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SDL_CreateCursor

Use this function to create a cursor using the specified bitmap data and mask (in MSB format).

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.


CategoryAPI, CategoryMouse

None: SDL_CreateCursor (last edited 2017-07-14 21:57:48 by PhilippWiesemann)

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