UINT msg,

WPARAM wparam,

LPARAM lparam)

{

// this is the main message handler of the system

PAINTSTRUCT ps; // used in WM_PAINT

HDC hdc; // handle to a device context

char buffer[80]; // used to print strings

// what is the message

switch(msg)

{

case WM_CREATE:

{

// do initialization stuff here

// return success

return(0);

} break;

case WM_PAINT:

{

// simply validate the window

hdc = BeginPaint(hwnd,&ps);

// end painting

EndPaint(hwnd,&ps);

// return success

return(0);

} break;

case WM_DESTROY:

{

// kill the application, this sends a WM_QUIT message

PostQuitMessage(0);

// return success

return(0);

} break;

default:break;

} // end switch

// process any messages that we didn't take care of

return (DefWindowProc(hwnd, msg, wparam, lparam));

HINSTANCE hprevinstance,

LPSTR lpcmdline,

int ncmdshow)

{

WNDCLASSEX winclass; // this will hold the class we create

HWND hwnd; // generic window handle

MSG msg; // generic message

HDC hdc; // graphics device context

// first fill in the window class stucture

winclass.cbSize = sizeof(WNDCLASSEX);

winclass.style = CS_DBLCLKS | CS_OWNDC |

CS_HREDRAW | CS_VREDRAW;

winclass.lpfnWndProc = WindowProc;

winclass.cbClsExtra = 0;

winclass.cbWndExtra = 0;

winclass.hInstance = hinstance;

winclass.hIcon = LoadIcon(NULL, IDI_APPLICATION);

winclass.hCursor = LoadCursor(NULL, IDC_ARROW);

winclass.hbrBackground = (HBRUSH)GetStockObject(BLACK_BRUSH);

winclass.lpszMenuName = NULL;

winclass.lpszClassName = WINDOW_CLASS_NAME;

winclass.hIconSm = LoadIcon(NULL, IDI_APPLICATION);

// save hinstance in global

main_instance = hinstance;

// register the window class

if (!RegisterClassEx(&winclass))

return(0);

// create the window

if (!(hwnd = CreateWindowEx(NULL, // extended style

WINDOW_CLASS_NAME, // class

"DirectDraw 8-Bit Smooth Scrolling Demo", // title

WS_POPUP | WS_VISIBLE,

0,0, // initial x,y

SCREEN_WIDTH,SCREEN_HEIGHT, // initial width, height

NULL, // handle to parent

NULL, // handle to menu

hinstance,// instance of this application

NULL))) // extra creation parms

return(0);

// save main window handle

main_window_handle = hwnd;

// initialize game here

Game_Init();

// enter main event loop

while(TRUE)

{

// test if there is a message in queue, if so get it

if (PeekMessage(&msg,NULL,0,0,PM_REMOVE))

{

// test if this is a quit

if (msg.message == WM_QUIT)

break;

// translate any accelerator keys

TranslateMessage(&msg);

// send the message to the window proc

DispatchMessage(&msg);

} // end if

// main game processing goes here

Game_Main();

} // end while

// closedown game here

Game_Shutdown();

// return to Windows like this

return(msg.wParam);

{

// this function is where you do all the initialization

// for your game

int index; // looping var

char filename[80]; // used to build up files names

// initialize directdraw

DDraw_Init(SCREEN_WIDTH, SCREEN_HEIGHT, SCREEN_BPP);

// load in texture maps

Load_Bitmap_File(&bitmap8bit, "SCROLLTEXTURES.BMP");

// set the palette to background image palette

Set_Palette(bitmap8bit.palette);

// create the texture bob

if (!Create_BOB(&textures,0,0,64,64,10,

BOB_ATTR_VISIBLE | BOB_ATTR_MULTI_FRAME,DDSCAPS_SYSTEMMEMORY))

return(0);

// load each texture bitmap into the texture BOB object

for (index = 0; index < NUM_TEXTURES; index++)

Load_Frame_BOB(&textures,&bitmap8bit,index,index%4,index/4,BITMAP_EXTRACT_MODE_CELL);

// unload the texture map bitmap

Unload_Bitmap_File(&bitmap8bit);

// set clipping rectangle to screen extents so mouse cursor

// doens't mess up at edges

RECT screen_rect = {0,0,screen_width,screen_height-32}; // 32 pixels at the bottom for controls

// notice at bottom of screen a blank rect, this would be for your

// control panel for example

lpddclipper = DDraw_Attach_Clipper(lpddsback,1,&screen_rect);

// hide the mouse

ShowCursor(FALSE);

// return success

return(1);

{

// this function is where you shutdown your game and

// release all resources that you allocated

// kill texture memory

Destroy_BOB(&textures);

// shutdonw directdraw

DDraw_Shutdown();

// return success

return(1);

{

// this is the workhorse of your game it will be called

// continuously in real-time this is like main() in C

// all the calls for you game go here!

int index, index_x, index_y; // looping vars

int start_map_x,start_map_y, // map positions

end_map_x,end_map_y;

int offset_x, offset_y; // pixel offsets within cell

// check of user is trying to exit

if (KEY_DOWN(VK_ESCAPE) || KEY_DOWN(VK_SPACE))

PostMessage(main_window_handle, WM_DESTROY,0,0);

// start the timing clock

Start_Clock();

// clear the drawing surface

DDraw_Fill_Surface(lpddsback, 0);

// check for movement (scrolling)

if (KEY_DOWN(VK_RIGHT))

{

if ((world_x+=4) >= 1280)

world_x = 1279;

} // end if

else

if (KEY_DOWN(VK_LEFT))

{

if ((world_x-=4) < 0)

world_x = 0;

} // end if

if (KEY_DOWN(VK_UP))

{

if ((world_y-=4) < 0)

world_y = 0;

} // end if

else

if (KEY_DOWN(VK_DOWN))

{

if ((world_y+=4) >= 896)

world_y = 895;

} // end if

// compute starting map indices by dividing position by size of cell

start_map_x = world_x/64; // use >> 6 for speed, but this is clearer

start_map_y = world_y/64;

// compute end of map rectangle for best cast i.e. aligned on 64x64 boundary

end_map_x = start_map_x + 10 - 1;

end_map_y = start_map_y + 7 - 1;

// now compute number of pixels in x,y we are within the tile, i.e

// how much is scrolled off the edge?

offset_x = -(world_x % 64);

offset_y = -(world_y % 64);

// adjust end_map_x,y for offsets

if (offset_x)

end_map_x++;

if (offset_y)

end_map_y++;

// set starting position of first upper lh texture

int texture_x = offset_x;

int texture_y = offset_y;

// draw the current window

for (index_y = start_map_y; index_y <= end_map_y; index_y++)

{

for (index_x = start_map_x; index_x <= end_map_x; index_x++)

{

// set position to blit

textures.x = texture_x;

textures.y = texture_y;

// set frame

textures.curr_frame = world[index_y][index_x] - '0';

// draw the texture

Draw_BOB(&textures,lpddsback);

// update texture position

texture_x+=64;

} // end for map_x

// reset x postion, update y

texture_x = offset_x;

texture_y += 64;

} // end for map_y

// draw some info

Draw_Text_GDI("USE ARROW KEYS TO MOVE, <ESC> to Exit.",8,8,RGB(255,255,255),lpddsback);

sprintf(buffer,"World Position = [%d, %d] ", world_x, world_y);

Draw_Text_GDI(buffer,8,screen_height - 32 - 24,RGB(0,255,0),lpddsback);

// flip the surfaces

DDraw_Flip();

// sync to 30 fps

Wait_Clock(30);

// return success

return(1);