temp: 提交代码 含显示bug

OpenGL/src/WindowsProjectTest/WindowsProjectTest/Canvas.cpp

@@ -1 +1,75 @@
 #include "Canvas.h"
+#include <cmath>
+
+#include <Windows.h>
+#include <string>
+
+namespace GT {
+	void Canvas::drawLine(intV2 pt1, intV2 pt2, RGBA _Color) {
+		int disY = abs(pt2.y - pt1.y);
+		int disX = abs(pt2.x - pt1.x);
+
+		int xNow = pt1.x;
+		int yNow = pt1.y;
+
+		int stepX = 0;
+		int stepY = 0;
+
+		// 判断步径方向 
+		if (pt1.x < pt2.x) {
+			stepX = 1;
+		}
+		else {
+			stepX = -1;
+		}
+
+		if (pt1.y < pt2.y) {
+			stepY = 1;
+		}
+		else {
+			stepY = -1;
+		}
+
+		// 对比 x、y 偏移量，决定步径的方向选取 x 或者 y
+		int sumStep = disX;
+		bool useXStep = true;
+
+		if (disX < disY) {
+			// 表示斜率 > 1
+			sumStep = disY;
+			useXStep = false;
+			SWAP_INT(disX, disY);
+		}
+
+		// 初始化 p 值 也就是公式推导时最开始的值 (2dy - dx)
+		int p = 2 * disY - disX;
+
+		for (int index = 0; index < sumStep; ++ index) {
+			std::wstring str = L"index = " + std::to_wstring(index) + L" xNow = " + std::to_wstring(xNow) + L", yNow = " + std::to_wstring(yNow) + L"\n";
+			OutputDebugString(str.c_str());
+			drawPoint(xNow, yNow, _Color);
+			if (p >= 0) {
+				if (useXStep) {
+					yNow += stepY;
+				}
+				else {
+					xNow += stepX;
+				}
+
+				// (2dy - dx) + 2(dy - dx)
+				p += 2 * (disY - disX);
+			} else {
+				// (2dy - dx) + 2dy
+				p += 2 * disY;
+			}
+
+			// 更新步径坐标
+			if (useXStep) {
+				xNow += stepX;
+			}
+			else {
+				yNow += stepY;
+			}
+		}
+	}
+}

OpenGL/src/WindowsProjectTest/WindowsProjectTest/Canvas.h

@@ -27,6 +27,9 @@ namespace GT {
 
 		}
 
+		// »­Ïß
+		void drawLine(intV2 pt1, intV2 pt2, RGBA _Color);
+
 		// »­µã²Ù×÷
 		void drawPoint(int x, int y, RGBA _collor) {
 			if (x < 0 || x >= m_Width || y < 0 || y >= m_Height) {

OpenGL/src/WindowsProjectTest/WindowsProjectTest/WindowsProjectTest.cpp

@@ -31,9 +31,11 @@ INT_PTR CALLBACK    About(HWND, UINT, WPARAM, LPARAM);
 void Render() {
     _canvas->clear();
 
-    for (int x = 0; x < wWidth; ++x) {
-        _canvas->drawPoint(x, 200, GT::RGBA(255, 0, 0, 0));
-    }
+	//for (int x = 0; x < wWidth; ++x) {
+	//	_canvas->drawPoint(x, x, GT::RGBA(255, 0, 0, 0));
+	//}
+
+    _canvas->drawLine(GT::intV2(1, 1), GT::intV2(10, 10), GT::RGBA(255, 0, 0, 0));
 
 	// 将 hMem 的数据一次写入到 hDC 中
 	BitBlt(hDC, 0, 0, wWidth, wHeight, hMem, 0, 0, SRCCOPY);