i would like advice on the usbject of c programming (in the middle of reading a book on C). could i benefit more if i apply that knowledge in the unix format if i were able to, or would that take the point out of learning C, basically I want to stay away from strying too far away from unix and use... (1 Reply)
Several months ago I found a link that explained the difference between how a Unix Systems Admin would do scripting compared to what a Unix Programmer would do.
It showed a basic script and then show several iterations that explained how the Systems Admin would change it to make it better. I was... (0 Replies)
I am doing the following script in k shell
sed -i 's/FILENAME/$i/g' TEST/test$j.ctl > TEST/control$j.ctl
In the file it replaces $i for all FILENAME, it doesnot replace with the value of i. I put single quotes like below
sed -i 's/FILENAME/'$i'/g' TEST/test$j.ctl > TEST/control$j.ctl
I... (9 Replies)
Hello,
I am trying to learn Networking Programming in C in unix enviorment. I want to know how good it is to become a network programmer. i am crazy about Network programming but i also want to opt for the best carreer options. Anybody experienced Network Programmer, please tell me is my... (5 Replies)
Can someone help me on suggesting some ways to access the memory content in RAM directly from C/C++ source code.
Please provide me any book name or any URL so that I can get an exhaustive
knowledge over it.
If possible please give me some tips on interacting with hardwares directly
through... (3 Replies)
Hello.
I like Linux and C programming language. Allways wanted to understand kernel and become a Linux system programmer. And I also like Objective-C and iOS. These two programming areas have relations:
1. Linux and iOS are UNIX-like systems, POSIX compliant.
2. It is useful to know C language... (2 Replies)
Hi All,
can any one help me on this please.
Replace sting in FILE1.txt with FILE2.txt. FILE1.txt record must have at least one state is repeated once.But need to replace only from second occurrence in record in FILE1.txt
Condition: order of searching the records in FILE2.txt is impartent.... (8 Replies)
I hope my title is accurate enough.
I have a product that we port to various UNIX platforms. It is known to run on AIX but using the IBM compiler from years ago. Recently we got a different used AIX P5 platform running AIX 5.3 and we setup the GCC compiler (4.4.5 I think). C and C++ source code.... (5 Replies)
Dears,
I want to print filename and count of each file in perl but failing to implement.
`find $srcFolder -maxdepth 1 -type f -name "*$workDate*$fileExt" -exec sh -c ' && printf "$workDate|%s|%s\n" "$(wc -l<"$0")" *$workDate*$fileExt' {} \ >> /Sadique/filelog.out \\; 2> /dev/null`;
... (2 Replies)
Discussion started by: sadique.manzar
2 Replies
LEARN ABOUT SUSE
sdl_pixelformat
SDL_PixelFormat(3) SDL API Reference SDL_PixelFormat(3)NAME
SDL_PixelFormat - Stores surface format information
STRUCTURE DEFINITION
typedef struct SDL_PixelFormat {
SDL_Palette *palette;
Uint8 BitsPerPixel;
Uint8 BytesPerPixel;
Uint8 Rloss, Gloss, Bloss, Aloss;
Uint8 Rshift, Gshift, Bshift, Ashift;
Uint32 Rmask, Gmask, Bmask, Amask;
Uint32 colorkey;
Uint8 alpha;
} SDL_PixelFormat;
STRUCTURE DATA
palette Pointer to the palette, or NULL if the BitsPerPixel>8
BitsPerPixel The number of bits used to represent each pixel in a surface. Usually 8, 16, 24 or 32.
BytesPerPixel The number of bytes used to represent each pixel in a surface. Usually one to four.
[RGBA]mask Binary mask used to retrieve individual color values
[RGBA]loss Precision loss of each color component (2^[RGBA]loss)
[RGBA]shift Binary left shift of each color component in the pixel value
colorkey Pixel value of transparent pixels
alpha Overall surface alpha value
DESCRIPTION
A SDL_PixelFormat describes the format of the pixel data stored at the pixels field of a SDL_Surface. Every surface stores a SDL_PixelFor-
mat in the format field.
If you wish to do pixel level modifications on a surface, then understanding how SDL stores its color information is essential.
8-bit pixel formats are the easiest to understand. Since its an 8-bit format, we have 8 BitsPerPixel and 1 BytesPerPixel. Since BytesPer-
Pixel is 1, all pixels are represented by a Uint8 which contains an index into palette->colors. So, to determine the color of a pixel in a
8-bit surface: we read the color index from surface->pixels and we use that index to read the SDL_Color structure from surface->for-
mat->palette->colors. Like so:
SDL_Surface *surface;
SDL_PixelFormat *fmt;
SDL_Color *color;
Uint8 index;
.
.
/* Create surface */
.
.
fmt=surface->format;
/* Check the bitdepth of the surface */
if(fmt->BitsPerPixel!=8){
fprintf(stderr, "Not an 8-bit surface.
");
return(-1);
}
/* Lock the surface */
SDL_LockSurface(surface);
/* Get the topleft pixel */
index=*(Uint8 *)surface->pixels;
color=fmt->palette->colors[index];
/* Unlock the surface */
SDL_UnlockSurface(surface);
printf("Pixel Color-> Red: %d, Green: %d, Blue: %d. Index: %d
",
color->r, color->g, color->b, index);
.
.
Pixel formats above 8-bit are an entirely different experience. They are considered to be "TrueColor" formats and the color information is
stored in the pixels themselves, not in a palette. The mask, shift and loss fields tell us how the color information is encoded. The mask
fields allow us to isolate each color component, the shift fields tell us the number of bits to the right of each component in the pixel
value and the loss fields tell us the number of bits lost from each component when packing 8-bit color component in a pixel.
/* Extracting color components from a 32-bit color value */
SDL_PixelFormat *fmt;
SDL_Surface *surface;
Uint32 temp, pixel;
Uint8 red, green, blue, alpha;
.
.
.
fmt=surface->format;
SDL_LockSurface(surface);
pixel=*((Uint32*)surface->pixels);
SDL_UnlockSurface(surface);
/* Get Red component */
temp=pixel&fmt->Rmask; /* Isolate red component */
temp=temp>>fmt->Rshift;/* Shift it down to 8-bit */
temp=temp<<fmt->Rloss; /* Expand to a full 8-bit number */
red=(Uint8)temp;
/* Get Green component */
temp=pixel&fmt->Gmask; /* Isolate green component */
temp=temp>>fmt->Gshift;/* Shift it down to 8-bit */
temp=temp<<fmt->Gloss; /* Expand to a full 8-bit number */
green=(Uint8)temp;
/* Get Blue component */
temp=pixel&fmt->Bmask; /* Isolate blue component */
temp=temp>>fmt->Bshift;/* Shift it down to 8-bit */
temp=temp<<fmt->Bloss; /* Expand to a full 8-bit number */
blue=(Uint8)temp;
/* Get Alpha component */
temp=pixel&fmt->Amask; /* Isolate alpha component */
temp=temp>>fmt->Ashift;/* Shift it down to 8-bit */
temp=temp<<fmt->Aloss; /* Expand to a full 8-bit number */
alpha=(Uint8)temp;
printf("Pixel Color -> R: %d, G: %d, B: %d, A: %d
", red, green, blue, alpha);
.
.
.
SEE ALSO
SDL_Surface, SDL_MapRGB
SDL Tue 11 Sep 2001, 23:01 SDL_PixelFormat(3)