Lesson 7 Nehe

#include <gl/opengl.h>
#include <stdio.h>

HGLRC hRC = NULL;
HDC   hDC = NULL;
HWND  hWnd = NULL;
HINSTANCE hInstance = NULL;

BOOL keys[256];
BOOL active = TRUE;
BOOL fullscreen = FALSE;

BOOL light = TRUE;              // 光源开关
BOOL lp = TRUE;                 // L键按下了吗？
BOOL fp;                        // F键按下了吗？

GLfloat xRote;
GLfloat yRote;
GLfloat xStep = 0.1f;                   // X旋转速度
GLfloat yStep = 0.1f;                   // Y 旋转速度
GLfloat z = -5.0f;              // 深入屏幕的距离

GLfloat LightAmbient[]  = {0.5f, 0.5f, 0.5f, 1.0f};  //环境光参数
GLfloat LightDiffuse[]  = {1.0f, 1.0f, 1.0f, 1.0f};  //漫射光参数数
GLfloat LightPosition[] = {0.0f, 0.0f, 2.0f, 1.0f};  //光源位置
GLuint  filter = 0;                                      // 跟踪采用何种纹理
GLuint texture[3];                                   // 存三个纹理


LRESULT CALLBACK WindowProc( HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam);

AUX_RGBImageRec* LoadBMP(char* FileName){
FILE *File = NULL;
if (!FileName){
MessageBox(NULL, "文件未存在", "错误", MB_OK|MB_ICONEXCLAMATION);
return NULL;
    }

File = fopen(FileName, "r");
if (!File){
MessageBox(NULL, "文件未能正常打开", "错误", MB_OK|MB_ICONEXCLAMATION);
return  NULL;
    }
fclose(File);
return auxDIBImageLoad(FileName);
}

BOOL LoadGLTexture(char* Filename, GLuint* texture){
BOOL Status  =  FALSE;
AUX_RGBImageRec *TextureImage[1];
memset(TextureImage, 0, sizeof(void*)*1);
if (TextureImage[0] = LoadBMP(Filename)){
Status = TRUE;
// 创建三个纹理
glGenTextures(3, texture);

///////////////////////////////////////////////////
glBindTexture(GL_TEXTURE_2D, texture[0]);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexImage2D(GL_TEXTURE_2D,  0, 3, TextureImage[0]->sizeX, TextureImage[0]->sizeY, 0, GL_RGB, GL_UNSIGNED_BYTE, TextureImage[0]->data);

////////////////////////////////////////////////////////
glBindTexture(GL_TEXTURE_2D, texture[1]);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexImage2D(GL_TEXTURE_2D,  0, 3, TextureImage[0]->sizeX, TextureImage[0]->sizeY, 0, GL_RGB, GL_UNSIGNED_BYTE, TextureImage[0]->data);

////////////////////////////////////////////////////////
glBindTexture(GL_TEXTURE_2D, texture[2]);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
gluBuild2DMipmaps(GL_TEXTURE_2D, 3, TextureImage[0]->sizeX, TextureImage[0]->sizeY, GL_RGB, GL_UNSIGNED_BYTE, TextureImage[0]->data);
    }
if (TextureImage[0]){
if (TextureImage[0]->data)
free(TextureImage[0]->data);
free(TextureImage[0]);
    }
return Status;
}
GLvoid ReSizeGLScene(GLsizei width, GLsizei height){
// 如果高为0 ， 则设置其为1
if (height == 0) height = 1;
// 设置可以看到的视角
glViewport(0,0,width, height);

// 设置投影矩阵
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
// 设置平截头体
gluPerspective(45.0f, (GLdouble)width/(GLdouble)height, 0.1f, 100.0f);

// 设置模型矩阵
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
}

GLvoid InitGL(){
if (!LoadGLTexture("Data/Nehe.bmp", &texture[0])){
MessageBox(NULL, "载入纹理失败", "错误", MB_OK|MB_ICONEXCLAMATION);
exit(1);
    }

// 开启光照
glLightfv(GL_LIGHT1, GL_AMBIENT, LightAmbient); // 设置环境光
glLightfv(GL_LIGHT1, GL_DIFFUSE, LightDiffuse); // 设置漫射光
glLightfv(GL_LIGHT1, GL_POSITION, LightPosition); // 光源位置
glEnable(GL_LIGHT1);
//glEnable(GL_LIGHTING);

glEnable(GL_TEXTURE_2D);
glShadeModel(GL_SMOOTH);
glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
// 1.0f 为最大深度
glClearDepth(1.0f);
glEnable(GL_DEPTH_TEST);
glDepthFunc(GL_LEQUAL);
glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);
}

GLvoid DrawGLScene(){

glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glLoadIdentity();                   // 重置坐标系
glTranslatef(0.0f, 0.0f, z);

glRotatef(xRote, 1.0f, 0.0f, 0.0f);
glRotatef(yRote, 0.0f, 1.0f, 0.0f);

glBindTexture(GL_TEXTURE_2D, texture[filter]);
// 画正方体
glBegin(GL_QUADS);
// 前面
glNormal3f(0.0f, 0.0f, 1.0f);
glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f,-1.0f, 1.0f); // A
glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f, 1.0f, 1.0f); // B
glTexCoord2f(1.0f, 1.0f); glVertex3f( 1.0f, 1.0f, 1.0f); // C
glTexCoord2f(1.0f, 0.0f); glVertex3f( 1.0f,-1.0f, 1.0f); // D

// 右面
glNormal3f(1.0f, 0.0f, 0.0f);
glTexCoord2f(0.0f, 0.0f); glVertex3f( 1.0f,-1.0f, 1.0f); // D
glTexCoord2f(0.0f, 1.0f); glVertex3f( 1.0f, 1.0f, 1.0f); // C
glTexCoord2f(1.0f, 1.0f); glVertex3f( 1.0f, 1.0f,-1.0f); // E
glTexCoord2f(1.0f, 0.0f); glVertex3f( 1.0f,-1.0f,-1.0f); // F

//后面
glNormal3f(0.0f, 0.0f,-1.0f);
glTexCoord2f(0.0f, 0.0f); glVertex3f( 1.0f,-1.0f,-1.0f); // F
glTexCoord2f(0.0f, 1.0f); glVertex3f( 1.0f, 1.0f,-1.0f); // E
glTexCoord2f(1.0f, 1.0f); glVertex3f(-1.0f, 1.0f,-1.0f); // G
glTexCoord2f(1.0f, 0.0f); glVertex3f(-1.0f,-1.0f,-1.0f); // H

//左面
glNormal3f(-1.0f, 0.0f, 0.0f);
glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f,-1.0f,-1.0f); // H
glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f, 1.0f,-1.0f); // G
glTexCoord2f(1.0f, 1.0f); glVertex3f(-1.0f, 1.0f, 1.0f); // B
glTexCoord2f(1.0f, 0.0f); glVertex3f(-1.0f,-1.0f, 1.0f); // A

//上面
glNormal3f(0.0f, 1.0f, 0.0f);
glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f, 1.0f, 1.0f); // B
glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f, 1.0f,-1.0f); // G
glTexCoord2f(1.0f, 1.0f); glVertex3f( 1.0f, 1.0f,-1.0f); // E
glTexCoord2f(1.0f, 0.0f); glVertex3f( 1.0f, 1.0f, 1.0f); // C 

//下面
glNormal3f(0.0f,-1.0f, 0.0f);
glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f,-1.0f,-1.0f); // H
glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f,-1.0f, 1.0f); // A
glTexCoord2f(1.0f, 1.0f); glVertex3f( 1.0f,-1.0f, 1.0f); // D
glTexCoord2f(1.0f, 0.0f); glVertex3f( 1.0f,-1.0f,-1.0f); // F

glEnd();

if (xRote>= 360.0f) xRote = 0.0f;
if (yRote>= 360.0f) yRote = 0.0f;

xRote += xStep;
yRote += yStep;
}

GLvoid KillGLWindow(){
if (fullscreen){
ChangeDisplaySettings(NULL, 0);
ShowCursor(FALSE);
    }

if (hRC){
if (!wglMakeCurrent(NULL, NULL))
MessageBox(NULL, "释放DC 或 RC 失败", "错误", MB_OK);
if (!wglDeleteContext(hRC))
MessageBox(NULL, "释放RC失败", "错误", MB_OK);
hRC = NULL;
    }

// ReleaseDC 失败返回0， 成功返回非0
if (hDC && !ReleaseDC(hWnd, hDC)){
MessageBox(NULL, "释放DC失败", "错误", MB_OK);
hDC = NULL;
    }

if (hWnd && !DestroyWindow(hWnd)){
MessageBox(NULL, "销毁窗口失败", "错误", MB_OK);
hWnd = NULL;
    }

if (!UnregisterClass("opengl", hInstance)){
MessageBox(NULL, "反注册失败", "错误", MB_OK);
hInstance = NULL;
    }
}

bool CreateGLWindow(char* title, int width, int height, int bits, HINSTANCE hInstance, bool fullscreenflag){
GLuint PixelFormat;
WNDCLASS wc;
DWORD dwStyle;
DWORD dwExStyle;


RECT WindowRect;
WindowRect.left = (long)0;
WindowRect.right= (long)width;
WindowRect.top  =  (long)0;
WindowRect.bottom = (long)height;


fullscreen = fullscreenflag;

wc.hInstance = hInstance;
wc.cbClsExtra  = 0;
wc.cbWndExtra  = 0;
wc.style       = CS_HREDRAW | CS_VREDRAW | CS_OWNDC;
wc.lpfnWndProc = WindowProc;
wc.hIcon = LoadIcon(NULL, IDI_WINLOGO);
wc.hCursor = LoadCursor(NULL, IDC_ARROW);
wc.hbrBackground = NULL;
wc.lpszClassName = "opengl";
wc.lpszMenuName = NULL;


// 注册窗口类

if (!RegisterClass(&wc)){
MessageBox(NULL, "窗口注册失败", "错误", MB_OK);
return FALSE;
    }

if (fullscreen){
DEVMODE dmScreenSetting;
memset(&dmScreenSetting, 0, sizeof(dmScreenSetting));
dmScreenSetting.dmSize = sizeof(dmScreenSetting);
dmScreenSetting.dmBitsPerPel = bits;
dmScreenSetting.dmPelsHeight = height;
dmScreenSetting.dmPelsWidth = width;
dmScreenSetting.dmFields = DM_BITSPERPEL | DM_PELSHEIGHT | DM_PELSWIDTH;

// 设置显示模式
if  (ChangeDisplaySettings(&dmScreenSetting, CDS_FULLSCREEN)!= DISP_CHANGE_SUCCESSFUL){
if (MessageBox(NULL, "当前显卡不支持全屏操做\n使用窗口模式?", "错误", MB_YESNO|MB_ICONEXCLAMATION) == IDYES){
fullscreen = FALSE;
            }
else{
MessageBox(NULL, "程序将会被关闭", "错误", MB_OK|MB_ICONEXCLAMATION);
return false;
            }
        }
    }

if (fullscreen){
dwExStyle = WS_EX_APPWINDOW;
dwStyle = WS_POPUP;
ShowCursor(FALSE);
    }
else{
dwExStyle = WS_EX_APPWINDOW | WS_EX_WINDOWEDGE;
dwStyle = WS_OVERLAPPEDWINDOW;
//ShowCursor(TRUE);
    }

dwStyle = dwStyle | WS_CLIPCHILDREN|WS_CLIPSIBLINGS;
AdjustWindowRectEx(&WindowRect, dwStyle, FALSE, dwExStyle);

if (!(hWnd = CreateWindowEx(dwExStyle, "opengl", title, dwStyle, 0,0, WindowRect.right-WindowRect.left, WindowRect.bottom-WindowRect.top, NULL, NULL, hInstance, NULL))){
KillGLWindow();
MessageBox(NULL, "不能创建一个窗口设备描述表", "错误", MB_OK);
return false;
    }

static PIXELFORMATDESCRIPTOR pfd = {
sizeof(PIXELFORMATDESCRIPTOR),
1,
PFD_DRAW_TO_WINDOW|
PFD_SUPPORT_OPENGL|
PFD_DOUBLEBUFFER,
PFD_TYPE_RGBA,
bits,
0, 0, 0, 0, 0, 0,               // 忽略的色彩位
0,                              // 无Alpha缓存
0,                              // 忽略Shift Bit
0,                              // 无累加缓存
0, 0, 0, 0,                     // 忽略聚集位
16,                             // 16位 Z-缓存 (深度缓存)
0,                              // 无蒙板缓存
0,                              // 无辅助缓存
PFD_MAIN_PLANE,                 // 主绘图层
0,                              // Reserved
0, 0, 0                         // 忽略层遮罩
    };
if (!(hDC = GetDC(hWnd))){
KillGLWindow();
MessageBox(NULL, "不能创建一个相匹配的像素模式", "错误", MB_OK|MB_ICONEXCLAMATION);
return false;
    }

if (!(PixelFormat = ChoosePixelFormat(hDC, &pfd))){
KillGLWindow();
MessageBox(NULL, "不能设置像素格式", "错误", MB_OK|MB_ICONEXCLAMATION);
return false;
    }

if (!SetPixelFormat(hDC, PixelFormat, &pfd)){
KillGLWindow();
MessageBox(NULL, "不能设置像素格式", "错误",MB_OK|MB_ICONEXCLAMATION);
return false;
    }

if (!(hRC = wglCreateContext(hDC))){
KillGLWindow();
MessageBox(NULL, "不能创建当前的opengl渲染描述表", "错误", MB_OK|MB_ICONEXCLAMATION);
return false;
    }

if (!wglMakeCurrent(hDC, hRC)){
KillGLWindow();
MessageBox(NULL, "不能激活当前的opengl渲染描述表", "错误", MB_OK);
return false;
    }

ShowWindow(hWnd, SW_SHOW);
// 激活窗口
SetForegroundWindow(hWnd);
// 接收键盘信息
SetFocus(hWnd);
ReSizeGLScene(width, height);

InitGL();
return true;
}

LRESULT CALLBACK WindowProc( HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam ){
switch(uMsg){
case WM_ACTIVATE:
        {
if (!HIWORD(wParam))
active = TRUE;
else
active = FALSE;
return 0;
        }
case WM_CLOSE:
        {
PostQuitMessage(0);
return 0;
        }
case WM_KEYUP:
        {
keys[wParam] = FALSE;
return 0;
        }
case WM_KEYDOWN:
        {
keys[wParam] = TRUE;
return 0;
        }
case WM_SIZE:
        {
ReSizeGLScene(LOWORD(lParam), HIWORD(lParam));
return 0;
        }
    }
return DefWindowProc(hwnd, uMsg, wParam, lParam);
}

int WINAPI WinMain( HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow ){
MSG msg;
BOOL done = FALSE;

if (MessageBox(NULL, "是否在全屏模式下运行?", "提示", MB_YESNO|MB_ICONEXCLAMATION) == IDYES)
fullscreen = TRUE;

if (!CreateGLWindow("Lesson 7", 640, 480, 16, hInstance, fullscreen))
return 0;

while (!done){
if (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE)){
if (msg.message == WM_QUIT)
done = TRUE;
else{
TranslateMessage(&msg);
DispatchMessage(&msg);
            }
        }
else
        {
if (active)
            {
if (keys[VK_ESCAPE])
done = TRUE;
else{
DrawGLScene();
SwapBuffers(hDC);
                }

// 判断L 键按下， 并进行功能
if (keys['L'] && !lp){
lp = TRUE;
if (light)
glEnable(GL_LIGHTING);
else
glDisable(GL_LIGHTING);
light = !light;
                }
if (!keys['L']){
lp = FALSE;
                }

// 判断F键，并进行功能 
if (keys['F'] && fp){
fp = TRUE;
filter++;
if (filter >2) filter = 0;
                }
if (keys['F']){
fp = FALSE;
                }
// PageUp
if (keys[VK_PRIOR]){
z -= 0.05f;
                }
// Page Down
if (keys[VK_NEXT]){
z += 0.05F;
                }
// 上 下 左 右 四个键
if (keys[VK_UP]){
xStep += 0.01f;
                }
if (keys[VK_DOWN])
xStep -= 0.01f;
if (keys[VK_LEFT])
yStep += 0.01f;
if (keys[VK_RIGHT])
yStep -= 0.01f;

// 判断F1
if (keys[VK_F1]){
keys[VK_F1] = FALSE;
KillGLWindow();
fullscreen = !fullscreen;
if (!CreateGLWindow("Lesson 7", 640, 480, 16, hInstance, fullscreen))
return 0;
                }
            }

        }
    }
KillGLWindow();
return (msg.wParam);
}