gnuboy-for-dfi/sys/thinlib/lib/tl_bmp.c

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/*
** thinlib (c) 2001 Matthew Conte (matt@conte.com)
**
**
** tl_bmp.c
**
** Bitmap object manipulation routines
**
** $Id: $
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "tl_types.h"
#include "tl_bmp.h"
#define BPP_PITCH(pitch, bpp) ((pitch) * (((bpp) + 7) / 8))
/* TODO: you can make this faster. */
void thin_bmp_clear(const bitmap_t *bitmap, uint8 color)
{
memset(bitmap->data, color, bitmap->pitch * bitmap->height);
}
static bitmap_t *_make_bitmap(uint8 *data_addr, bool hw, int width,
int height, int bpp, int pitch, int overdraw)
{
bitmap_t *bitmap;
int i;
/* sometimes our data address is zero; for instance, setting
** video selectors for VESA mode with far pointers. so we
** don't want to bail out if we're passed a zero address.
*/
/* Make sure to add in space for line pointers */
bitmap = malloc(sizeof(bitmap_t) + (sizeof(uint8 *) * height));
if (NULL == bitmap)
return NULL;
bitmap->hardware = hw;
bitmap->height = height;
bitmap->width = width;
bitmap->bpp = bpp;
bitmap->data = data_addr;
bitmap->pitch = BPP_PITCH(pitch, bpp);
/* Set up line pointers */
bitmap->line[0] = bitmap->data + overdraw;
for (i = 1; i < height; i++)
bitmap->line[i] = bitmap->line[i - 1] + bitmap->pitch;
return bitmap;
}
/* Allocate and initialize a bitmap structure */
bitmap_t *thin_bmp_create(int width, int height, int bpp, int overdraw)
{
uint8 *addr;
/* left and right overdraw */
int pitch = width + (overdraw * 2);
/* dword align */
pitch = (pitch + 3) & ~3;
addr = malloc(height * BPP_PITCH(pitch, bpp));
if (NULL == addr)
return NULL;
return _make_bitmap(addr, false, width, height, bpp, pitch, overdraw);
}
/* allocate and initialize a hardware bitmap */
bitmap_t *thin_bmp_createhw(uint8 *addr, int width, int height, int bpp, int pitch)
{
return _make_bitmap(addr, true, width, height, bpp, pitch, 0); /* zero overdraw */
}
/* Deallocate space for a bitmap structure */
void thin_bmp_destroy(bitmap_t **bitmap)
{
if (*bitmap)
{
if ((*bitmap)->data && false == (*bitmap)->hardware)
free((*bitmap)->data);
free(*bitmap);
*bitmap = NULL;
}
}
/*
** $Log: $
*/