ref: 61492029a54f3caa60c9693ded94b0de09470e1a
dir: /demos/graph/grobjs.c/
#include "grobjs.h"
#include <stdlib.h>
#include <string.h>
int grError = 0;
/********************************************************************
*
* <Function>
* grRealloc
*
* <Description>
* Simple memory re-allocation.
*
* <Input>
* block :: original memory block address
* size :: new requested block size in bytes
*
* <Return>
* the memory block address. 0 in case of error
*
********************************************************************/
char* grAlloc( long size )
{
char* p;
p = (char*)malloc(size);
if (!p && size > 0)
{
grError = gr_err_memory;
}
if (p)
memset( p, 0, size );
return p;
}
/********************************************************************
*
* <Function>
* grRealloc
*
* <Description>
* Simple memory re-allocation.
*
* <Input>
* block :: original memory block address
* size :: new requested block size in bytes
*
* <Return>
* the memory block address. 0 in case of error
*
********************************************************************/
char* grRealloc( const char* block, long size )
{
char* p;
p = realloc( (char*)block, size );
if (!p && size > 0)
{
grError = gr_err_memory;
}
return p;
}
/********************************************************************
*
* <Function>
* grFree
*
* <Description>
* Simple memory release
*
* <Input>
* block :: target block
*
********************************************************************/
void grFree( const void* block )
{
if (block)
free( (char*)block );
}
static
int check_mode( grPixelMode pixel_mode,
int num_grays )
{
if ( pixel_mode <= gr_pixel_mode_none ||
pixel_mode >= gr_pixel_mode_max )
goto Fail;
if ( pixel_mode != gr_pixel_mode_gray ||
( num_grays >= 2 && num_grays < 256 ) )
return 0;
Fail:
grError = gr_err_bad_argument;
return grError;
}
/**********************************************************************
*
* <Function>
* grNewBitmap
*
* <Description>
* creates a new bitmap
*
* <Input>
* pixel_mode :: the target surface's pixel_mode
* num_grays :: number of grays levels for PAL8 pixel mode
* width :: width in pixels
* height :: height in pixels
*
* <Output>
* bit :: descriptor of the new bitmap
*
* <Return>
* Error code. 0 means success.
*
**********************************************************************/
extern int grNewBitmap( grPixelMode pixel_mode,
int num_grays,
int width,
int height,
grBitmap *bit )
{
int pitch;
/* check mode */
if (check_mode(pixel_mode,num_grays))
goto Fail;
/* check dimensions */
if (width < 0 || height < 0)
{
grError = gr_err_bad_argument;
goto Fail;
}
bit->width = width;
bit->rows = height;
bit->mode = pixel_mode;
bit->grays = num_grays;
pitch = width;
switch (pixel_mode)
{
case gr_pixel_mode_mono : pitch = (width+7) >> 3; break;
case gr_pixel_mode_pal4 : pitch = (width+3) >> 2; break;
case gr_pixel_mode_pal8 :
case gr_pixel_mode_gray : pitch = width; break;
case gr_pixel_mode_rgb555:
case gr_pixel_mode_rgb565: pitch = width*2; break;
case gr_pixel_mode_rgb24 : pitch = width*3; break;
case gr_pixel_mode_rgb32 : pitch = width*4; break;
default:
grError = gr_err_bad_target_depth;
return 0;
}
bit->pitch = pitch;
bit->buffer = grAlloc( (long)bit->pitch * bit->rows );
if (!bit->buffer) goto Fail;
return 0;
Fail:
return grError;
}
/**********************************************************************
*
* <Function>
* grDoneBitmap
*
* <Description>
* destroys a bitmap
*
* <Input>
* bitmap :: handle to bitmap descriptor
*
* <Note>
* This function does NOT release the bitmap descriptor, only
* the pixel buffer.
*
**********************************************************************/
extern void grDoneBitmap( grBitmap* bit )
{
grFree( bit->buffer );
bit->buffer = 0;
}