# Copyright 2004-2021 Tom Rothamel <pytom@bishoujo.us>
#
# Permission is hereby granted, free of charge, to any person
# obtaining a copy of this software and associated documentation files
# (the "Software"), to deal in the Software without restriction,
# including without limitation the rights to use, copy, modify, merge,
# publish, distribute, sublicense, and/or sell copies of the Software,
# and to permit persons to whom the Software is furnished to do so,
# subject to the following conditions:
#
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

init python:

    renpy.register_shader("renpy.geometry", variables="""
        uniform mat4 u_transform;
        attribute vec4 a_position;
    """, vertex_100="""
        gl_Position = u_transform * a_position;
    """)

    renpy.register_shader("renpy.texture", variables="""
        uniform float u_lod_bias;
        uniform sampler2D tex0;
        attribute vec2 a_tex_coord;
        varying vec2 v_tex_coord;
    """, vertex_200="""
        v_tex_coord = a_tex_coord;
    """, fragment_200="""
        gl_FragColor = texture2D(tex0, v_tex_coord.xy, u_lod_bias);
    """)

    renpy.register_shader("renpy.blur", variables="""
        uniform sampler2D tex0;
        attribute vec2 a_tex_coord;
        varying vec2 v_tex_coord;
        uniform float u_renpy_blur_log2;
    """, vertex_200="""
        v_tex_coord = a_tex_coord;
    """, fragment_200="""
        gl_FragColor = vec4(0.);
        float renpy_blur_norm = 0.;

        for (float i = -5.; i < 1.; i += 1.) {
            float renpy_blur_weight = exp(-0.5 * pow(u_renpy_blur_log2 - i, 2.));
            renpy_blur_norm += renpy_blur_weight;
        }

        gl_FragColor += renpy_blur_norm * texture2D(tex0, v_tex_coord.xy, 0.);

        for (float i = 1.; i < 14.; i += 1.) {

            if (i >= u_renpy_blur_log2 + 5.) {
                break;
            }

            float renpy_blur_weight = exp(-0.5 * pow(u_renpy_blur_log2 - i, 2.));
            gl_FragColor += renpy_blur_weight * texture2D(tex0, v_tex_coord.xy, i);
            renpy_blur_norm += renpy_blur_weight;
        }

        gl_FragColor /= renpy_blur_norm;
   """)

    renpy.register_shader("renpy.solid", variables="""
        uniform vec4 u_renpy_solid_color;
    """, fragment_200="""
        gl_FragColor = u_renpy_solid_color;
    """)

    renpy.register_shader("renpy.dissolve", variables="""
        uniform float u_lod_bias;
        uniform sampler2D tex0;
        uniform sampler2D tex1;
        uniform float u_renpy_dissolve;
        attribute vec2 a_tex_coord;
        varying vec2 v_tex_coord;
    """, vertex_200="""
        v_tex_coord = a_tex_coord;
    """, fragment_200="""
        vec4 color0 = texture2D(tex0, v_tex_coord.st, u_lod_bias);
        vec4 color1 = texture2D(tex1, v_tex_coord.st, u_lod_bias);

        gl_FragColor = mix(color0, color1, u_renpy_dissolve);
    """)

    renpy.register_shader("renpy.imagedissolve", variables="""
        uniform float u_lod_bias;
        uniform sampler2D tex0;
        uniform sampler2D tex1;
        uniform sampler2D tex2;
        uniform float u_renpy_dissolve_offset;
        uniform float u_renpy_dissolve_multiplier;
        attribute vec2 a_tex_coord;
        varying vec2 v_tex_coord;
    """, vertex_200="""
        v_tex_coord = a_tex_coord;
    """, fragment_200="""
        vec4 color0 = texture2D(tex0, v_tex_coord.st, u_lod_bias);
        vec4 color1 = texture2D(tex1, v_tex_coord.st, u_lod_bias);
        vec4 color2 = texture2D(tex2, v_tex_coord.st, u_lod_bias);

        float a = clamp((color0.a + u_renpy_dissolve_offset) * u_renpy_dissolve_multiplier, 0.0, 1.0);
        gl_FragColor = mix(color1, color2, a);
    """)


    renpy.register_shader("renpy.matrixcolor", variables="""
        uniform mat4 u_renpy_matrixcolor;
    """, fragment_400="""
        gl_FragColor = u_renpy_matrixcolor * gl_FragColor;
    """)

    renpy.register_shader("renpy.alpha", variables="""
        uniform float u_renpy_alpha;
        uniform float u_renpy_over;
    """, fragment_500="""
        gl_FragColor = gl_FragColor * vec4(u_renpy_alpha, u_renpy_alpha, u_renpy_alpha, u_renpy_alpha * u_renpy_over);
    """)

    renpy.register_shader("renpy.ftl", variables="""
        attribute vec4 a_position;
        attribute vec2 a_tex_coord;
        varying vec2 v_tex_coord;
        uniform sampler2D tex0;
    """, vertex_100="""
        v_tex_coord = a_tex_coord;
        gl_Position = a_position;
    """, fragment_100="""
        gl_FragColor = texture2D(tex0, v_tex_coord.xy, -1.0);
    """)

init python hide:

    def multiply(old, new):
        return old * new

    config.merge_uniforms["u_renpy_alpha"] = multiply
    config.merge_uniforms["u_renpy_over"] = multiply
    config.merge_uniforms["u_renpy_matrixcolor"] = multiply
