shader.fs

#version 330 core

out vec4 FragColor;

in vec3 ourColor;
in vec2 TexCoord;

uniform sampler2D texture1;
uniform sampler2D texture2;
uniform float zoom;

void main()
{
    vec2 smileCoord = vec2(-TexCoord.x, TexCoord.y);
    FragColor = mix(texture(texture1, TexCoord), texture(texture2, smileCoord), zoom);
}