70 lines
1.9 KiB
Dart
70 lines
1.9 KiB
Dart
class ViewRect {
|
|
final double left;
|
|
final double top;
|
|
final double right;
|
|
final double bottom;
|
|
|
|
const ViewRect(this.left, this.top, this.right, this.bottom);
|
|
|
|
double get width => right - left;
|
|
double get height => bottom - top;
|
|
double get centerX => (left + right) / 2;
|
|
double get centerY => (top + bottom) / 2;
|
|
}
|
|
|
|
/// 模型归一化坐标 → 预览视图坐标（含传感器旋转与 FIT_CENTER 裁剪）。
|
|
class CoordinateMapper {
|
|
static ViewRect mapToView(
|
|
double normLeft,
|
|
double normTop,
|
|
double normRight,
|
|
double normBottom,
|
|
int rotation,
|
|
int imageW,
|
|
int imageH,
|
|
double viewW,
|
|
double viewH,
|
|
) {
|
|
// 1) 旋转校正：图像方向 → 竖屏视图方向（归一化坐标）
|
|
late final double x0, y0, x1, y1;
|
|
switch (rotation) {
|
|
case 90:
|
|
x0 = 1 - normBottom;
|
|
y0 = normLeft;
|
|
x1 = 1 - normTop;
|
|
y1 = normRight;
|
|
case 180:
|
|
x0 = 1 - normRight;
|
|
y0 = 1 - normBottom;
|
|
x1 = 1 - normLeft;
|
|
y1 = 1 - normTop;
|
|
case 270:
|
|
x0 = normTop;
|
|
y0 = 1 - normRight;
|
|
x1 = normBottom;
|
|
y1 = 1 - normLeft;
|
|
default:
|
|
x0 = normLeft;
|
|
y0 = normTop;
|
|
x1 = normRight;
|
|
y1 = normBottom;
|
|
}
|
|
// 2) 旋转后图像在竖屏方向上的尺寸
|
|
final portrait = rotation == 90 || rotation == 270;
|
|
final portW = portrait ? imageH : imageW;
|
|
final portH = portrait ? imageW : imageH;
|
|
// 3) FIT_CENTER 缩放与居中偏移
|
|
final scale = viewW / portW < viewH / portH
|
|
? viewW / portW
|
|
: viewH / portH;
|
|
final offsetX = (viewW - portW * scale) / 2;
|
|
final offsetY = (viewH - portH * scale) / 2;
|
|
return ViewRect(
|
|
x0 * portW * scale + offsetX,
|
|
y0 * portH * scale + offsetY,
|
|
x1 * portW * scale + offsetX,
|
|
y1 * portH * scale + offsetY,
|
|
);
|
|
}
|
|
}
|