DRAFT |
SDL_CreateCursor
Use this function to create a cursor using the specified bitmap data and mask (in MSB format).
Contents
Syntax
SDL_Cursor* SDL_CreateCursor(const Uint8* data,
const Uint8* mask,
int w,
int h,
int hot_x,
int hot_y)
Function Parameters
data |
the color value for each pixel of the cursor; see Remarks for details |
mask |
the mask value for each pixel of the cursor; see Remarks for details |
w |
the width of the cursor; see Remarks for details |
h |
the height of the cursor (same restrictions as w?) |
hot_x |
the X-axis location of the upper left corner of the cursor relative to the actual mouse position |
hot_y |
the Y-axis location of the upper left corner of the cursor relative to the actual mouse position |
Return Value
Returns a new cursor with the specified parameters on success or NULL on failure; call SDL_GetError() for more information.
Code Examples
/* Stolen from the mailing list */
/* Creates a new mouse cursor from an XPM */
/* XPM */
static const char *arrow[] = {
/* width height num_colors chars_per_pixel */
" 32 32 3 1",
/* colors */
"X c #000000",
". c #ffffff",
" c None",
/* pixels */
"X ",
"XX ",
"X.X ",
"X..X ",
"X...X ",
"X....X ",
"X.....X ",
"X......X ",
"X.......X ",
"X........X ",
"X.....XXXXX ",
"X..X..X ",
"X.X X..X ",
"XX X..X ",
"X X..X ",
" X..X ",
" X..X ",
" X..X ",
" XX ",
" ",
" ",
" ",
" ",
" ",
" ",
" ",
" ",
" ",
" ",
" ",
" ",
" ",
"0,0"
};
static SDL_Cursor *init_system_cursor(const char *image[])
{
int i, row, col;
Uint8 data[4*32];
Uint8 mask[4*32];
int hot_x, hot_y;
i = -1;
for (row=0; row<32; ++row) {
for (col=0; col<32; ++col) {
if (col % 8) {
data[i] <<= 1;
mask[i] <<= 1;
} else {
++i;
data[i] = mask[i] = 0;
}
switch (image[4+row][col]) {
case 'X':
data[i] |= 0x01;
mask[i] |= 0x01;
break;
case '.':
mask[i] |= 0x01;
break;
case ' ':
break;
}
}
}
sscanf(image[4+row], "%d,%d", &hot_x, &hot_y);
return SDL_CreateCursor(data, mask, 32, 32, hot_x, hot_y);
}
Remarks
mask has to be in MSB (Most Significant Bit) format.
The cursor width (w) must be a multiple of 8 bits.
The cursor is created in black and white according to the following:
data |
mask |
Resulting Pixel on Screen |
0 |
1 |
White |
1 |
1 |
Black |
0 |
0 |
Transparent |
1 |
0 |
Inverted color if possible, black if not |
Cursors created with this function must be freed with SDL_FreeCursor().
If you want to have a color cursor, then this function is not for you; instead, you must hide the normal system cursor using SDL_ShowCursor() and in your main loop, when you draw graphics, also draw a SDL_Surface at the location of the mouse cursor.
Or use SDL_CreateColorCursor().
Note that, since SDL 2.0.0, SDL_CreateSystemCursor() is available, which provides twelve readily available system cursors to pick from.
