错误：导入函数env：emscripten_get_preloaded_image_data必须可调用

Question

这是来源（c文件）：

#include "SDL/SDL.h"
#include "SDL/SDL_image.h"

#ifndef USE_REGAL
#include "SDL/SDL_opengl.h"
#else
#include "GL/Regal.h"
#endif

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

int main(int argc, char *argv[])
{
    SDL_Surface *screen;

    // Slightly different SDL initialization
    if (SDL_Init(SDL_INIT_VIDEO) != 0)
    {
        printf("Unable to initialize SDL: %s\n", SDL_GetError());
        return 1;
    }

    SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1); // *new*

    screen = SDL_SetVideoMode(640, 480, 16, SDL_OPENGL); // *changed*
    if (!screen)
    {
        printf("Unable to set video mode: %s\n", SDL_GetError());
        return 1;
    }

#if USE_REGAL
    RegalMakeCurrent((void *)1);
#endif

    // Set the OpenGL state after creating the context with SDL_SetVideoMode

    glClearColor(0, 0, 0, 0);

    glEnable(GL_TEXTURE_2D); // Needed when we're using the fixed-function pipeline.

    glViewport(0, 0, 640, 480);

    glMatrixMode(GL_PROJECTION);
    glPushMatrix(); // just for testing
    glLoadIdentity();

    glOrtho(0, 640, 480, 0, -1, 1);

    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();

    // Load the OpenGL texture

    GLuint texture;       // Texture object handle
    SDL_Surface *surface; // Gives us the information to make the texture

    if ((surface = IMG_Load("test.png")))
    {

        // Check that the image's width is a power of 2
        if ((surface->w & (surface->w - 1)) != 0)
        {
            printf("warning: image.bmp's width is not a power of 2\n");
        }

        // Also check if the height is a power of 2
        if ((surface->h & (surface->h - 1)) != 0)
        {
            printf("warning: image.bmp's height is not a power of 2\n");
        }

        // Have OpenGL generate a texture object handle for us
        glGenTextures(1, &texture);

        // Bind the texture object
        glBindTexture(GL_TEXTURE_2D, texture);

        // Set the texture's stretching properties
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

        //SDL_LockSurface(surface);

        // Add some greyness
        memset(surface->pixels, 0x66, surface->w * surface->h);

        // Edit the texture object's image data using the information SDL_Surface gives us
        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, surface->w, surface->h, 0,
                     GL_RGBA, GL_UNSIGNED_BYTE, surface->pixels);

        //SDL_UnlockSurface(surface);
    }
    else
    {
        printf("SDL could not load image.bmp: %s\n", SDL_GetError());
        SDL_Quit();
        return 1;
    }

    // Free the SDL_Surface only if it was successfully created
    if (surface)
    {
        SDL_FreeSurface(surface);
    }

    // Clear the screen before drawing
    glClear(GL_COLOR_BUFFER_BIT);

    // Bind the texture to which subsequent calls refer to
    glBindTexture(GL_TEXTURE_2D, texture);

    glBegin(GL_QUADS);
    glTexCoord2i(0, 0);
    glVertex3f(10, 10, 0);
    glTexCoord2i(1, 0);
    glVertex3f(300, 10, 0);
    glTexCoord2i(1, 1);
    glVertex3f(300, 128, 0);
    glTexCoord2i(0, 1);
    glVertex3f(10, 128, 0);

    glTexCoord2f(0, 0.5);
    glVertex3f(410, 10, 0);
    glTexCoord2f(1, 0.5);
    glVertex3f(600, 10, 0);
    glTexCoord2f(1, 1);
    glVertex3f(630, 200, 0);
    glTexCoord2f(0.5, 1);
    glVertex3f(310, 250, 0);
    glEnd();

    // test calls to glVertex4f
    // Result should be equivalent as to glVertex3f( x/w, y/w, z/w )
    glBegin(GL_QUADS);
    glTexCoord2i(0, 0);
    glVertex4f(300, 300, 0, 2); // Square will be at (150,150) (150,250) (250,250) (250,150)
    glTexCoord2i(1, 0);
    glVertex4f(300, 500, 0, 2);
    glTexCoord2i(1, 1);
    glVertex4f(500, 500, 0, 2);
    glTexCoord2i(0, 1);
    glVertex4f(500, 300, 0, 2);
    glEnd();

    glBegin(GL_TRIANGLE_STRIP);
    glTexCoord2i(0, 0);
    glVertex3f(100, 300, 0);
    glTexCoord2i(1, 0);
    glVertex3f(300, 300, 0);
    glTexCoord2i(1, 1);
    glVertex3f(300, 400, 0);
    glTexCoord2i(0, 1);
    glVertex3f(500, 410, 0);
    glEnd();

    glDisable(GL_TEXTURE_2D);

    glColor3ub(90, 255, 255);
    glBegin(GL_QUADS);
    glVertex3f(10, 410, 0);
    glVertex3f(300, 410, 0);
    glVertex3f(300, 480, 0);
    glVertex3f(10, 470, 0);
    glEnd();

    glBegin(GL_QUADS);
    glColor3f(1.0, 0, 1.0);
    glVertex3f(410, 410, 0);
    glColor3f(0, 1.0, 0);
    glVertex3f(600, 410, 0);
    glColor3f(0, 0, 1.0);
    glVertex3f(600, 480, 0);
    glColor3f(1.0, 1.0, 1.0);
    glVertex3f(410, 470, 0);
    glEnd();

    SDL_GL_SwapBuffers();

#ifndef __EMSCRIPTEN__
    // Wait for 3 seconds to give us a chance to see the image
    SDL_Delay(3000);
#endif

    // Now we can delete the OpenGL texture and close down SDL
    glDeleteTextures(1, &texture);

    SDL_Quit();

    return 0;
}

这是我尝试使用emcc移植脚本：

  emcc sdl2-ogl/sdl_ogl.c -O2 -s USE_SDL=2 -s USE_SDL_IMAGE=2 --preload-file sdl2-ogl -s USE_REGAL=1 -DUSE_REGAL --use-preload-plugins -lSDL -lGL -o sdl2-ogl/build/test.html

运行命令后终端没有错误。

我在浏览器中遇到错误：

  

无法异步准备wasm：错误：导入功能   env：emscripten_get_preloaded_image_data必须可调用