3D坐标系转换示例源代码

#include "CPPYIN.3DLib.h" // 全局变量 IDirect3DDevice9* pDevice = 0; IDirect3DSurface9* pSurface = 0; D3DLOCKED_RECT lockedRect; bool _CPPYIN_3DLib::Init3DLib(HINSTANCE hInstance, HWND hWnd, int width, int height) { IDirect3D9* d3d9 = Direct3DCreate9(D3D_SDK_VERSION); D3DPRESENT_PARAMETERS d3dpp; d3dpp.BackBufferWidth = width; d3dpp.BackBufferHeight = height; d3dpp.BackBufferFormat = D3DFMT_A8R8G8B8; d3dpp.BackBufferCount = 1; d3dpp.MultiSampleType = D3DMULTISAMPLE_NONE; d3dpp.MultiSampleQuality = 0; d3dpp.SwapEffect = D3DSWAPEFFECT_DISCARD; d3dpp.hDeviceWindow = hWnd; d3dpp.Windowed = TRUE; d3dpp.EnableAutoDepthStencil = true; d3dpp.AutoDepthStencilFormat = D3DFMT_D24S8; d3dpp.Flags = 0; d3dpp.FullScreen_RefreshRateInHz = D3DPRESENT_RATE_DEFAULT; d3dpp.PresentationInterval = D3DPRESENT_INTERVAL_IMMEDIATE; d3d9->CreateDevice(D3DADAPTER_DEFAULT, D3DDEVTYPE_REF, hWnd, D3DCREATE_SOFTWARE_VERTEXPROCESSING, &d3dpp, &pDevice); d3d9->Release(); pDevice->CreateOffscreenPlainSurface(width, height, D3DFMT_A8R8G8B8, D3DPOOL_DEFAULT, &pSurface, 0); return true; } int _CPPYIN_3DLib::LockSurface() { memset(&lockedRect, 0, sizeof(lockedRect)); pSurface->LockRect(&lockedRect,NULL,D3DLOCK_DISCARD); return 1; } int _CPPYIN_3DLib::UnlockSurface() { pSurface->UnlockRect(); return 1; } int _CPPYIN_3DLib::DrawPixel(int x,int y, DWORD color) { DWORD* pBits = (DWORD*)lockedRect.pBits; pBits[x + y * (lockedRect.Pitch >> 2)] = color; return 1; } int _CPPYIN_3DLib::DrawLine(int x0, int y0, int x1, int y1, DWORD color) { int x, y, dx, dy, dx2, dy2, xstep, ystep, error, index; x = x0; y = y0; dx = x1 - x0; dy = y1 - y0; if (dx >= 0) // 从左往右画 { xstep = 1; // x步进正1 } else // 从右往左画 { xstep = -1; // x步进负1 dx = -dx; // 取绝对值 } if (dy >= 0) // 从上往下画 { ystep = 1; // y步进正1 } else // 从下往上画 { ystep = -1; // y步进负1 dy = -dy; // 取绝对值 } dx2 = dx << 1; // 2 * dx dy2 = dy << 1; // 2 * dy if (dx > dy) // 近X轴直线 { error = dy2 - dx; for (index = 0; index <= dx; ++index) { DrawPixel(x, y, color); if (error >= 0) { error -= dx2; y += ystep; } error += dy2; x += xstep; } } else // 近Y轴直线 { error = dx2 - dy; for (index = 0; index <= dy; ++index) { DrawPixel(x, y, color); if (error >= 0) { error -= dy2; x += xstep; } error += dx2; y += ystep; } } return 1; } // 返回1则有交点，返回0则无交点，无需画了 int _CPPYIN_3DLib::ClipLineByRect(int x1, int y1, int x2, int y2, RECT rect, int &nx1, int &ny1, int &nx2, int &ny2) { // 创建并设置起点p1和终点p2的位置代码p1code和p2code int p1code = 0; int p2code = 0; if (y1 < rect.top) p1code |= 8; else if (y1 > rect.bottom) p1code |= 4; if (x1 < rect.left) p1code |= 1; else if (x1 > rect.right) p1code |= 2; if (y2 < rect.top) p2code |= 8; else if (y2 > rect.bottom) p2code |= 4; if (x2 < rect.left) p2code |= 1; else if (x2 > rect.right) p2code |= 2; // 过滤同侧情况 if ((p1code & p2code)) return 0; // 完全保留 if (p1code == 0 && p2code == 0) { nx1 = x1; ny1 = y1; nx2 = x2; ny2 = y2; return 1; } // 计算np1的坐标nx1, ny1 switch(p1code) { case 0: // C { nx1 = x1; ny1 = y1; } break; case 8: // N { ny1 = rect.top; nx1 = int(x1 + (rect.top - y1) * (x2 - x1) / (double)(y2 - y1) + 0.5); } break; case 4: // S { ny1 = rect.bottom; nx1 = int(x1 + (rect.bottom - y1) * (x2 - x1) / (double)(y2 - y1) + 0.5); } break; case 1: // W { nx1 = rect.left; ny1 = int(y1 + (rect.left - x1) * (y2 - y1) / (double)(x2 - x1) + 0.5); } break; case 2: // E { nx1 = rect.right; ny1 = int(y1 + (rect.right - x1) * (y2 - y1) / (double)(x2 - x1) + 0.5); } break; case 9: // NW { // 先和求N的一样 ny1 = rect.top; nx1 = int(x1 + (rect.top - y1) * (x2 - x1) / (double)(y2 - y1) + 0.5); // 然后判断结果 if (nx1 < rect.left || nx1 > rect.right) // 上面的假设错误，需要算与左边线的交点 { nx1 = rect.left; ny1 = int(y1 + (rect.left - x1) * (y2 - y1) / (double)(x2 - x1) + 0.5); } } break; case 10: // NE { ny1 = rect.top; nx1 = int(x1 + (rect.top - y1) * (x2 - x1) / (double)(y2 - y1) + 0.5); if (nx1 < rect.left || nx1 > rect.right) { nx1 = rect.right; ny1 = int(y1 + (rect.right - x1) * (y2 - y1) / (double)(x2 - x1) + 0.5); } } break; case 6: // SE { ny1 = rect.bottom; nx1 = int(x1 + (rect.bottom - y1) * (x2 - x1) / (double)(y2 - y1) + 0.5); if (nx1 < rect.left || nx1 > rect.right) { nx1 = rect.right; ny1 = int(y1 + (rect.right - x1) * (y2 - y1) / (double)(x2 - x1) + 0.5); } } break; case 5: // SW { ny1 = rect.bottom; nx1 = int(x1 + (rect.bottom - y1) * (x2 - x1) / (double)(y2 - y1) + 0.5); if (nx1 < rect.left || nx1 > rect.right) { nx1 = rect.left; ny1 = int(y1 + (rect.left - x1) * (y2 - y1) / (double)(x2 - x1) + 0.5); } } break; } // 计算np2的坐标nx2, ny2 switch(p2code) { case 0: // C { nx2 = x2; ny2 = y2; } break; case 8: // N { ny2 = rect.top; nx2 = int(x1 + (rect.top - y1) * (x2 - x1) / (double)(y2 - y1) + 0.5); } break; case 4: // S { ny2 = rect.bottom; nx2 = int(x1 + (rect.bottom - y1) * (x2 - x1) / (double)(y2 - y1) + 0.5); } break; case 1: // W { nx2 = rect.left; ny2 = int(y1 + (rect.left - x1) * (y2 - y1) / (double)(x2 - x1) + 0.5); } break; case 2: // E { nx2 = rect.right; ny2 = int(y1 + (rect.right - x1) * (y2 - y1) / (double)(x2 - x1) + 0.5); } break; case 9: // NW { // 先和求N的一样 ny2 = rect.top; nx2 = int(x1 + (rect.top - y1) * (x2 - x1) / (double)(y2 - y1) + 0.5); // 然后判断结果 if (nx2 < rect.left || nx2 > rect.right) // 上面的假设错误，需要算与左边线的交点 { nx2 = rect.left; ny2 = int(y1 + (rect.left - x1) * (y2 - y1) / (double)(x2 - x1) + 0.5); } } break; case 10: // NE { ny2 = rect.top; nx2 = int(x1 + (rect.top - y1) * (x2 - x1) / (double)(y2 - y1) + 0.5); if (nx2 < rect.left || nx2 > rect.right) { nx2 = rect.right; ny2 = int(y1 + (rect.right - x1) * (y2 - y1) / (double)(x2 - x1) + 0.5); } } break; case 6: // SE { ny2 = rect.bottom; nx2 = int(x1 + (rect.bottom - y1) * (x2 - x1) / (double)(y2 - y1) + 0.5); if (nx2 < rect.left || nx2 > rect.right) { nx2 = rect.right; ny2 = int(y1 + (rect.right - x1) * (y2 - y1) / (double)(x2 - x1) + 0.5); } } break; case 5: // SW { ny2 = rect.bottom; nx2 = int(x1 + (rect.bottom - y1) * (x2 - x1) / (double)(y2 - y1) + 0.5); if (nx2 < rect.left || nx2 > rect.right) { nx2 = rect.left; ny2 = int(y1 + (rect.left - x1) * (y2 - y1) / (double)(x2 - x1) + 0.5); } } break; } // 过滤一种直线与矩形不相交的特殊情况 if (nx1 < rect.left || nx1 > rect.right || ny1 < rect.top || ny1 > rect.bottom || nx2 < rect.left || nx2 > rect.right || ny2 < rect.top || ny2 > rect.bottom) { return 0; } return 1; } void _CPPYIN_3DLib::FlipSurface() { // 获取后台缓存 IDirect3DSurface9* backBuffer = 0; pDevice->GetBackBuffer(0, 0, D3DBACKBUFFER_TYPE_MONO, &backBuffer); // 使用自定义表面填充后台缓存 pDevice->StretchRect(pSurface, 0, backBuffer, 0, D3DTEXF_NONE); // GetBackBuffer所得的缓存需要被释放，否则会内存泄露 backBuffer->Release(); // 将交换链中的后台缓存显示 pDevice->Present(0, 0, 0, 0); } void _CPPYIN_3DLib::Release3DLib() { pSurface->Release(); pDevice->Release(); }