uniform sampler2D top_tex_in; uniform sampler2D bottom_tex_in; uniform vec2 resolution_in; in vec2 ove_texcoord; out vec4 frag_color; void main() { float y_pixel = floor(ove_texcoord.y * resolution_in.y); if (mod(y_pixel, 2.0) == 0.0) { frag_color = texture(top_tex_in, ove_texcoord); } else { frag_color = texture(bottom_tex_in, ove_texcoord); } }