatePosition == 1) {//左上T
x = currentPosition[2][0];
y = currentPosition[2][1];
newPosition[0][0] = x - 1;
newPosition[0][1] = y - 2;
newPosition[1][0] = x;
newPosition[1][1] = y - 2;
newPosition[2][0] = x;
newPosition[2][1] = y - 1;
newPosition[3][0] = x;
newPosition[3][1] = y;
rotatePosition = 2;
} else if (rotatePosition == 2) {//下左7
x = currentPosition[1][0];
y = currentPosition[1][1];
newPosition[0][0] = x - 2;
newPosition[0][1] = y + 1;
newPosition[1][0] = x - 2;
newPosition[1][1] = y;
newPosition[2][0] = x - 1;
newPosition[2][1] = y;
newPosition[3][0] = x;
newPosition[3][1] = y;
rotatePosition = 3;
} else if (rotatePosition == 3) {//左上
x = currentPosition[1][0];
y = currentPosition[1][1];
newPosition[0][0] = x;
newPosition[0][1] = y;
newPosition[1][0] = x;
newPosition[1][1] = y + 1;
newPosition[2][0] = x;
newPosition[2][1] = y + 2;
newPosition[3][0] = x + 1;
newPosition[3][1] = y + 2;
rotatePosition = 0;
}
return newPosition;
case 5:
if (rotatePosition == 0) {
x = currentPosition[1][0];
y = currentPosition[1][1];
newPosition[0][0] = x - 2;
newPosition[0][1] = y - 1;
newPosition[1][0] = x - 1;
newPosition[1][1] = y - 1;
newPosition[2][0] = x;
newPosition[2][1] = y - 1;
newPosition[3][0] = x;
newPosition[3][1] = y;
rotatePosition = 1;
} else if (rotatePosition == 1) {
x = currentPosition[0][0];
y = currentPosition[0][1];
newPosition[0][0] = x;
newPosition[0][1] = y;
newPosition[1][0] = x + 1;
newPosition[1][1] = y;
newPosition[2][0] = x;
newPosition[2][1] = y + 1;
newPosition[3][0] = x;
newPosition[3][1] = y + 2;
rotatePosition = 2;
} else if (rotatePosition == 2) {
x = currentPosition[2][0];
y = currentPosition[2][1];
newPosition[0][0] = x;
newPosition[0][1] = y;
newPosition[1][0] = x;
newPosition[1][1] = y + 1;
newPosition[2][0] = x + 1;
newPosition[2][1] = y + 1;
newPosition[3][0] = x + 2;
newPosition[3][1] = y + 1;
rotatePosition = 3;
} else if (rotatePosition == 3) {
x = currentPosition[2][0];
y = currentPosition[2][1];
newPosition[0][0] = x;
newPosition[0][1] = y;
newPosition[1][0] = x + 1;
newPosition[1][1] = y;
newPosition[2][0] = x + 1;
newPosition[2][1] = y - 1;
newPosition[3][0] = x + 1;
newPosition[3][1] = y - 2;
rotatePosition = 0;
}
return newPosition;
case 6:
if (rotatePosition == 0) {
x = currentPosition[2][0];
y = currentPosition[2][1];
newPosition[0][0] = x - 1;
newPosition[0][1] = y;
newPosition[1][0] = x;
newPosition[1][1] = y + 1;
newPosition[2][0] = x;
newPosition[2][1] = y;
newPosition[3][0] = x + 1;
newPosition[3][1] = y + 1;
rotatePosition = 1;
} else {
x = currentPosition[2][0];
y = currentPosition[2][1];

newPosition[0][0] = x;
newPosition[0][1] = y - 1;
newPosition[1][0] = x - 1;
newPosition[1][1] = y;
newPosition[2][0] = x;
newPosition[2][1] = y;
newPosition[3][0] = x - 1;
newPosition[3][1] = y + 1;
rotatePosition = 0;
}
return newPosition;
case 7:
if (rotatePosition == 0) {
x = currentPosition[2][0];
y = currentPosition[2][1];

newPosition[0][0] = x - 1;
newPosition[0][1] = y - 1;
newPosition[1][0] = x - 1;
newPosition[1][1] = y;
newPosition[2][0] = x;
newPosition[2][1] = y;
newPosition[3][0] = x;
newPosition[3][1] = y + 1;
rotatePosition = 1;
} else {
x = currentPosition[2][0];
y = currentPosition[2][1];

newPosition[0][0] = x + 1;
newPosition[0][1] = y;
newPosition[1][0] = x - 1;
newPosition[1][1] = y + 1;
newPosition[2][0] = x;
newPosition[2][1] = y;
newPosition[3][0] = x;
newPosition[3][1] = y + 1;
rotatePosition = 0;
}
return newPosition;
default:
return currentPosition;

}

}

以上代码就是俄罗斯方块中的图形变换。

这是其一，另外还要找准其旋转坐标点，方程变换。

(x,y), (x+1,y),(x+2, y)即为向屏幕x轴移动,(x,y),(x,y+1),(x,y+2)即为向屏幕y轴移动,其它一此类推。