c – OpenGL纹理格式的颜色错误

这是原始图片：

这是结果：

纹理加载代码：

void TextureManager::LoadTexture(std::string id,std::string filePath){

Texture tex;
tex.TextureId = 0;

FIBITMAP* image = FreeImage_Load(FreeImage_GetFileType(filePath.c_str(),0),filePath.c_str());


if (FreeImage_GetBPP(image) != 32) {

    image = FreeImage_ConvertTo32Bits(image);
}


FreeImage_FlipVertical(image);

tex.Width = FreeImage_GetWidth(image);
tex.Height = FreeImage_GetHeight(image);


glGenTextures(1,&tex.TextureId);
glBindTexture(GL_TEXTURE_2D,tex.TextureId);

glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_WRAP_S,GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_WRAP_T,GL_TEXTURE_MAG_FILTER,GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR);


glTexImage2D(GL_TEXTURE_2D,GL_RGBA,tex.Width,tex.Height,GL_UNSIGNED_BYTE,(void*)FreeImage_GetBits(image));

AddTextureToMap(id,tex);

FreeImage_Unload(image);
}

这是绘制它的代码：

glEnable(GL_TEXTURE_2D);
glTexEnvf(GL_TEXTURE_ENV,GL_TEXTURE_ENV_MODE,GL_MODULATE);
glBindTexture(GL_TEXTURE_2D,TextureManager.TextureMap[textureSelector].TextureId);

glBegin(GL_TRIANGLES);
glTexCoord2d(0,0);
glVertex3f(-0.75,0.75,0);//top left
glTexCoord2d(1,0);
glVertex3f(0.75,0);//top right
glTexCoord2d(0,1);
glVertex3f(-0.75,-0.75,0);//bottom left

glTexCoord2d(1,0);//top right
glTexCoord2d(1,1);
glVertex3f(0.75,0);//bottom right
glTexCoord2d(0,0);//bottom left
glEnd();
glFinish();

我很确定这是glTexImage2D中内部格式的问题,但我不确定在这种情况下我会使用哪种格式.我的问题是：它是格式,如果是,我应该使用什么;还是有另一个问题导致了这个问题？