/*  Starshatter: The Open Source Project
    Copyright (c) 2021-2024, Starshatter: The Open Source Project Contributors
    Copyright (c) 2011-2012, Starshatter OpenSource Distribution Contributors
    Copyright (c) 1997-2006, Destroyer Studios LLC.

    AUTHOR:       John DiCamillo


    OVERVIEW
    ========
    BMP image file loader
*/


#include "Bmp.h"

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "Types.h"

// +--------------------------------------------------------------------+

BmpImage::BmpImage()
    : width(0), height(0), image(0)
{ }

BmpImage::BmpImage(short w, short h, unsigned long* hibits)
{
    ZeroMemory(this, sizeof(BmpImage));

    width                = w;
    height               = h;

    file_hdr.type        = 19778;    // 'BM'
    file_hdr.size        = sizeof(BmpFileHeader) +
    sizeof(BmpInfoHeader) +
    w * h * 3;

    file_hdr.offset      = sizeof(BmpFileHeader) +
    sizeof(BmpInfoHeader);

    info_hdr.hdr_size    = sizeof(BmpInfoHeader);
    info_hdr.width       = width;
    info_hdr.height      = height;
    info_hdr.planes      = 1;
    info_hdr.bit_count   = 24;

    int pixels           = width * height;

    image = new DWORD [pixels];

    if (image && pixels) {
        for (int i = 0; i < pixels; i++)
        image[i] = hibits[i];
    }
}

BmpImage::~BmpImage()
{
    delete [] image;
}

// +--------------------------------------------------------------------+

int BmpImage::Load(char *filename)
{
    int   status = BMP_INVALID;
    FILE* f;

    fopen_s(&f, filename,"rb");
    if (f == NULL)
    return BMP_NOFILE;

    fread(&file_hdr.type,   sizeof(WORD),      1, f);
    fread(&file_hdr.size,   sizeof(DWORD),     1, f);
    fread(&file_hdr.rsvd1,  sizeof(WORD),      1, f);
    fread(&file_hdr.rsvd2,  sizeof(WORD),      1, f);
    fread(&file_hdr.offset, sizeof(DWORD),     1, f);
    fread(&info_hdr,        BMP_INFO_HDR_SIZE, 1, f);

    if (info_hdr.width > 32768 || info_hdr.height > 32768 ||
            (info_hdr.width&3) || (info_hdr.height&3) ||
            info_hdr.compression != 0) {
        fclose(f);
        return BMP_INVALID;
    }

    width    = (WORD) info_hdr.width;
    height   = (WORD) info_hdr.height;

    // read 256 color BMP file
    if (info_hdr.bit_count == 8) {
        fread(palette, sizeof(palette), 1, f);

        int pixels = width*height;

        delete [] image;
        image = new DWORD[pixels];
        if (image == NULL)
        return BMP_NOMEM;

        for (int row = height-1; row >= 0; row--) {
            for (int col = 0; col < width; col++) {
                BYTE index = fgetc(f);
                image[row*width+col] = palette[index];
            }
        }

        status = BMP_OK;
    }

    // read 24-bit (true COLOR) BMP file
    else if (info_hdr.bit_count == 24) {
        int pixels = width*height;

        delete [] image;
        image = new DWORD[pixels];
        if (image == NULL)
        return BMP_NOMEM;

        for (int row = height-1; row >= 0; row--) {
            for (int col = 0; col < width; col++) {
                DWORD blue  = fgetc(f);
                DWORD green = fgetc(f);
                DWORD red   = fgetc(f);

                image[row*width+col] = 0xff000000 | (red << 16) | (green << 8) | blue;
            }
        }

        status = BMP_OK;
    }

    fclose(f);
    return status;
}

// +--------------------------------------------------------------------+

int BmpImage::LoadBuffer(unsigned char* buf, int len)
{
    int   status = BMP_INVALID;
    BYTE* fp;

    if (buf == NULL)
    return BMP_NOFILE;

    fp = buf;
    memcpy(&info_hdr, buf + BMP_FILE_HDR_SIZE, BMP_INFO_HDR_SIZE);
    fp += BMP_FILE_HDR_SIZE + BMP_INFO_HDR_SIZE;

    if (info_hdr.width > 32768 || info_hdr.height > 32768 ||
            (info_hdr.width&3) || (info_hdr.height&3) ||
            info_hdr.compression != 0) {
        return BMP_INVALID;
    }

    width    = (WORD) info_hdr.width;
    height   = (WORD) info_hdr.height;

    // read 256 color BMP file
    if (info_hdr.bit_count == 8) {
        memcpy(palette, fp, sizeof(palette));
        fp += sizeof(palette);

        int pixels = width*height;

        delete [] image;
        image = new DWORD[pixels];
        if (image == NULL)
        return BMP_NOMEM;

        for (int row = height-1; row >= 0; row--) {
            for (int col = 0; col < width; col++) {
                BYTE index = *fp++;
                image[row*width+col] = palette[index];
            }
        }

        status = BMP_OK;
    }

    // read 24-bit (true COLOR) BMP file
    else if (info_hdr.bit_count == 24) {
        int pixels = width*height;

        delete [] image;
        image = new DWORD[pixels];
        if (image == NULL)
        return BMP_NOMEM;

        for (int row = height-1; row >= 0; row--) {
            for (int col = 0; col < width; col++) {
                DWORD blue  = *fp++;
                DWORD green = *fp++;
                DWORD red   = *fp++;

                image[row*width+col] = 0xff000000 | (red << 16) | (green << 8) | blue;
            }
        }

        status = BMP_OK;
    }

    return status;
}

// +--------------------------------------------------------------------+

int BmpImage::Save(char *filename)
{
    int   status = BMP_INVALID;
    FILE* f;

    fopen_s(&f, filename,"wb");
    if (f == NULL)
    return BMP_NOFILE;

    info_hdr.bit_count   = 24;
    info_hdr.compression = 0;

    fwrite(&file_hdr.type,   sizeof(WORD),      1, f);
    fwrite(&file_hdr.size,   sizeof(DWORD),     1, f);
    fwrite(&file_hdr.rsvd1,  sizeof(WORD),      1, f);
    fwrite(&file_hdr.rsvd2,  sizeof(WORD),      1, f);
    fwrite(&file_hdr.offset, sizeof(DWORD),     1, f);
    fwrite(&info_hdr,        BMP_INFO_HDR_SIZE, 1, f);

    // write 24-bit (TRUE COLOR) BMP file
    for (int row = height-1; row >= 0; row--) {
        for (int col = 0; col < width; col++) {
            DWORD pixel = image[row*width+col];

            BYTE blue  = (BYTE) ((pixel & 0x000000ff) >>  0);
            BYTE green = (BYTE) ((pixel & 0x0000ff00) >>  8);
            BYTE red   = (BYTE) ((pixel & 0x00ff0000) >> 16);

            fwrite(&blue,  1, 1, f);
            fwrite(&green, 1, 1, f);
            fwrite(&red,   1, 1, f);
        }
    }

    status = BMP_OK;

    fclose(f);
    return status;
}