1
| | #pragma comment(lib, "glu32.lib")
#define WIN32_LEAN_AND_MEAN // trim the excess fat from Windows
////// Defines
#define BITMAP_ID 0x4D42 // the universal bitmap ID
#define MAP_X 32 // size of map along x-axis
#define MAP_Z 32 // size of map along z-axis
#define MAP_SCALE 20.0f // the scale of the terrain map
#define PI 3.14159
////// Includes
#include <windows.h> // standard Windows app include
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <gl/gl.h> // standard OpenGL include
#include <gl/glu.h> // OpenGL utilties
////// Global Variables
HDC g_HDC; // global device context
bool fullScreen = false; // true = fullscreen; false = windowed
bool keyPressed[256]; // holds true for keys that are pressed
float angle = 0.0f; // camera angle
float radians = 0.0f; // camera angle in radians
float waterHeight = 154.0f; // height of water
bool waterDir = true; // used to animate water; true = up, false = down
////// Mouse/Camera Variables
int mouseX, mouseY; // mouse coordinates
float cameraX, cameraY, cameraZ; // camera coordinates
float lookX, lookY, lookZ; // camera look-at coordinates
////// Texture Information
BITMAPINFOHEADER bitmapInfoHeader; // temp bitmap info header
BITMAPINFOHEADER landInfo; // land texture info header
BITMAPINFOHEADER waterInfo; // water texture info header
unsigned char* imageData; // the map image data
unsigned char* landTexture; // land texture data
unsigned char* waterTexture; // water texture data
unsigned int land; // the land texture object
unsigned int water; // the water texture object
////// Terrain Data
float terrain[MAP_X][MAP_Z][3]; // heightfield terrain data (0-255); 256x256
// LoadBitmapFile
// desc: Returns a pointer to the bitmap image of the bitmap specified
// by filename. Also returns the bitmap header information.
// No support for 8-bit bitmaps.
unsigned char *LoadBitmapFile(char *filename, BITMAPINFOHEADER *bitmapInfoHeader)
{
FILE *filePtr; // the file pointer
BITMAPFILEHEADER bitmapFileHeader; // bitmap file header
unsigned char *bitmapImage; // bitmap image data
int imageIdx = 0; // image index counter
unsigned char tempRGB; // swap variable
// open filename in "read binary" mode
filePtr = fopen(filename, "rb");
if (filePtr == NULL)
return NULL;
// read the bitmap file header
fread(&bitmapFileHeader, sizeof(BITMAPFILEHEADER), 1, filePtr);
// verify that this is a bitmap by checking for the universal bitmap id
if (bitmapFileHeader.bfType != BITMAP_ID)
{
fclose(filePtr);
return NULL;
}
// read the bitmap information header
fread(bitmapInfoHeader, sizeof(BITMAPINFOHEADER), 1, filePtr);
// move file pointer to beginning of bitmap data
fseek(filePtr, bitmapFileHeader.bfOffBits, SEEK_SET);
// allocate enough memory for the bitmap image data
bitmapImage = (unsigned char*)malloc(bitmapInfoHeader->biSizeImage);
// verify memory allocation
if (!bitmapImage)
{
free(bitmapImage);
fclose(filePtr);
return NULL;
}
// read in the bitmap image data
fread(bitmapImage, 1, bitmapInfoHeader->biSizeImage, filePtr);
// make sure bitmap image data was read
if (bitmapImage == NULL)
{
fclose(filePtr);
return NULL;
}
// swap the R and B values to get RGB since the bitmap color format is in BGR
for (imageIdx = 0; imageIdx < bitmapInfoHeader->biSizeImage; imageIdx+=3)
{
tempRGB = bitmapImage[imageIdx];
bitmapImage[imageIdx] = bitmapImage[imageIdx + 2];
bitmapImage[imageIdx + 2] = tempRGB;
}
// close the file and return the bitmap image data
fclose(filePtr);
return bitmapImage;
}
// InitializeTerrain()
// desc: initializes the heightfield terrain data
void InitializeTerrain()
{
// loop through all of the heightfield points, calculating
// the coordinates for each point
for (int z = 0; z < MAP_Z; z++)
{
for (int x = 0; x < MAP_X; x++)
{
terrain[x][z][0] = float(x)*MAP_SCALE;
terrain[x][z][1] = (float)imageData[(z*MAP_Z+x)*3];
terrain[x][z][2] = -float(z)*MAP_SCALE;
}
}
}
bool LoadTextures()
{
// load the land texture data
landTexture = LoadBitmapFile("green.bmp", &landInfo);
if (!landTexture)
return false;
// load the water texture data
waterTexture = LoadBitmapFile("water.bmp", &waterInfo);
if (!waterTexture)
return false;
// generate the land texture as a mipmap
glGenTextures(1, &land);
glBindTexture(GL_TEXTURE_2D, land);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
gluBuild2DMipmaps(GL_TEXTURE_2D, GL_RGB, landInfo.biWidth, landInfo.biHeight, GL_RGB, GL_UNSIGNED_BYTE, landTexture);
// generate the water texture as a mipmap
glGenTextures(1, &water);
glBindTexture(GL_TEXTURE_2D, water);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
gluBuild2DMipmaps(GL_TEXTURE_2D, GL_RGB, waterInfo.biWidth, waterInfo.biHeight, GL_RGB, GL_UNSIGNED_BYTE, waterTexture);
return true;
}
void CleanUp()
{
free(imageData);
free(landTexture);
free(waterTexture);
}
// Initialize
// desc: initializes OpenGL
void Initialize()
{
glClearColor(0.0f, 0.0f, 0.0f, 0.0f); // clear to black
glShadeModel(GL_SMOOTH); // use smooth shading
glEnable(GL_DEPTH_TEST); // hidden surface removal
glEnable(GL_CULL_FACE); // do not calculate inside of poly's
glFrontFace(GL_CCW); // counter clock-wise polygons are out
glEnable(GL_TEXTURE_2D); // enable 2D texturing
imageData = LoadBitmapFile#t2#5--, &bitmapInfoHeader);
// initialize the terrain data and load the textures
InitializeTerrain();
LoadTextures();
}
// Render
// desc: handles drawing of scene
void Render()
{
radians = float(PI*(angle-90.0f)/180.0f);
// calculate the camera's position
cameraX = lookX + sin(radians)*mouseY; // multiplying by mouseY makes the
cameraZ = lookZ + cos(radians)*mouseY; // camera get closer/farther away with mouseY
cameraY = lookY + mouseY / 2.0f;
// calculate the camera look-at coordinates as the center of the terrain map
lookX = (MAP_X*MAP_SCALE)/2.0f;
lookY = 150.0f;
lookZ = -(MAP_Z*MAP_SCALE)/2.0f;
// clear screen and depth buffer
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glLoadIdentity();
// set the camera position
gluLookAt(cameraX, cameraY, cameraZ, lookX, lookY, lookZ, 0.0, 1.0, 0.0);
// set the current texture to the land texture
glBindTexture(GL_TEXTURE_2D, land);
// we are going to loop through all of our terrain's data points,
// but we only want to draw one triangle strip for each set along the x-axis.
for (int z = 0; z < MAP_Z-1; z++)
{
glBegin(GL_TRIANGLE_STRIP);
//glBegin(GL_POINTS);
for (int x = 0; x < MAP_X-1; x++)
{
// for each vertex, we calculate the grayscale shade color,
// we set the texture coordinate, and we draw the vertex.
/*
the vertices are drawn in this order:
0 ---> 1
/
/
|/
2 ---> 3
*/
// draw vertex 0
glColor3f(terrain[x][z][1]/255.0f, terrain[x][z][1]/255.0f, terrain[x][z][1]/255.0f);
glTexCoord2f(0.0f, 0.0f);
glVertex3f(terrain[x][z][0], terrain[x][z][1], terrain[x][z][2]);
// draw vertex 1
glTexCoord2f(1.0f, 0.0f);
glColor3f(terrain[x+1][z][1]/255.0f, terrain[x+1][z][1]/255.0f, terrain[x+1][z][1]/255.0f);
glVertex3f(terrain[x+1][z][0], terrain[x+1][z][1], terrain[x+1][z][2]);
// draw vertex 2
glTexCoord2f(0.0f, 1.0f);
glColor3f(terrain[x][z+1][1]/255.0f, terrain[x][z+1][1]/255.0f, terrain[x][z+1][1]/255.0f);
glVertex3f(terrain[x][z+1][0], terrain[x][z+1][1], terrain[x][z+1][2]);
// draw vertex 3
glColor3f(terrain[x+1][z+1][1]/255.0f, terrain[x+1][z+1][1]/255.0f, terrain[x+1][z+1][1]/255.0f);
glTexCoord2f(1.0f, 1.0f);
glVertex3f(terrain[x+1][z+1][0], terrain[x+1][z+1][1], terrain[x+1][z+1][2]);
}
glEnd();
}
// enable blending
glEnable(GL_BLEND);
// enable read-only depth buffer
glDepthMask(GL_FALSE);
// set the blend function to what we use for transparency
glBlendFunc(GL_SRC_ALPHA, GL_ONE);
glColor4f(0.5f, 0.5f, 1.0f, 0.7f); // set color to a transparent blue
glBindTexture(GL_TEXTURE_2D, water); // set texture to the water texture
// draw water as one large quad surface
glBegin(GL_QUADS);
glTexCoord2f(0.0f, 0.0f); // lower left corner
glVertex3f(terrain[0][0][0], waterHeight, terrain[0][0][2]);
glTexCoord2f(10.0f, 0.0f); // lower right corner
glVertex3f(terrain[MAP_X-1][0][0], waterHeight, terrain[MAP_X-1][0][2]);
glTexCoord2f(10.0f, 10.0f); // upper right corner
glVertex3f(terrain[MAP_X-1][MAP_Z-1][0], waterHeight, terrain[MAP_X-1][MAP_Z-1][2]);
glTexCoord2f(0.0f, 10.0f); // upper left corner
glVertex3f(terrain[0][MAP_Z-1][0],waterHeight, terrain[0][MAP_Z-1][2]);
glEnd();
// set back to normal depth buffer mode (writable)
glDepthMask(GL_TRUE);
// disable blending
glDisable(GL_BLEND);
// animate the water
if (waterHeight > 155.0f)
waterDir = false;
else if (waterHeight < 154.0f)
waterDir = true;
if (waterDir)
waterHeight += 0.01f;
else
waterHeight -= 0.01f;
glFlush();
SwapBuffers(g_HDC); // bring backbuffer to foreground
}
// function to set the pixel format for the device context
void SetupPixelFormat(HDC hDC)
{
int nPixelFormat; // our pixel format index
static PIXELFORMATDESCRIPTOR pfd = {
sizeof(PIXELFORMATDESCRIPTOR), // size of structure
1, // default version
PFD_DRAW_TO_WINDOW | // window drawing support
PFD_SUPPORT_OPENGL | // OpenGL support
PFD_DOUBLEBUFFER, // double buffering support
PFD_TYPE_RGBA, // RGBA color mode
32, // 32 bit color mode
0, 0, 0, 0, 0, 0, // ignore color bits, non-palettized mode
0, // no alpha buffer
0, // ignore shift bit
0, // no accumulation buffer
0, 0, 0, 0, // ignore accumulation bits
16, // 16 bit z-buffer size
0, // no stencil buffer
0, // no auxiliary buffer
PFD_MAIN_PLANE, // main drawing plane
0, // reserved
0, 0, 0 }; // layer masks ignored
nPixelFormat = ChoosePixelFormat(hDC, &pfd); // choose best matching pixel format
SetPixelFormat(hDC, nPixelFormat, &pfd); // set pixel format to device context
}
// the Windows Procedure event handler
LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
static HGLRC hRC; // rendering context
static HDC hDC; // device context
int width, height; // window width and height
int oldMouseX, oldMouseY;
switch(message)
{
case WM_CREATE: // window is being created
hDC = GetDC(hwnd); // get current window's device context
g_HDC = hDC;
SetupPixelFormat(hDC); // call our pixel format setup function
// create rendering context and make it current
hRC = wglCreateContext(hDC);
wglMakeCurrent(hDC, hRC);
return 0;
break;
case WM_CLOSE: // windows is closing
// deselect rendering context and delete it
wglMakeCurrent(hDC, NULL);
wglDeleteContext(hRC);
// send WM_QUIT to message queue
PostQuitMessage(0);
return 0;
break;
case WM_SIZE:
height = HIWORD(lParam); // retrieve width and height
width = LOWORD(lParam);
if (height==0) // don't want a divide by zero
{
height=1;
}
glViewport(0, 0, width, height); // reset the viewport to new dimensions
glMatrixMode(GL_PROJECTION); // set projection matrix current matrix
glLoadIdentity(); // reset projection matrix
// calculate aspect ratio of window
gluPerspective(54.0f,(GLfloat)width/(GLfloat)height,1.0f,1000.0f);
glMatrixMode(GL_MODELVIEW); // set modelview matrix
glLoadIdentity(); // reset modelview matrix
return 0;
break;
case WM_KEYDOWN: // is a key pressed?
keyPressed[wParam] = true;
return 0;
break;
case WM_KEYUP:
keyPressed[wParam] = false;
return 0;
break;
case WM_MOUSEMOVE:
// save old mouse coordinates
oldMouseX = mouseX;
oldMouseY = mouseY;
// get mouse coordinates from Windows
mouseX = LOWORD(lParam);
mouseY = HIWORD(lParam);
// these lines limit the camera's range
if (mouseY < 200)
mouseY = 200;
if (mouseY > 450)
mouseY = 450;
if ((mouseX - oldMouseX) > 0) // mouse moved to the right
angle += 3.0f;
else if ((mouseX - oldMouseX) < 0) // mouse moved to the left
angle -= 3.0f;
return 0;
break;
default:
break;
}
return (DefWindowProc(hwnd, message, wParam, lParam));
}
// the main windows entry point
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nShowCmd)
{
WNDCLASSEX windowClass; // window class
HWND hwnd; // window handle
MSG msg; // message
bool done; // flag saying when our app is complete
DWORD dwExStyle; // Window Extended Style
DWORD dwStyle; // Window Style
RECT windowRect;
// temp var's
int width = 800;
int height = 600;
int bits = 32;
//fullScreen = TRUE;
windowRect.left=(long)0; // Set Left Value To 0
windowRect.right=(long)width; // Set Right Value To Requested Width
windowRect.top=(long)0; // Set Top Value To 0
windowRect.bottom=(long)height; // Set Bottom Value To Requested Height
// fill out the window class structure
windowClass.cbSize = sizeof(WNDCLASSEX);
windowClass.style = CS_HREDRAW | CS_VREDRAW;
windowClass.lpfnWndProc = WndProc;
windowClass.cbClsExtra = 0;
windowClass.cbWndExtra = 0;
windowClass.hInstance = hInstance;
windowClass.hIcon = LoadIcon(NULL, IDI_APPLICATION); // default icon
windowClass.hCursor = LoadCursor(NULL, IDC_ARROW); // default arrow
windowClass.hbrBackground = NULL; // don't need background
windowClass.lpszMenuName = NULL; // no menu
windowClass.lpszClassName = "MyClass";
windowClass.hIconSm = LoadIcon(NULL, IDI_WINLOGO); // windows logo small icon
// register the windows class
if (!RegisterClassEx(&windowClass))
return 0;
if (fullScreen) // fullscreen?
{
DEVMODE dmScreenSettings; // device mode
memset(&dmScreenSettings,0,sizeof(dmScreenSettings));
dmScreenSettings.dmSize = sizeof(dmScreenSettings);
dmScreenSettings.dmPelsWidth = width; // screen width
dmScreenSettings.dmPelsHeight = height; // screen height
dmScreenSettings.dmBitsPerPel = bits; // bits per pixel
dmScreenSettings.dmFields=DM_BITSPERPEL|DM_PELSWIDTH|DM_PELSHEIGHT;
//
if (ChangeDisplaySettings(&dmScreenSettings, CDS_FULLSCREEN) != DISP_CHANGE_SUCCESSFUL)
{
// setting display mode failed, switch to windowed
MessageBox(NULL, "Display mode failed", NULL, MB_OK);
fullScreen=FALSE;
}
}
if (fullScreen) // Are We Still In Fullscreen Mode?
{
dwExStyle=WS_EX_APPWINDOW; // Window Extended Style
dwStyle=WS_POPUP; // Windows Style
ShowCursor(FALSE); // Hide Mouse Pointer
}
else
{
dwExStyle=WS_EX_APPWINDOW | WS_EX_WINDOWEDGE; // Window Extended Style
dwStyle=WS_OVERLAPPEDWINDOW; // Windows Style
}
AdjustWindowRectEx(&windowRect, dwStyle, FALSE, dwExStyle); // Adjust Window To True Requested Size
// class registered, so now create our window
hwnd = CreateWindowEx(NULL, // extended style
"MyClass", // class name
"Texture Example 3: The Heightfield Terrain Example", // app name
dwStyle | WS_CLIPCHILDREN |
WS_CLIPSIBLINGS,
0, 0, // x,y coordinate
windowRect.right - windowRect.left,
windowRect.bottom - windowRect.top, // width, height
NULL, // handle to parent
NULL, // handle to menu
hInstance, // application instance
NULL); // no extra params
// check if window creation failed (hwnd would equal NULL)
if (!hwnd)
return 0;
ShowWindow(hwnd, SW_SHOW); // display the window
UpdateWindow(hwnd); // update the window
done = false; // intialize the loop condition variable
Initialize(); // initialize OpenGL
// main message loop
while (!done)
{
PeekMessage(&msg, hwnd, NULL, NULL, PM_REMOVE);
if (msg.message == WM_QUIT) // do we receive a WM_QUIT message?
{
done = true; // if so, time to quit the application
}
else
{
if (keyPressed[VK_ESCAPE])
done = true;
else
{
Render();
TranslateMessage(&msg); // translate and dispatch to event queue
DispatchMessage(&msg);
}
}
}
CleanUp();
if (fullScreen)
{
ChangeDisplaySettings(NULL,0); // If So Switch Back To The Desktop
ShowCursor(TRUE); // Show Mouse Pointer
}
return msg.wParam;
} |
