. I know that a certain pixel (e.g. 12,20) has a pixel of:red-10
green-243
blue-0
yet, I seem to be getting wrong result. Can anyone help me?
How to get a pixel from a surface?
Author
Hmm. GetRValue, GetGValue and GetBValue doesn''t seem to work . I know that a certain pixel (e.g. 12,20) has a pixel of:
red-10
green-243
blue-0
yet, I seem to be getting wrong result. Can anyone help me?
. I know that a certain pixel (e.g. 12,20) has a pixel of:red-10
green-243
blue-0
yet, I seem to be getting wrong result. Can anyone help me?
quote:Original post by s_cloudx
Hmm. GetRValue, GetGValue and GetBValue doesn''t seem to work
red-10
green-243
blue-0
yet, I seem to be getting wrong result. Can anyone help me?
If your prog is running in, say, 16bit colour, it''ll have to convert to get your the 32bit COLORREF containing 8bit values. A full white pixel in 16bit mode might contain (248, 252, 248) in 32bit mode.
Author
Maybe I should had been more specific.
On photoshop, I check the color of a pixel location (eg. 12,20). Photoshop says it has a color of
red-10
green-243
blue-0
But I get mixed result when I try to get the color. Can someone give me a code on how to get the right color, pls?
On photoshop, I check the color of a pixel location (eg. 12,20). Photoshop says it has a color of
red-10
green-243
blue-0
But I get mixed result when I try to get the color. Can someone give me a code on how to get the right color, pls?
typedef union
{
struct
{
BYTE b;
BYTE g;
BYTE r;
} rgb;
struct
{
BYTE r;
BYTE g;
BYTE b;
} bgr;
} TRIPLE, *LPTRIPLE;
LPWORD pWord;
LPTRIPLE pTriple;
LPDWORD pDword;
DWORD dwColor, dwRed, dwGreen, dwBlue;
hr = m_pBackSurface->Lock(NULL, &ddsd,
DDLOCK_WAIT | DDLOCK_SURFACEMEMORYPTR,
NULL);
// 16 bits
pWord = (LPWORD)ddsd.lpSurface + ((ddsd.lPitch / 2) * y) + x;
dwColor = (DWORD)(*pWord);
// 24 bits
pTriple = (LPTRIPLE)ddsd.lpSurface + ((ddsd.lPitch / 3) * y) + x;
dwRed = (DWORD)pTriple->rgb.r;
dwGreen = (DWORD)pTriple->rgb.g;
dwBlue = (DWORD)pTriple->rgb.b;
dwColor = (dwRed << 16) | (dwGreen << 8) | (dwBlue);
// or
dwRed = (DWORD)pTriple->bgr.r;
dwGreen = (DWORD)pTriple->bgr.g;
dwBlue = (DWORD)pTriple->bgr.b;
dwColor = (dwRed) | (dwGreen << 8) | (dwBlue << 16);
// 32 bits
pDword = (LPDWORD)ddsd.lpSurface + ((ddsd.lPitch / 4) * y) + x;
dwColor = (DWORD)(*pDword);
hr = m_pBackSurface->Unlock(NULL);
Made In Taiwan
{
struct
{
BYTE b;
BYTE g;
BYTE r;
} rgb;
struct
{
BYTE r;
BYTE g;
BYTE b;
} bgr;
} TRIPLE, *LPTRIPLE;
LPWORD pWord;
LPTRIPLE pTriple;
LPDWORD pDword;
DWORD dwColor, dwRed, dwGreen, dwBlue;
hr = m_pBackSurface->Lock(NULL, &ddsd,
DDLOCK_WAIT | DDLOCK_SURFACEMEMORYPTR,
NULL);
// 16 bits
pWord = (LPWORD)ddsd.lpSurface + ((ddsd.lPitch / 2) * y) + x;
dwColor = (DWORD)(*pWord);
// 24 bits
pTriple = (LPTRIPLE)ddsd.lpSurface + ((ddsd.lPitch / 3) * y) + x;
dwRed = (DWORD)pTriple->rgb.r;
dwGreen = (DWORD)pTriple->rgb.g;
dwBlue = (DWORD)pTriple->rgb.b;
dwColor = (dwRed << 16) | (dwGreen << 8) | (dwBlue);
// or
dwRed = (DWORD)pTriple->bgr.r;
dwGreen = (DWORD)pTriple->bgr.g;
dwBlue = (DWORD)pTriple->bgr.b;
dwColor = (dwRed) | (dwGreen << 8) | (dwBlue << 16);
// 32 bits
pDword = (LPDWORD)ddsd.lpSurface + ((ddsd.lPitch / 4) * y) + x;
dwColor = (DWORD)(*pDword);
hr = m_pBackSurface->Unlock(NULL);
Made In Taiwan
Author
Anon: I might be missing something, but how can I extract the RGB in 16-bit color? I''ll see later when I get home and try your code.
// 16 bits
pWord = (LPWORD)ddsd.lpSurface + ((ddsd.lPitch / 2) * y) + x;
wColor = *pWord;
// 16 bits R5G5B5
wRed = (wColor & 0x7C00) >> 10;
wGreen = (wColor & 0x03E0) >> 5;
wBlue = (wColor & 0x001F);
// 16 bits R5G6B5
wRed = (wColor & 0xF800) >> 11;
wGreen = (wColor & 0x07E0) >> 5;
wBlue = (wColor & 0x001F);
Made In Taiwan
Author
Anon, it still doesn''t work
Using your code, I get:
R - 15
G - 30
B - 8
I''m expecting (i checked the color with photoshop):
R - 248
G - 240
B - 64
or, am I missing something? my guess would be that I''m getting the correct colors information but photoshop is giving me a different color format.
Kippesoep, I believed you were right. Maybe what I really need right now is to convert 16bit (or even 32bit) to 8bit. So, how do I do that?
Using your code, I get:
R - 15
G - 30
B - 8
I''m expecting (i checked the color with photoshop):
R - 248
G - 240
B - 64
or, am I missing something? my guess would be that I''m getting the correct colors information but photoshop is giving me a different color format.
Kippesoep, I believed you were right. Maybe what I really need right now is to convert 16bit (or even 32bit) to 8bit. So, how do I do that?
I''ll just throw a little something in here.
A little re-write of what I use in my 16 bit sprite library.
Then extract colours using AP''s equations.
This assumes surface is made in system memory.
Guy
"Who lives in a pineapple under the sea ?"
A little re-write of what I use in my 16 bit sprite library.
USHORT *surf_ptr;USHORT colour;DDSURFACEDESC2 ddsd;ddsd.dwSize = sizeof(ddsd);if ( surface == NULL ) return; // let''s get some surface info surface -> GetSurfaceDesc( &ddsd ); ( surface ) -> Lock( NULL, &ddsd, DDLOCK_WAIT | DDLOCK_SURFACEMEMORYPTR, NULL); surf_ptr = (USHORT *)ddsd.lpSurface; ( surface ) -> Unlock(NULL); colour = *(surf_ptr + ( y * ddsd.dwWidth ) + x ); Then extract colours using AP''s equations.
This assumes surface is made in system memory.
Guy
"Who lives in a pineapple under the sea ?"
quote:Original post by s_cloudx
or, am I missing something? my guess would be that I'm getting the correct colors information but photoshop is giving me a different color format.
Kippesoep, I believed you were right. Maybe what I really need right now is to convert 16bit (or even 32bit) to 8bit. So, how do I do that?
You're getting a different range. There are two ways to convert: the fast way and the accurate way.
First, the fast way:
16bit R5G5B5finalRed = wRed << 3;finalGreen = wGreen << 3;finalBlue = wBlue << 3;16bit R5G6B5finalRed = wRed << 3;finalGreen = wGreen << 2;finalBlue = wBlue << 3; The accurate way:
16bit R5G5B5finalRed = wRed * 255 / 31;finalGreen = wGreen * 255 / 31;finalBlue = wBlue * 255 / 31;16bit R5G6B5finalRed = wRed * 255 / 31;finalGreen = wGreen * 255 / 63;finalBlue = wBlue * 255 / 63; You could speed that up using two lookup tables (a total of 96 bytes):
unsigned char table5bit [32];unsigned char table6bit [64];void initTables (){ int i; for (i = 0; i < 32; i++) table5bit [i] = (unsigned char)(i * 255 / 31); for (i = 0; i < 64; i++) table6bit [i] = (unsigned char)(i * 255 / 63);} 16bit R5G5B5finalRed = table5bit [wRed];finalGreen = table5bit [wGreen];finalBlue = table5bit [wBlue];16bit R5G6B5finalRed = table5bit [wRed];finalGreen = table6bit [wGreen];finalBlue = table5bit [wBlue]; [edited by - Kippesoep on March 15, 2002 1:27:16 PM]
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