我可以在SOIL / OpenGL中正常加载纹理。没有错误,一切正常:
// this is inside my texture loading code in my texture class
// that i normally use for loading textures
image = SOIL_load_OGL_texture
(
file,
SOIL_LOAD_AUTO,
SOIL_CREATE_NEW_ID,
NULL
);
但是,使用相同的代码并从std :: thread调用它,在image = SOIL_load_OGL_texture
行我得到未处理的异常Integer Division by Zero
:
void loadMe() {
Texture* abc = new Texture("res/img/office.png");
}
void loadStuff() {
Texture* loading = new Texture("res/img/head.png"); // < always works
loadMe() // < always works
std::thread textures(loadMe); // < always "integer division by zero"
这是我的Texture类中的一些相关代码:
// inside the class
private:
GLint w, h;
GLuint image;
// loading the texture (called by constructor if filename is given)
void Texture::loadImage(const char* file)
{
image = SOIL_load_OGL_texture
(
file,
SOIL_LOAD_AUTO,
SOIL_CREATE_NEW_ID,
NULL
);
glEnable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, image);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
glGetTexLevelParameteriv(GL_TEXTURE_2D, 0, GL_TEXTURE_WIDTH, &w);
glGetTexLevelParameteriv(GL_TEXTURE_2D, 0, GL_TEXTURE_HEIGHT, &h);
glBindTexture(GL_TEXTURE_2D, 0);
if (image <= 0)
std::cout << file << " failed to load!\n";
else
std::cout << file << " loaded.\n";
glDisable(GL_TEXTURE_2D);
}
它在image = SOIL_load_OGL_texture
完全引发了异常,当我进入调试器时,我会看到w = -816294792
和w = -816294792
之类的内容,但我猜这只是意味着它没有设置,因为它还显示在调试器中加载其他纹理。
此外,代码的SOIL_load_OGL_texture部分可以在Texture类之外自行运行,即使在std :: thread中也是如此。
知道这里发生了什么吗?
答案 0 :(得分:0)
这是你如何做到的。请注意,正如其他人在评论中提到的那样,每个使用GL的线程都需要保持上下文的最新状态。这意味着实际上不能在多个线程中进行GL API调用而不使一个线程成为GL上下文的所有者。因此,如果意图分离Image加载开销,建议使用单独线程中的库将图像文件加载到缓冲区中,然后将该缓冲区用于主线程中的glTexImage2D。加载图像后,可以显示虚拟纹理。
我尝试检查你所使用的平台(见上面的评论),因为我没有看到回复,我在下面假设Linux。
/* Regular GL context creation foo */
/* Regular attribute, uniform, shader creation foo */
/* Create a thread that does loading with SOIL in function SOIL_loader */
std::thread textureloader(SOIL_loader);
/* Wait for loader thread to finish,
thus defeating the purpose of a thread. Ideally,
only the image file read/decode should happen in separate thread */
textureloader.join();
/* Make the GL context current back again in the main thread
for other actions */
glfwMakeContextCurrent((GLFWwindow*)window);
/* Some other foo */
==
这是加载程序线程函数:
void SOIL_loader()
{
glfwMakeContextCurrent((GLFWwindow*)window);
SOIL_load_OGL_texture
(
"./img_test.png",
SOIL_LOAD_AUTO,
SOIL_CREATE_NEW_ID /* or passed ID */,
NULL
);
GL_CHECK(SOIL);
}
在Ubuntu 14.04,Mesa和glfw3上进行了测试。