使用MFC的Wu反走样算法扫描转换起点在(100,100)终点在(500,300)的直线
时间: 2023-05-30 11:06:47 浏览: 231
直线段的扫描转换算法
以下是使用MFC的Wu反走样算法扫描转换起点在(100,100)终点在(500,300)的直线的示例代码:
```c++
void CMFCApplication1View::DrawLine(int x1, int y1, int x2, int y2, COLORREF color)
{
// Calculate line parameters
int dx = x2 - x1;
int dy = y2 - y1;
int steps = abs(dx) > abs(dy) ? abs(dx) : abs(dy);
float xIncrement = (float)dx / (float)steps;
float yIncrement = (float)dy / (float)steps;
float x = (float)x1;
float y = (float)y1;
// Draw each pixel on the line
for (int i = 0; i <= steps; i++)
{
// Calculate pixel coordinates
int xi = (int)x;
int yi = (int)y;
// Calculate pixel color based on Wu antialiasing algorithm
COLORREF pixelColor = color;
if (dx == 0 || dy == 0 || i == steps) // Endpoint or vertical/horizontal line
{
pixelColor = color;
}
else // Diagonal line
{
float gradient = (float)dy / (float)dx;
int alpha = (int)(255.0f * (1.0f - (y - yi)));
int beta = (int)(255.0f * (y - yi));
int gamma = (int)(255.0f * (1.0f - (x - xi)));
int delta = (int)(255.0f * (x - xi));
COLORREF pixelColor1 = RGB(GetRValue(color), GetGValue(color), GetBValue(color));
COLORREF pixelColor2 = RGB(GetRValue(color), GetGValue(color), GetBValue(color));
if (gradient > 0)
{
pixelColor1 = RGB(GetRValue(color), GetGValue(color), GetBValue(color));
pixelColor2 = RGB(GetRValue(color), GetGValue(color), GetBValue(color));
pixelColor1 = RGB(GetRValue(pixelColor1), GetGValue(pixelColor1), GetBValue(pixelColor1) - alpha);
pixelColor2 = RGB(GetRValue(pixelColor2), GetGValue(pixelColor2), GetBValue(pixelColor2) + beta);
}
else
{
pixelColor1 = RGB(GetRValue(color), GetGValue(color), GetBValue(color));
pixelColor2 = RGB(GetRValue(color), GetGValue(color), GetBValue(color));
pixelColor1 = RGB(GetRValue(pixelColor1), GetGValue(pixelColor1) - alpha, GetBValue(pixelColor1));
pixelColor2 = RGB(GetRValue(pixelColor2), GetGValue(pixelColor2) + beta, GetBValue(pixelColor2));
}
pixelColor = RGB(
(GetRValue(pixelColor1) * gamma + GetRValue(pixelColor2) * delta) / 255,
(GetGValue(pixelColor1) * gamma + GetGValue(pixelColor2) * delta) / 255,
(GetBValue(pixelColor1) * gamma + GetBValue(pixelColor2) * delta) / 255);
}
// Set pixel color
SetPixel(xi, yi, pixelColor);
// Move to next pixel
x += xIncrement;
y += yIncrement;
}
}
void CMFCApplication1View::OnDraw(CDC* pDC)
{
CMFCApplication1Doc* pDoc = GetDocument();
ASSERT_VALID(pDoc);
if (!pDoc)
return;
// Draw line from (100, 100) to (500, 300) using red color
DrawLine(100, 100, 500, 300, RGB(255, 0, 0));
}
```
该代码在MFC应用程序的视图类中实现,`DrawLine`函数接受起点和终点的坐标,以及颜色参数。该函数使用Wu反走样算法绘制直线,对于垂直/水平线和端点,直接使用指定的颜色,对于对角线线段,使用Wu算法计算颜色。在实现中,使用`SetPixel`函数设置每个像素颜色。在`OnDraw`函数中调用`DrawLine`函数以绘制直线。
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