// gdi32.c - Win32 Graphics Device Interface stubs
#include <stdint.h>
#include <stddef.h>

// ---------------------------------------------------------------------------
// Syscall stubs (from syscall.dll)
// ---------------------------------------------------------------------------
extern void SysScreenBlit(int x, int y, int w, int h, const uint32_t* pixels);

// ---------------------------------------------------------------------------
// Win32 Base Types
// ---------------------------------------------------------------------------
typedef void* HDC;
typedef unsigned long  DWORD;
typedef unsigned short WORD;
typedef unsigned int   UINT;
typedef long           LONG;
typedef int            BOOL;

#define TRUE  1
#define FALSE 0

// StretchDIBits Constants
#define BI_RGB          0L
#define DIB_RGB_COLORS  0
#define SRCCOPY         (DWORD)0x00CC0020

// ---------------------------------------------------------------------------
// GDI Structs
// ---------------------------------------------------------------------------
typedef struct tagBITMAPINFOHEADER {
    DWORD biSize;
    LONG  biWidth;
    LONG  biHeight;
    WORD  biPlanes;
    WORD  biBitCount;
    DWORD biCompression;
    DWORD biSizeImage;
    LONG  biXPelsPerMeter;
    LONG  biYPelsPerMeter;
    DWORD biClrUsed;
    DWORD biClrImportant;
} BITMAPINFOHEADER;

typedef struct tagRGBQUAD {
    unsigned char rgbBlue;
    unsigned char rgbGreen;
    unsigned char rgbRed;
    unsigned char rgbReserved;
} RGBQUAD;

typedef struct tagBITMAPINFO {
    BITMAPINFOHEADER bmiHeader;
    RGBQUAD          bmiColors[1];
} BITMAPINFO;

// ---------------------------------------------------------------------------
// GDI Exports
// ---------------------------------------------------------------------------
__declspec(dllexport) int StretchDIBits(
    HDC hdc,
    int xDest, int yDest, int DestWidth, int DestHeight,
    int xSrc, int ySrc, int SrcWidth, int SrcHeight,
    const void *lpBits, const BITMAPINFO *lpbmi,
    UINT iUsage, DWORD rop) 
{
    (void)hdc; (void)xSrc; (void)ySrc; (void)SrcWidth; (void)SrcHeight;
    (void)lpbmi; (void)iUsage; (void)rop;

    // Direct mapping to kernel screen blit
    SysScreenBlit(xDest, yDest, DestWidth, DestHeight, (const uint32_t*)lpBits);

    // Return the number of scanlines copied
    return DestHeight; 
}

__declspec(dllexport) BOOL BitBlt(HDC hdcDest, int xDest, int yDest, int w, int h, 
                                  HDC hdcSrc, int xSrc, int ySrc, DWORD rop) {
    (void)hdcDest; (void)xDest; (void)yDest; (void)w; (void)h;
    (void)hdcSrc; (void)xSrc; (void)ySrc; (void)rop;
    // Stubbed. Applications manipulating pixels directly will use StretchDIBits.
    return TRUE; 
}