Ignore:
Timestamp:
Sep 28, 2008, 7:08:11 AM (12 years ago)
Author:
Sam Hocevar
Message:

gdi.c: the GDI codec can now open and save BMP files.

File:
1 edited

Legend:

Unmodified
Added
Removed
  • libpipi/trunk/pipi/codec/gdi.c

    r2839 r2840  
     1/*
     2 *  libpipi       Proper image processing implementation library
     3 *  Copyright (c) 2004-2008 Sam Hocevar <sam@zoy.org>
     4 *                All Rights Reserved
     5 *
     6 *  $Id$
     7 *
     8 *  This library is free software. It comes without any warranty, to
     9 *  the extent permitted by applicable law. You can redistribute it
     10 *  and/or modify it under the terms of the Do What The Fuck You Want
     11 *  To Public License, Version 2, as published by Sam Hocevar. See
     12 *  http://sam.zoy.org/wtfpl/COPYING for more details.
     13 */
     14
     15/*
     16 * gdi.c: Windows GDI I/O functions (BMP only)
     17 */
     18
     19#include "config.h"
     20#include "common.h"
     21
     22#include <stdio.h>
     23#include <stdlib.h>
     24#include <string.h>
     25
     26#include <windows.h>
     27
     28#include "pipi.h"
     29#include "pipi_internals.h"
     30
     31pipi_image_t *pipi_load_gdi(const char *name)
     32{
     33    BITMAPINFO binfo;
     34    pipi_image_t *img;
     35    pipi_pixels_t *p;
     36    uint8_t *data;
     37    HBITMAP hbmap;
     38    HDC hdc;
     39    int x, y;
     40
     41    hbmap = (HBITMAP)LoadImage(NULL, name, IMAGE_BITMAP, 0, 0, LR_LOADFROMFILE);
     42    if(!hbmap)
     43        return NULL;
     44
     45    hdc = CreateCompatibleDC(NULL);
     46    SelectObject(hdc, hbmap);
     47
     48    memset(&binfo, 0, sizeof(binfo));
     49    binfo.bmiHeader.biSize = sizeof(binfo.bmiHeader);
     50    if(!GetDIBits(hdc, hbmap, 0, 0, 0, &binfo, DIB_RGB_COLORS))
     51    {
     52        ReleaseDC(0, hdc);
     53        DeleteObject(hbmap);
     54        return NULL;
     55    }
     56
     57    img = pipi_new(binfo.bmiHeader.biWidth, binfo.bmiHeader.biHeight);
     58    p = pipi_getpixels(img, PIPI_PIXELS_RGBA_C);
     59    data = p->pixels;
     60
     61    binfo.bmiHeader.biBitCount = 32;
     62    binfo.bmiHeader.biCompression = BI_RGB;
     63    binfo.bmiHeader.biHeight = - abs(binfo.bmiHeader.biHeight);
     64    if(!GetDIBits(hdc, hbmap, 0, binfo.bmiHeader.biHeight, data,
     65                  &binfo, DIB_RGB_COLORS))
     66    {
     67        ReleaseDC(0, hdc);
     68        DeleteObject(hbmap);
     69        return NULL;
     70    }
     71
     72    /* FIXME: get rid of this loop, maybe by using BITMAPV4HEADER above
     73     * so that GDI reorders the pixels for us. */
     74    for(y = 0; y < img->h; y++)
     75        for(x = 0; x < img->w; x++)
     76        {
     77            /* Swap B and R, don't touch G and A. */
     78            uint8_t tmp = data[0]; data[0] = data[2]; data[2] = tmp;
     79            data += 4;
     80        }
     81
     82    img->codec_priv = NULL;
     83
     84    img->wrap = 0;
     85    img->u8 = 1;
     86
     87    ReleaseDC(0, hdc);
     88    DeleteObject(hbmap);
     89
     90    return img;
     91}
     92
     93int pipi_save_gdi(pipi_image_t *img, const char *name)
     94{
     95    BITMAPINFOHEADER binfo;
     96    BITMAPFILEHEADER bfheader;
     97    uint8_t dummy[4] = { 0 };
     98    HANDLE hfile;
     99    pipi_pixels_t *p;
     100    DWORD ret = 0;
     101    uint8_t *data;
     102    int x, y, padding;
     103
     104    p = pipi_getpixels(img, PIPI_PIXELS_RGBA_C);
     105    data = p->pixels;
     106
     107    padding = ((img->w * 3) + 3) / 4 * 4 - img->w * 3;
     108
     109    memset(&binfo, 0, sizeof(binfo));
     110    binfo.biSize = sizeof(binfo);
     111    binfo.biWidth = img->w;
     112    binfo.biHeight = img->h;
     113    binfo.biPlanes = 1;
     114    binfo.biBitCount = 24;
     115    binfo.biCompression = BI_RGB;
     116    binfo.biSizeImage = (img->w * 3 + padding) * img->h;
     117
     118    memset(&bfheader, 0, sizeof(bfheader));
     119    bfheader.bfType = 0x4D42;
     120    bfheader.bfOffBits = sizeof(bfheader) + sizeof(binfo);
     121    bfheader.bfSize = bfheader.bfOffBits + binfo.biSizeImage;
     122
     123    /* We don’t even create the bitmap object, since we know exactly
     124     * what kind of file we are saving. But later, when we support
     125     * different depths and BMP options, we'll need to care about it. */
     126    hfile = CreateFile(name, GENERIC_WRITE, 0, NULL, CREATE_ALWAYS,
     127                       FILE_ATTRIBUTE_ARCHIVE, NULL);
     128    if(!hfile)
     129        return -1;
     130    WriteFile(hfile, &bfheader, sizeof(bfheader), &ret, NULL);
     131    WriteFile(hfile, &binfo, sizeof(binfo), &ret, NULL);
     132    for(y = 0; y < img->h; y++)
     133    {
     134        for(x = 0; x < img->w; x++)
     135        {
     136            uint8_t tmp[3];
     137            tmp[0] = data[4 * (img->w * (img->h - 1 - y) + x) + 2];
     138            tmp[1] = data[4 * (img->w * (img->h - 1 - y) + x) + 1];
     139            tmp[2] = data[4 * (img->w * (img->h - 1 - y) + x) + 0];
     140            WriteFile(hfile, tmp, 3, &ret, NULL);
     141        }
     142        if(padding)
     143            WriteFile(hfile, dummy, padding, &ret, NULL);
     144    }
     145    CloseHandle(hfile);
     146
     147    return 0;
     148}
     149
     150/*
     151 * XXX: The following functions are local.
     152 */
     153
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