在 .cpp 中调用 .c 文件

我正在尝试从 C++ 文件 (main.cpp) 调用 C 文件 (dispmanx.c)。

dispmanx.c :

#ifdef __cplusplus
extern "C" {
#endif

#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <assert.h>
#include <unistd.h>
#include <sys/time.h>

#include "bcm_host.h"

#define WIDTH   200
#define HEIGHT  200

#ifndef ALIGN_UP
#define ALIGN_UP(x,y)  ((x + (y)-1) & ~((y)-1))
#endif

int run(unsigned char* fileData)
{
    typedef struct
    {
        DISPMANX_DISPLAY_HANDLE_T   display;
        DISPMANX_MODEINFO_T         info;
        void                       *image;
        DISPMANX_UPDATE_HANDLE_T    update;
        DISPMANX_RESOURCE_HANDLE_T  resource;
        DISPMANX_ELEMENT_HANDLE_T   element;
        uint32_t                    vc_image_ptr;

    } RECT_VARS_T;

    static RECT_VARS_T  gRectVars;


    RECT_VARS_T    *vars;
    uint32_t        screen = 1;
    int             ret;
    VC_RECT_T       src_rect;
    VC_RECT_T       dst_rect;
    VC_IMAGE_TYPE_T type = VC_IMAGE_RGB565;
    int width = WIDTH, height = HEIGHT;
    int pitch = ALIGN_UP(width*2, 32);
    int aligned_height = ALIGN_UP(height, 16);
    VC_DISPMANX_ALPHA_T alpha = { DISPMANX_FLAGS_ALPHA_FROM_SOURCE | DISPMANX_FLAGS_ALPHA_FIXED_ALL_PIXELS, 
                             120, /*alpha 0->255*/
                             0 };

    vars = &gRectVars;

    bcm_host_init();

    printf("Open display[%i]...\n", screen );
    vars->display = vc_dispmanx_display_open( screen );

    ret = vc_dispmanx_display_get_info( vars->display, &vars->info);
    assert(ret == 0);
    printf( "Display is %d x %d\n", vars->info.width, vars->info.height );

    vars->image = fileData;

//  vars->image = calloc(1, pitch * height);
    assert(vars->image);

    vars->resource = vc_dispmanx_resource_create( type,
                                                  width,
                                                  height,
                                                  &vars->vc_image_ptr );
    assert( vars->resource );
    vc_dispmanx_rect_set( &dst_rect, 0, 0, width, height);
    ret = vc_dispmanx_resource_write_data(  vars->resource,
                                            type,
                                            pitch,
                                            vars->image,
                                            &dst_rect );


    assert( ret == 0 );
    vars->update = vc_dispmanx_update_start( 10 );
    assert( vars->update );

    vc_dispmanx_rect_set( &src_rect, 0, 0, width << 16, height << 16 );

    vc_dispmanx_rect_set( &dst_rect, ( vars->info.width - width ) / 2,
                                     ( vars->info.height - height ) / 2,
                                     width,
                                     height );

    vars->element = vc_dispmanx_element_add(    vars->update,
                                                vars->display,
                                                2000,               // layer
                                                &dst_rect,
                                                vars->resource,
                                                &src_rect,
                                                DISPMANX_PROTECTION_NONE,
                                                &alpha,
                                                NULL,             // clamp
                                                VC_IMAGE_ROT0 );

    ret = vc_dispmanx_update_submit_sync( vars->update );
    assert( ret == 0 );

    printf( "Sleeping for 10 seconds...\n" );
    sleep( 10 );

    vars->update = vc_dispmanx_update_start( 10 );
    assert( vars->update );
    ret = vc_dispmanx_element_remove( vars->update, vars->element );
    assert( ret == 0 );
    ret = vc_dispmanx_update_submit_sync( vars->update );
    assert( ret == 0 );
    ret = vc_dispmanx_resource_delete( vars->resource );
    assert( ret == 0 );
    ret = vc_dispmanx_display_close( vars->display );
    assert( ret == 0 );

    return 0;
}

#ifdef __cplusplus
}
#endif

main.cpp：

#include "dispmanx.c"


#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <iostream>

using namespace cv;
using namespace std;
int main()
{
    Mat image;
    image = imread("t.png", IMREAD_COLOR);   // Read the file
    run(image.data);
}

代码应该获取一个 png 文件的地址，使用 OpenCV 库获取它的数据，并将其传递给在屏幕上显示图片的 C 程序。

我可以编译 dispmanx.c：

pi@raspberrypi:~/openCVtest.1 $ gcc -I/opt/vc/include/
    -I/opt/vc/include/interface/vcos/pthreads
    -I/opt/vc/include/interface/vmcs_host/linux
    -I/opt/vc/src/hello_pi/libs/ilclient
    -I/opt/vc/src/hello_pi/libs/vgfont
    -L/opt/vc/lib/ -L/opt/vc/src/hello_pi/libs/ilclient
    -L/opt/vc/src/hello_pi/libs/vgfont
    -c dispmanx.c
    -o dispmanx.o
    -lbrcmGLESv2 -lbrcmEGL -lopenmaxil -lbcm_host -lvcos -lvchiq_arm -lpthread -lrt -lm

但是当我尝试编译 main.cpp 时：

pi@raspberrypi:~/openCVtest.1 $ g++ -I/opt/vc/include/     -I/opt/vc/include/interface/vcos/pthreads -I/opt/vc/include/interface/vmcs_host/linux -I/opt/vc/src/hello_pi/libs/ilclient -I/opt/vc/src/hello_pi/libs/vgfont -L/opt/vc/lib/ -L/opt/vc/src/hello_pi/libs/ilclient -L/opt/vc/src/hello_pi/libs/vgfont -c main.cpp dispmanx.o  -o main.o -lbrcmGLESv2 -lbrcmEGL -lopenmaxil -lbcm_host -lvcos -lvchiq_arm -lpthread -lrt -lm               In file included from main.cpp:2:0:

dispmanx.c: 在函数 'int run(unsigned char*)': dispmanx.c:52:68: 错误：从 'int' 到 'DISPMANX_FLAGS_ALPHA_T' 的无效转换 [-fpermissive] VC_DISPMANX_ALPHA_T alpha = { DISPMANX_FLAGS_ALPHA_T | DISPMANX_FLAGS_ALPHA_FIXED_ALL_PIXELS,~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~

dispmanx.c:111:63: error: cannot convert ‘VC_IMAGE_TRANSFORM_T’ to ‘DISPMANX_TRANSFORM_T’ for argument ‘10’ to ‘DISPMANX_ELEMENT_HANDLE_T vc_dispmanx_element_add(DISPMANX_UPDATE_HANDLE_T, DISPMANX_DISPLAY_HANDLE_T, int32_t, const VC_RECT_T*, DISPMANX_RESOURCE_HANDLE_T, const VC_RECT_T*, DISPMANX_PROTECTION_T, VC_DISPMANX_ALPHA_T*, DISPMANX_CLAMP_T*, DISPMANX_TRANSFORM_T)’
                                             VC_IMAGE_ROT0 );

我已经分别测试了两个程序和它们应该的功能，但是当我尝试混合它们时，我得到了我无法理解的错误。

我是一名学生，具有初级知识水平。我究竟做错了什么？