@header const m = @import("math")
@ctype mat4 m.Mat4

/* main vertex shader */
@vs vs
in vec2 position;
in vec2 texcoord0;
in vec4 color0;
out vec4 color;
out vec4 uv;

layout(binding = 0) uniform vs_params {
    mat4 view;
    mat4 projection;
};

void main() {
    gl_Position = projection * view * vec4(position, 0, 1);
    color = color0;
    uv = vec4(texcoord0, 0.0, 1.0);
}
@end

/* main fragment shader */
@fs fs
layout(binding=0) uniform texture2D tex;
layout(binding=0) uniform sampler smp;
in vec4 color;
in vec4 uv;
out vec4 frag_color;

layout(binding = 1) uniform fs_params {
    // Textures modes:
    // 0 - rgba8
    // 1 - r8 - use red channel as opacity, used for fonts.
    int texture_mode;
};

void main() {
    vec4 tex_color = texture(sampler2D(tex, smp), uv.xy);
    if (texture_mode == 0) {
        frag_color = tex_color * color;
    } else if (texture_mode == 1) {
        frag_color = vec4(1, 1, 1, tex_color.r) * color;
    }
}
@end

/* main shader program */
@program main vs fs