Using DirectDraw 7
To draw,
first you must create a surface to draw on.
Surfaces
· a surface can be any size
o primary is same as the current screen resolution
o you must have a primary surface
· can be in video or system memory
· all surfaces have the same bit depth &
color space
Create a
primary surface
CreateSurface(<surfaceDesc ptr>, <surface
ptr>, NULL);
Surface descriptor
typedef struct _DDSURFACEDESC2
{ DWORD dwSize; // structure size, you must set
DWORD dwFlags; //valid field flags
DWORD dwHeight; // surface height in
pixels
DWORD dwWidth; // surface width
union
{ LONG
lPitch; // # bytes per row
DWORD dwLinearSize; //unused
}
DWORD dwBackBufferCount; // # of
backBuffers
…
lpVoid lpSurface; // ptr to surface
memory
DDCOLORKEY ddckCKDestBlt; // dest color key
DDCOLORKEY ddckCKSrctBlt; // source color key …
DDSCAPS ddsCaps; // capabilities
structure
} DDSURFACEDESC;
sets which
fiels are valid
|
dwFlag
Value |
Meaning |
|
DDSD_ALL |
all
members valid |
|
DDSD_ALPHABITDEPTH |
|
|
DDSD_BACKBUFFERCOUNT |
|
|
DDSD_CAPS |
|
|
DDSD_CKDESTBLT |
|
|
DDSD_CKDESTOVERLAY |
|
|
DDSD_CKSRCBLT |
|
|
DDSD_CKSRCOVERLAY |
|
|
DDSD_HEIGHT |
|
|
DDSD_LINEARSIZE |
|
|
DDSD_LPSURFACE |
|
|
DDSD_LPSURFACE |
|
|
DDSD_MIPMAPCOUNT |
|
|
DDSD_PITCH |
|
|
DDSD_PIXELFORMAT |
|
|
DDSD_REFRESHRATE |
|
|
DDSD_WIDTH |
|
|
DDSD_ZBUFFERBITDEPTH |
|
typedef
struct _DDSCAPS
{ DWORD
wdCaps; // surface capabilities
} DDSCAPS,
FAR* LPDDSCAPS;
|
DDSCAPS
value |
Meaning |
|
DDSCAPS_BACKBUFFER |
backbuff
in flip chain |
|
DDSCAPS_COMPLEX |
part of
multi surface |
|
DDSCAPS_FLIP |
flippable
surface |
|
DDSCAPS_FRONTBUFFER |
first
(front) buff in flappable |
|
DDSCAPS_MODEX |
modeX =
320X200/240 |
|
DDSCAPS_OFFSCREENPLAIN |
sprite,
bitmap or other offscreen |
|
DDSCAPS_OWNDC |
will hold
DC for a long time |
|
DDSCAPS_PRIMARYSURFACE |
primary
surface |
|
DDSCAPS_STANDARDVGAMODE |
VGA mode
surface |
|
DDSCAPS_SYSTEMMEMORY |
allocated
in sys memory |
Drawing a
pixel at (x,y)
// plot a
pixel on a screen
ddsd.lpSurface[x
+ y*dds.lpPitch] = color; // color index or RGB
Example of
use:
// DEMO6_1.CPP
basic DirectDraw initialization demo
// INCLUDES
///////////////////////////////////////////////
#define WIN32_LEAN_AND_MEAN // just say no to
MFC
#define INITGUID // make sure directX guids are included
#include <windows.h> // include
important windows stuff
#include <windowsx.h>
#include <mmsystem.h>
#include <iostream.h> // include important C/C++ stuff
#include <conio.h>
#include <stdlib.h>
#include <malloc.h>
#include <memory.h>
#include <string.h>
#include <stdarg.h>
#include <stdio.h>
#include <math.h>
#include <io.h>
#include <fcntl.h>
#include <ddraw.h> // include directdraw
// DEFINES
////////////////////////////////////////////////
// defines for
windows
#define WINDOW_CLASS_NAME
"WINCLASS1"
// default
screen size
#define SCREEN_WIDTH 640 // size of screen
#define SCREEN_HEIGHT 480
#define SCREEN_BPP 8
// bits per pixel
#define MAX_COLORS 256
// maximum colors
// TYPES
//////////////////////////////////////////////////////
// basic
unsigned types
typedef unsigned
short USHORT;
typedef unsigned
short WORD;
typedef unsigned
char
UCHAR;
typedef unsigned
char
BYTE;
// MACROS
/////////////////////////////////////////////////
#define KEYDOWN(vk_code)
((GetAsyncKeyState(vk_code) & 0x8000) ? 1 : 0)
#define KEYUP(vk_code) ((GetAsyncKeyState(vk_code) & 0x8000) ?
0 : 1)
// initializes a
direct draw struct
#define
DD_INIT_STRUCT(ddstruct) { memset(&ddstruct,0,sizeof(ddstruct));
ddstruct.dwSize=sizeof(ddstruct); }
// GLOBALS
////////////////////////////////////////////////
HWND main_window_handle = NULL; // globally track main window
HINSTANCE hinstance_app = NULL; //
globally track hinstance
// directdraw
stuff
LPDIRECTDRAW7 lpdd = NULL; // dd object
LPDIRECTDRAWSURFACE7
lpddsprimary = NULL; // dd primary surface
LPDIRECTDRAWSURFACE7
lpddsback = NULL; // dd back surface
LPDIRECTDRAWPALETTE
lpddpal = NULL; // a pointer to
the created dd palette
LPDIRECTDRAWCLIPPER
lpddclipper = NULL; // dd clipper
PALETTEENTRY
palette[256]; // color palette
PALETTEENTRY
save_palette[256]; // used to save palettes
DDSURFACEDESC2
ddsd; // a direct draw surface description
struct
DDBLTFX
ddbltfx; // used to fill
DDSCAPS2
ddscaps; // a direct draw surface capabilities
struct
HRESULT
ddrval; // result back from dd calls
DWORD start_clock_count = 0; // used for timing
// these defined
the general clipping rectangle
int min_clip_x = 0, // clipping rectangle
max_clip_x = SCREEN_WIDTH-1,
min_clip_y = 0,
max_clip_y = SCREEN_HEIGHT-1;
// these are
overwritten globally by DD_Init()
int screen_width = SCREEN_WIDTH, // width
of screen
screen_height = SCREEN_HEIGHT, // height
of screen
screen_bpp = SCREEN_BPP; // bits
per pixel
char buffer[80]; //
general printing buffer
// FUNCTIONS
//////////////////////////////////////////////
LRESULT CALLBACK
WindowProc(HWND hwnd,
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));
} //
end WinProc
///////////////////////////////////////////////////////////
int Game_Main(void *parms = NULL, int
num_parms = 0)
{
// this is the
main loop of the game, do all your processing
// here
// for now test
if user is hitting ESC and send WM_CLOSE
if (KEYDOWN(VK_ESCAPE))
SendMessage(main_window_handle,WM_CLOSE,0,0);
// return
success or failure or your own return code here
return(1);
} //
end Game_Main
////////////////////////////////////////////////////////////
int Game_Init(void *parms = NULL, int
num_parms = 0)
{
// this is
called once after the initial window is created and
// before the
main event loop is entered, do all your initialization
// here
// create
IDirectDraw interface 7.0 object and test for error
if
(FAILED(DirectDrawCreateEx(NULL, (void
**)&lpdd, IID_IDirectDraw7, NULL)))
return(0);
// set
cooperation to normal since this will be a windowed app
lpdd->SetCooperativeLevel(main_window_handle, DDSCL_NORMAL);
// return
success or failure or your own return code here
return(1);
} //
end Game_Init
/////////////////////////////////////////////////////////////
int Game_Shutdown(void *parms = NULL, int
num_parms = 0)
{
// this is
called after the game is exited and the main event
// loop while is
exited, do all you cleanup and shutdown here
// simply blow
away the IDirectDraw4 interface
if (lpdd)
{
lpdd->Release();
lpdd = NULL;
} // end if
// return
success or failure or your own return code here
return(1);
} //
end Game_Shutdown
// WINMAIN
////////////////////////////////////////////////
int WINAPI WinMain( HINSTANCE hinstance,
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
hinstance_app = hinstance;
// register the
window class
if
(!RegisterClassEx(&winclass))
return(0);
// create the
window
if (!(hwnd =
CreateWindowEx(NULL, // extended style
WINDOW_CLASS_NAME, // class
"DirectDraw Initialization Demo", // title
WS_OVERLAPPEDWINDOW | WS_VISIBLE,
0,0, // initial x,y
400,300, // 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);
} //
end WinMain
///////////////////////////////////////////////////////////