// DEMO7_11.CPP 16-bit bitmap loading demo

// INCLUDES ///////////////////////////////////////////////

#define WIN32_LEAN_AND_MEAN  // just say no to MFC

#define INITGUID

#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      16   // bits per pixel

#define BITMAP_ID            0x4D42 // universal id for a bitmap
#define MAX_COLORS_PALETTE   256

// TYPES //////////////////////////////////////////////////////

// basic unsigned types
typedef unsigned short USHORT;
typedef unsigned short WORD;
typedef unsigned char  UCHAR;
typedef unsigned char  BYTE;

// container structure for bitmaps .BMP file
typedef struct BITMAP_FILE_TAG
        {
        BITMAPFILEHEADER bitmapfileheader;  // this contains the bitmapfile header
        BITMAPINFOHEADER bitmapinfoheader;  // this is all the info including the palette
        PALETTEENTRY     palette[256];      // we will store the palette here
        UCHAR            *buffer;           // this is a pointer to the data

        } BITMAP_FILE, *BITMAP_FILE_PTR;

// PROTOTYPES  //////////////////////////////////////////////

int Flip_Bitmap(UCHAR *image, int bytes_per_line, int height);

int Load_Bitmap_File(BITMAP_FILE_PTR bitmap, char *filename);

int Unload_Bitmap_File(BITMAP_FILE_PTR bitmap);

// MACROS /////////////////////////////////////////////////

// tests if a key is up or down
#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 DDRAW_INIT_STRUCT(ddstruct) { memset(&ddstruct,0,sizeof(ddstruct)); ddstruct.dwSize=sizeof(ddstruct); }

// this builds a 16 bit color value in 5.5.5 format (1-bit alpha mode)
#define _RGB16BIT555(r,g,b) ((b & 31) + ((g & 31) << 5) + ((r & 31) << 10))

// this builds a 16 bit color value in 5.6.5 format (green dominate mode)
#define _RGB16BIT565(r,g,b) ((b & 31) + ((g & 63) << 5) + ((r & 31) << 11))

// this builds a 32 bit color value in A.8.8.8 format (8-bit alpha mode)
#define _RGB32BIT(a,r,g,b) ((b) + ((g) << 8) + ((r) << 16) + ((a) << 24))

// GLOBALS ////////////////////////////////////////////////

HWND      main_window_handle = NULL; // globally track main window
int       window_closed      = 0;    // tracks if window is closed
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

BITMAP_FILE           bitmap;                // holds the bitmap

char buffer[80];                             // general printing buffer

// FUNCTIONS ////////////////////////////////////////////////

int Load_Bitmap_File(BITMAP_FILE_PTR bitmap, char *filename)
{
// this function opens a bitmap file and loads the data into bitmap

int file_handle,  // the file handle
    index;        // looping index

UCHAR   *temp_buffer = NULL; // used to convert 24 bit images to 16 bit
OFSTRUCT file_data;          // the file data information

// open the file if it exists
if ((file_handle = OpenFile(filename,&file_data,OF_READ))==-1)
   return(0);

// now load the bitmap file header
_lread(file_handle, &bitmap->bitmapfileheader,sizeof(BITMAPFILEHEADER));

// test if this is a bitmap file
if (bitmap->bitmapfileheader.bfType!=BITMAP_ID)
   {
   // close the file
   _lclose(file_handle);

   // return error
   return(0);
   } // end if

// now we know this is a bitmap, so read in all the sections

// first the bitmap infoheader

// now load the bitmap file header
_lread(file_handle, &bitmap->bitmapinfoheader,sizeof(BITMAPINFOHEADER));

// now load the color palette if there is one
if (bitmap->bitmapinfoheader.biBitCount == 8)
   {
   _lread(file_handle, &bitmap->palette,MAX_COLORS_PALETTE*sizeof(PALETTEENTRY));

   // now set all the flags in the palette correctly and fix the reversed 
   // BGR RGBQUAD data format
   for (index=0; index < MAX_COLORS_PALETTE; index++)
       {
       // reverse the red and green fields
       int temp_color                = bitmap->palette[index].peRed;
       bitmap->palette[index].peRed  = bitmap->palette[index].peBlue;
       bitmap->palette[index].peBlue = temp_color;
       
       // always set the flags word to this
       bitmap->palette[index].peFlags = PC_NOCOLLAPSE;
       } // end for index

    } // end if

// finally the image data itself
_lseek(file_handle,-(int)(bitmap->bitmapinfoheader.biSizeImage),SEEK_END);

// now read in the image, if the image is 8 or 16 bit then simply read it
// but if its 24 bit then read it into a temporary area and then convert
// it to a 16 bit image

if (bitmap->bitmapinfoheader.biBitCount==8 || bitmap->bitmapinfoheader.biBitCount==16 || 
    bitmap->bitmapinfoheader.biBitCount==24)
   {
   // delete the last image if there was one
   if (bitmap->buffer)
       free(bitmap->buffer);

   // allocate the memory for the image
   if (!(bitmap->buffer = (UCHAR *)malloc(bitmap->bitmapinfoheader.biSizeImage)))
      {
      // close the file
      _lclose(file_handle);

      // return error
      return(0);
      } // end if

   // now read it in
   _lread(file_handle,bitmap->buffer,bitmap->bitmapinfoheader.biSizeImage);

   } // end if
else
   {
   // serious problem
   return(0);

   } // end else

#if 0
// write the file info out 
printf("\nfilename:%s \nsize=%d \nwidth=%d \nheight=%d \nbitsperpixel=%d \ncolors=%d \nimpcolors=%d",
        filename,
        bitmap->bitmapinfoheader.biSizeImage,
        bitmap->bitmapinfoheader.biWidth,
        bitmap->bitmapinfoheader.biHeight,
		bitmap->bitmapinfoheader.biBitCount,
        bitmap->bitmapinfoheader.biClrUsed,
        bitmap->bitmapinfoheader.biClrImportant);
#endif

// close the file
_lclose(file_handle);

// flip the bitmap
Flip_Bitmap(bitmap->buffer, 
            bitmap->bitmapinfoheader.biWidth*(bitmap->bitmapinfoheader.biBitCount/8), 
            bitmap->bitmapinfoheader.biHeight);

// return success
return(1);

} // end Load_Bitmap_File

///////////////////////////////////////////////////////////

int Unload_Bitmap_File(BITMAP_FILE_PTR bitmap)
{
// this function releases all memory associated with "bitmap"
if (bitmap->buffer)
   {
   // release memory
   free(bitmap->buffer);

   // reset pointer
   bitmap->buffer = NULL;

   } // end if

// return success
return(1);

} // end Unload_Bitmap_File

///////////////////////////////////////////////////////////

int Flip_Bitmap(UCHAR *image, int bytes_per_line, int height)
{
// this function is used to flip bottom-up .BMP images

UCHAR *buffer; // used to perform the image processing
int index;     // looping index

// allocate the temporary buffer
if (!(buffer = (UCHAR *)malloc(bytes_per_line*height)))
   return(0);

// copy image to work area
memcpy(buffer,image,bytes_per_line*height);

// flip vertically
for (index=0; index < height; index++)
    memcpy(&image[((height-1) - index)*bytes_per_line],
           &buffer[index*bytes_per_line], bytes_per_line);

// release the memory
free(buffer);

// return success
return(1);

} // end Flip_Bitmap

///////////////////////////////////////////////////////////////

LRESULT CALLBACK WindowProc(HWND hwnd, 
						    UINT msg, 
                            WPARAM wparam,