Alpha混合

/**************************************************WinMain.cppChapter 6 Alpha Blending DemoProgramming Role-Playing Games with DirectXby Jim Adams (01 Jan 2002)Required libraries: D3D8.LIB**************************************************/// Include files#include #include #include "d3d8.h"// Window handles, class and caption textHWND g_hWnd;HINSTANCE g_hInst;static char g_szClass[] = "AlphaClass";static char g_szCaption[] = "Alpha Blending Demo by Jim Adams";// The Direct3D and Device objectIDirect3D8 *g_pD3D = NULL;IDirect3DDevice8 *g_pD3DDevice = NULL;// The 2-D vertex format and descriptortypedef struct { FLOAT x, y, z; // 2-D coordinates FLOAT rhw; // rhw D3DCOLOR Diffuse; // Diffuse color component} sVertex;#define VERTEXFVF (D3DFVF_XYZRHW | D3DFVF_DIFFUSE)// Vertex bufferIDirect3DVertexBuffer8 *g_pVB = NULL;// Function prototypesint PASCAL WinMain(HINSTANCE hInst, HINSTANCE hPrev, \ LPSTR szCmdLine, int nCmdShow);long FAR PASCAL WindowProc(HWND hWnd, UINT uMsg, \ WPARAM wParam, LPARAM lParam);BOOL DoInit();BOOL DoShutdown();BOOL DoFrame();BOOL SetupMeshes();int PASCAL WinMain(HINSTANCE hInst, HINSTANCE hPrev, \ LPSTR szCmdLine, int nCmdShow){ WNDCLASSEX wcex; MSG Msg; g_hInst = hInst; // Create the window class here and register it wcex.cbSize = sizeof(wcex); wcex.style = CS_CLASSDC; wcex.lpfnWndProc = WindowProc; wcex.cbClsExtra = 0; wcex.cbWndExtra = 0; wcex.hInstance = hInst; wcex.hIcon = LoadIcon(NULL, IDI_APPLICATION); wcex.hCursor = LoadCursor(NULL, IDC_ARROW); wcex.hbrBackground = NULL; wcex.lpszMenuName = NULL; wcex.lpszClassName = g_szClass; wcex.hIconSm = LoadIcon(NULL, IDI_APPLICATION); if(!RegisterClassEx(&wcex)) return FALSE; // Create the Main Window g_hWnd = CreateWindow(g_szClass, g_szCaption, WS_CAPTION | WS_SYSMENU, 0, 0, 400, 400, NULL, NULL, hInst, NULL ); if(!g_hWnd) return FALSE; ShowWindow(g_hWnd, SW_NORMAL); UpdateWindow(g_hWnd); // Run init function and return on error if(DoInit() == FALSE) return FALSE; // Start message pump, waiting for signal to quit ZeroMemory(&Msg, sizeof(MSG)); while(Msg.message != WM_QUIT) { if(PeekMessage(&Msg, NULL, 0, 0, PM_REMOVE)) { TranslateMessage(&Msg); DispatchMessage(&Msg); } if(DoFrame() == FALSE) break; } // Run shutdown function DoShutdown(); UnregisterClass(g_szClass, hInst); return Msg.wParam;}long FAR PASCAL WindowProc(HWND hWnd, UINT uMsg, \ WPARAM wParam, LPARAM lParam){ switch(uMsg) { case WM_DESTROY: PostQuitMessage(0); return 0; } return DefWindowProc(hWnd, uMsg, wParam, lParam);}BOOL DoInit(){ D3DPRESENT_PARAMETERS d3dpp; D3DDISPLAYMODE d3ddm; BYTE *Ptr; sVertex Verts[8] = { { 100.0f, 100.0f, 1.0f, 1.0f, D3DCOLOR_RGBA(0,64,128,255) }, { 300.0f, 100.0f, 1.0f, 1.0f, D3DCOLOR_RGBA(0,64,128,255) }, { 100.0f, 300.0f, 1.0f, 1.0f, D3DCOLOR_RGBA(0,64,128,255) }, { 300.0f, 300.0f, 1.0f, 1.0f, D3DCOLOR_RGBA(0,64,128,255) }, { 50.0f, 150.0f, 1.0f, 1.0f, D3DCOLOR_RGBA(128,0,0,128) }, { 350.0f, 150.0f, 1.0f, 1.0f, D3DCOLOR_RGBA(128,0,0,128) }, { 50.0f, 350.0f, 1.0f, 1.0f, D3DCOLOR_RGBA(128,0,0,128) }, { 350.0f, 350.0f, 1.0f, 1.0f, D3DCOLOR_RGBA(128,0,0,128) } }; // Do a windowed mode initialization of Direct3D if((g_pD3D = Direct3DCreate8(D3D_SDK_VERSION)) == NULL) return FALSE; if(FAILED(g_pD3D->GetAdapterDisplayMode(D3DADAPTER_DEFAULT, &d3ddm))) return FALSE; ZeroMemory(&d3dpp, sizeof(d3dpp)); d3dpp.Windowed = TRUE; d3dpp.SwapEffect = D3DSWAPEFFECT_DISCARD; d3dpp.BackBufferFormat = d3ddm.Format; d3dpp.EnableAutoDepthStencil = FALSE; if(FAILED(g_pD3D->CreateDevice(D3DADAPTER_DEFAULT, D3DDEVTYPE_HAL, g_hWnd, D3DCREATE_SOFTWARE_VERTEXPROCESSING, &d3dpp, &g_pD3DDevice))) return FALSE; // Create the vertex buffer and set data g_pD3DDevice->CreateVertexBuffer(sizeof(sVertex)*8, 0, \ VERTEXFVF, D3DPOOL_DEFAULT, &g_pVB); g_pVB->Lock(0,0, (BYTE**)&Ptr, 0); memcpy(Ptr, Verts, sizeof(Verts)); g_pVB->Unlock(); return TRUE;}BOOL DoShutdown(){ // Release vertex buffer if(g_pVB != NULL) g_pVB->Release(); // Release device and 3D objects if(g_pD3DDevice != NULL) g_pD3DDevice->Release(); if(g_pD3D != NULL) g_pD3D->Release(); return TRUE;}BOOL DoFrame(){ // Clear device backbuffer g_pD3DDevice->Clear(0, NULL, D3DCLEAR_TARGET, \ D3DCOLOR_RGBA(0,0,0,255), 1.0f, 0); // Begin scene if(SUCCEEDED(g_pD3DDevice->BeginScene())) { // Set the vertex stream and shader g_pD3DDevice->SetStreamSource(0, g_pVB, sizeof(sVertex)); g_pD3DDevice->SetVertexShader(VERTEXFVF); // Disable alpha blending and draw 2 polygons g_pD3DDevice->SetRenderState(D3DRS_ALPHABLENDENABLE, FALSE); g_pD3DDevice->DrawPrimitive(D3DPT_TRIANGLESTRIP, 0, 2); // Enable alpha blending and draw 2 polygons g_pD3DDevice->SetRenderState(D3DRS_ALPHABLENDENABLE, TRUE); g_pD3DDevice->SetRenderState(D3DRS_SRCBLEND, D3DBLEND_SRCALPHA); g_pD3DDevice->SetRenderState(D3DRS_DESTBLEND, D3DBLEND_INVSRCALPHA); g_pD3DDevice->DrawPrimitive(D3DPT_TRIANGLESTRIP, 4, 2); // End the scene g_pD3DDevice->EndScene(); } // Display the scene g_pD3DDevice->Present(NULL, NULL, NULL, NULL); return TRUE;}