ShaderToy Let people to learn shader of opengl es GLSL in IOS ,with object-c Also you can refer the fork from this here : https://github.com/ralph-e-boy/shadertoy you can use this code freely . to test if github can support latex When $a \ne 0$, there are two solutions to $(ax^2 + bx + c = 0)$ and they are $$ x = {-b \pm \sqrt{b^2-4ac} \over 2a} $$ $$ \lim_{n}\to{infty} $$ $$\left( \sum_{k=1}^n a_k b_k \right)^2 \leq \left( \sum_{k=1}^n a_k^2 \right) \left( \sum_{k=1}^n b_k^2 \right)$$ $$\sqrt(a) \cos (2\theta) = \cos^2 \theta - \sin^2 \theta (sum_{k=1}^n a_k b_k)^2$$ graph TD; A-->B; A-->C; B-->D; C-->D; Loading