demo/snake/shader/player.glsl

layout(location = 0) out vec4 diffuse;
in vec2 uvcoord;

uniform sampler2D map_albedo;
uniform sampler2D map_color;
uniform vec4 color;

void main(void) {
    // TODO: use greyscale texture instead
    vec4 color_map_pixel = texture(map_color, uvcoord);
    if (color_map_pixel.a > 0) {
        diffuse = color * color_map_pixel * texture(map_albedo, uvcoord);
    } else {
        diffuse = texture(map_albedo, uvcoord);
    }
}