ImGui renders image that is... unexpected

[nulliousp]

So, I have some code:

void OpenGL_FBO::CreateFBO(bool drawDefault)
{
	GLuint FBO;
	GLuint texture;

	glGenFramebuffers(1, &FBO);
	OpenGL_FBO::fbo_id = FBO;
	GLCall(glBindFramebuffer(GL_FRAMEBUFFER, OpenGL_FBO::fbo_id));

	glEnable(GL_TEXTURE_2D);

	glGenTextures(1, &texture);
	OpenGL_FBO::texture = texture;
	glBindTexture(GL_TEXTURE_2D, OpenGL_FBO::texture);

	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, OpenGL_FBO::width, OpenGL_FBO::height, 0, GL_RGB, GL_UNSIGNED_BYTE, 0);

	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

	GLCall(glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, texture, 0));

	if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE)
		ASSERT("Error");

	GLenum DrawBuffers[1] = { GL_COLOR_ATTACHMENT0 };
	glDrawBuffers(1, DrawBuffers);

	glBindFramebuffer(GL_FRAMEBUFFER, 0);

	if (drawDefault) {
		glBindFramebuffer(GL_FRAMEBUFFER, OpenGL_FBO::fbo_id);

		GLuint VAO;
		glGenVertexArrays(1, &VAO);
		glBindVertexArray(VAO);

		float vertices[] = {
			0.0f, 0.0f,
			0.0f, 0.5f,
			1.0f, 0.0f
		};

		GLuint VBO;

		glGenBuffers(1, &VBO);
		glBindBuffer(GL_ARRAY_BUFFER, VBO);
		glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);

		glActiveTexture(GL_TEXTURE0);
		glBindTexture(GL_TEXTURE_2D, 0);

		//glViewport(0, 0, OpenGL_FBO::width, OpenGL_FBO::height);
		glScissor(0, 0, OpenGL_FBO::width, OpenGL_FBO::height);
		glClearColor(1.0f, 0.1f, 0.1f, 1.0f);
		glClear(GL_COLOR_BUFFER_BIT);

		glBindFramebuffer(GL_FRAMEBUFFER, 0);

		glBindTexture(GL_TEXTURE_2D, OpenGL_FBO::texture);

		glDrawArrays(GL_TRIANGLES, 0, 3);

		glBindBuffer(GL_ARRAY_BUFFER, 0);
		glBindVertexArray(0);
		glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 0, 0);
		//glBindTexture(GL_TEXTURE_2D, 0);
	}
	glDeleteTextures(1, &texture);
	glDeleteFramebuffers(1, &FBO);
	glDeleteTextures(1, &texture);
}

that is supposed to render a triangle, but it renders:

This scares me a little but... I don't know how to fix it. It happened after I commented out glViewport(). Is this ImGui?

[nulliousp]

Sorry for making it a discussion. Go to #4611

[ocornut]

This has nothing to do with dear imgui you are not even calling imgui code there, your subject line is therefore not even a truthful representation of reality. This is not an OpenGL forum sorry.