为什么我的OpenGL纹理是黑色的(在亲爱的ImGUI中)?

xkrw2x1b  于 2022-11-23  发布在  其他
关注(0)|答案(2)|浏览(332)

在OpenGL 4.6中,我(尝试)创建并初始化纯色纹理,如下所示:

glCreateTextures(GL_TEXTURE_2D, 1, &_textureHandle);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glPixelStorei(GL_UNPACK_ROW_LENGTH, 0); // This doesn't change the outcome
std::vector<unsigned char> data(3 * WIDTH * HEIGHT, static_cast<unsigned char>(200));
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, WIDTH, HEIGHT, 0, GL_RGB, GL_UNSIGNED_BYTE, data.data());

然后我在Dear ImGUI中使用了如下的纹理:

ImGui::Image((void*)(intptr_t) _textureHandle, ImVec2(WIDTH, HEIGHT));

但是,这只是显示黑色纹理。
我还尝试了一种不同的初始化方式(没有效果):

unsigned char* data = new unsigned char[3 * WIDTH * HEIGHT];
for (unsigned int i = 0; i < (int)(WIDTH * HEIGHT); i++) {
    data[i * 3] = (unsigned char)255;
    data[i * 3 + 1] = (unsigned char)50;
    data[i * 3 + 2] = (unsigned char)170;
}
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, WIDTH, HEIGHT, 0, GL_RGB, GL_UNSIGNED_BYTE, data);

有人知道我做错了什么吗?

swvgeqrz

swvgeqrz1#

使用OpenGL 4.5 DSA创建纹理,但未使用DSA设置纹理参数和图像。
您必须使用glTextureParameterglTextureStorage2DglTextureSubImage2D,而不是glTexParameterglTexImage2D

glCreateTextures(GL_TEXTURE_2D, 1, &_textureHandle);
glTextureParameteri(_textureHandle, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTextureParameteri(_textureHandle, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTextureParameteri(_textureHandle, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
glTextureParameteri(_textureHandle, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
std::vector<unsigned char> data(3 * WIDTH * HEIGHT, static_cast<unsigned char>(200));
glTextureStorage2D(_textureHandle, 1, GL_RGB8, WIDTH, HEIGHT);
glTextureSubImage2D(_textureHandle, 0, 0, 0, WIDTH, HEIGHT, GL_RGB, GL_UNSIGNED_BYTE, data.data());
bbuxkriu

bbuxkriu2#

如果不生成mipmaps(使用glGenerateMipmap),则必须将GL_TEXTURE_MIN_FILTER设置为非Mipmap过滤器。如果不将缩小函数更改为GL_NEARESTGL_LINEAR,则纹理将为“Mipmap不完整”。
Eiter生成mipmap:

glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, WIDTH, HEIGHT, 0, GL_RGB, GL_UNSIGNED_BYTE, data.data());
glGenerateMipmap(GL_TEXTURE_2D);

或者使用GL_LINEAR作为缩小函数:

glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP);

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