agg_win32_bmp.cpp

windows ce 下的画各种b样条曲线

//----------------------------------------------------------------------------
//
//----------------------------------------------------------------------------
// Contact: [e-mail]
//----------------------------------------------------------------------------
//
// class pixel_map
//
//----------------------------------------------------------------------------

#include "agg_win32_bmp.h"
#include "agg_basics.h"

namespace agg
{

    //------------------------------------------------------------------------
    pixel_map::~pixel_map()
    {
        destroy();
    }


    //------------------------------------------------------------------------
    pixel_map::pixel_map() :
        m_bmp(0),
        m_buf(0),
        m_bpp(0),
        m_is_internal(false),
        m_img_size(0),
        m_full_size(0)

    {
    }


    //------------------------------------------------------------------------
    void pixel_map::destroy()
    {
        if(m_bmp && m_is_internal) delete [] (unsigned char*)m_bmp;
        m_bmp  = 0;
        m_is_internal = false;
        m_buf = 0;
    }


    //------------------------------------------------------------------------
    void pixel_map::create(unsigned width, 
                           unsigned height, 
                           org_e    org,
                           unsigned clear_val)
    {
        destroy();
        if(width == 0)  width = 1;
        if(height == 0) height = 1;
        m_bpp = org;
        create_from_bmp(create_bitmap_info(width, height, m_bpp));
        create_gray_scale_palette(m_bmp);
        m_is_internal = true;
        if(clear_val <= 255)
        {
            memset(m_buf, clear_val, m_img_size);
        }
    }


    //------------------------------------------------------------------------
    HBITMAP pixel_map::create_dib_section(HDC h_dc,
                                          unsigned width, 
                                          unsigned height, 
                                          org_e    org,
                                          unsigned clear_val)
    {
        destroy();
        if(width == 0)  width = 1;
        if(height == 0) height = 1;
        m_bpp = org;
        HBITMAP h_bitmap = create_dib_section_from_args(h_dc, width, height, m_bpp);
        create_gray_scale_palette(m_bmp);
        m_is_internal = true;
        if(clear_val <= 255)
        {
            memset(m_buf, clear_val, m_img_size);
        }
        return h_bitmap;
    }



    //------------------------------------------------------------------------
    void pixel_map::clear(unsigned clear_val)
    {
        if(m_buf) memset(m_buf, clear_val, m_img_size);
    }


    //------------------------------------------------------------------------
    void pixel_map::attach_to_bmp(BITMAPINFO *bmp)
    {
        if(bmp)
        {
            destroy();
            create_from_bmp(bmp);
            m_is_internal = false;
        }
    }



    //static
    //------------------------------------------------------------------------
    unsigned pixel_map::calc_full_size(BITMAPINFO *bmp)
    {
        if(bmp == 0) return 0;

        return sizeof(BITMAPINFOHEADER) +
               sizeof(RGBQUAD) * calc_palette_size(bmp) +
               bmp->bmiHeader.biSizeImage;
    }

    //static
    //------------------------------------------------------------------------
    unsigned pixel_map::calc_header_size(BITMAPINFO *bmp)
    {
        if(bmp == 0) return 0;
        return sizeof(BITMAPINFOHEADER) + sizeof(RGBQUAD) * calc_palette_size(bmp);
    }


    //static
    //------------------------------------------------------------------------
    unsigned  pixel_map::calc_palette_size(unsigned  clr_used, unsigned bits_per_pixel)
    {
        int palette_size = 0;

        if(bits_per_pixel <= 8)
        {
            palette_size = clr_used;
            if(palette_size == 0)
            {
                palette_size = 1 << bits_per_pixel;
            }
        }
        return palette_size;
    }

    //static
    //------------------------------------------------------------------------
    unsigned pixel_map::calc_palette_size(BITMAPINFO *bmp)
    {
        if(bmp == 0) return 0;
        return calc_palette_size(bmp->bmiHeader.biClrUsed, bmp->bmiHeader.biBitCount);
    }


    //static
    //------------------------------------------------------------------------
    unsigned char * pixel_map::calc_img_ptr(BITMAPINFO *bmp)
    {
        if(bmp == 0) return 0;
        return ((unsigned char*)bmp) + calc_header_size(bmp);
    }

    //static
    //------------------------------------------------------------------------
    BITMAPINFO* pixel_map::create_bitmap_info(unsigned width, 
                                              unsigned height, 
                                              unsigned bits_per_pixel)
    {
        unsigned line_len = calc_row_len(width, bits_per_pixel);
        unsigned img_size = line_len * height;
        unsigned rgb_size = calc_palette_size(0, bits_per_pixel) * sizeof(RGBQUAD);
        unsigned full_size = sizeof(BITMAPINFOHEADER) + rgb_size + img_size;

        BITMAPINFO *bmp = (BITMAPINFO *) new unsigned char[full_size];

        bmp->bmiHeader.biSize   = sizeof(BITMAPINFOHEADER);
        bmp->bmiHeader.biWidth  = width;
        bmp->bmiHeader.biHeight = height;
        bmp->bmiHeader.biPlanes = 1;
        bmp->bmiHeader.biBitCount = (unsigned short)bits_per_pixel;
        bmp->bmiHeader.biCompression = 0;
        bmp->bmiHeader.biSizeImage = img_size;
        bmp->bmiHeader.biXPelsPerMeter = 0;
        bmp->bmiHeader.biYPelsPerMeter = 0;
        bmp->bmiHeader.biClrUsed = 0;
        bmp->bmiHeader.biClrImportant = 0;

        return bmp;
    }


    //static
    //------------------------------------------------------------------------
    void pixel_map::create_gray_scale_palette(BITMAPINFO *bmp)
    {
        if(bmp == 0) return;

        unsigned rgb_size = calc_palette_size(bmp);
        RGBQUAD *rgb = (RGBQUAD*)(((unsigned char*)bmp) + sizeof(BITMAPINFOHEADER));
        unsigned brightness;
        unsigned i;

        for(i = 0; i < rgb_size; i++)
        {
            brightness = (255 * i) / (rgb_size - 1);
            rgb->rgbBlue =
            rgb->rgbGreen =  
            rgb->rgbRed = (unsigned char)brightness; 
            rgb->rgbReserved = 0;
            rgb++;
        }
    }



    //static
    //------------------------------------------------------------------------
    unsigned pixel_map::calc_row_len(unsigned width, unsigned bits_per_pixel)
    {
        unsigned n = width;
        unsigned k;

        switch(bits_per_pixel)
        {
            case  1: k = n;
                     n = n >> 3;
                     if(k & 7) n++; 
                     break;

            case  4: k = n;
                     n = n >> 1;
                     if(k & 3) n++; 
                     break;

            case  8:
                     break;

            case 16: n *= 2;
                     break;

            case 24: n *= 3; 
                     break;

            case 32: n *= 4;
                     break;

            case 48: n *= 6; 
                     break;

            case 64: n *= 8; 
                     break;

            default: n = 0;
                     break;
        }
        return ((n + 3) >> 2) << 2;
    }





    //------------------------------------------------------------------------
    void pixel_map::draw(HDC h_dc, const RECT *device_rect, const RECT *bmp_rect) const
    {
        if(m_bmp == 0 || m_buf == 0) return;

        unsigned bmp_x = 0;
        unsigned bmp_y = 0;
        unsigned bmp_width  = m_bmp->bmiHeader.biWidth;
        unsigned bmp_height = m_bmp->bmiHeader.biHeight;
        unsigned dvc_x = 0;
        unsigned dvc_y = 0; 
        unsigned dvc_width  = m_bmp->bmiHeader.biWidth;
        unsigned dvc_height = m_bmp->bmiHeader.biHeight;
        
        if(bmp_rect) 
        {
            bmp_x      = bmp_rect->left;
            bmp_y      = bmp_rect->top;
            bmp_width  = bmp_rect->right  - bmp_rect->left;
            bmp_height = bmp_rect->bottom - bmp_rect->top;
        } 

        dvc_x      = bmp_x;
        dvc_y      = bmp_y;
        dvc_width  = bmp_width;
        dvc_height = bmp_height;

        if(device_rect) 
        {
            dvc_x      = device_rect->left;
            dvc_y      = device_rect->top;
            dvc_width  = device_rect->right  - device_rect->left;
            dvc_height = device_rect->bottom - device_rect->top;
        }

        if(dvc_width != bmp_width || dvc_height != bmp_height)
        {
            ::SetStretchBltMode(h_dc, COLORONCOLOR);
            ::StretchDIBits(
                h_dc,            // handle of device context 
                dvc_x,           // x-coordinate of upper-left corner of source rect. 
                dvc_y,           // y-coordinate of upper-left corner of source rect. 
                dvc_width,       // width of source rectangle 
                dvc_height,      // height of source rectangle 
                bmp_x,
                bmp_y,           // x, y -coordinates of upper-left corner of dest. rect. 
                bmp_width,       // width of destination rectangle 
                bmp_height,      // height of destination rectangle 
                m_buf,           // address of bitmap bits 
                m_bmp,           // address of bitmap data