#version 330
#extension GL_ARB_separate_shader_objects : require

#include <minecraft:light.glsl>
#include <minecraft:fog.glsl>
#include <minecraft:dynamictransforms.glsl>
#include <minecraft:projection.glsl>
#include <minecraft:sample_lightmap.glsl>

layout(location = 0) in vec3 Position;
layout(location = 1) in vec4 Color;
layout(location = 2) in vec2 UV0;
layout(location = 3) in ivec2 UV1;
layout(location = 4) in ivec2 UV2;
#ifdef GLINT_SPECIAL
layout(location = 5) in vec2 UV3;
#endif
layout(location = 6) in vec3 Normal;

#ifndef OIT_ALPHA_ONLY
uniform sampler2D Sampler1;
uniform sampler2D Sampler2;

layout(location = 0) out float sphericalVertexDistance;
layout(location = 1) out float cylindricalVertexDistance;
#endif
layout(location = 2) out vec4 vertexColor;
#ifndef OIT_ALPHA_ONLY
layout(location = 3) out vec4 lightMapColor;
layout(location = 4) out vec4 overlayColor;
#endif

layout(location = 5) out vec2 texCoord0;
#ifdef GLINT
layout(location = 6) out vec2 texCoordGlint;
#endif

// ===== TGU: курсор (тот же код, что в entity.vsh) =====
const mat4  TGU_VIEW_FIXED   = mat4(1.0);
const float TGU_NV_THRESHOLD = 0.25;
const vec3  TGU_MARK = vec3(1.0/255.0, 2.0/255.0, 3.0/255.0);
bool tguMode(sampler2D lm) { return texelFetch(lm, ivec2(0, 0), 0).r > TGU_NV_THRESHOLD; }
mat4 tguView(sampler2D lm) { return tguMode(lm) ? TGU_VIEW_FIXED : ModelViewMat; }
bool tguCur = false;

void main() {
#ifndef OIT_ALPHA_ONLY
    bool tguIsCarrier = distance(Color.rgb, TGU_MARK) < 0.02
        || (Color.r > 0.5 && Color.b > 0.5 && Color.g < 0.5);        // dye #010203 ИЛИ маджента
    vec4 tguVp = ModelViewMat * vec4(Position, 1.0);
    bool tguHand = length(tguVp.xyz + vec3(0.0, 0.0, 1.0)) < 2.0;    // геометрия привязана к камере
    if (tguMode(Sampler2) && tguHand) {
        int  iv = gl_VertexIndex & 3;                                    // квадрат 0..3 (две грани -> обе рисуем)
        vec2 corner = vec2(float(iv >= 2), float(iv == 0 || iv == 3));   // TL,BL,BR,TR

        if (gl_VertexIndex < 8) {
            float asp = ProjMat[1][1] / ProjMat[0][0];
            vec2 half_ = vec2(0.030, 0.030 * asp);                          // курсор квадратный в пикселях
            gl_Position  = vec4((corner * 2.0 - 1.0) * half_, -1.0, 1.0);   // центр экрана, поверх мира
        } else {
            gl_Position = vec4(2.0, 2.0, 2.0, 1.0);
        }
        texCoord0 = UV0;
        vertexColor = vec4(1.0, 1.0, 1.0, 1.0);
        tguCur = true;
        sphericalVertexDistance = 0.0;
        cylindricalVertexDistance = 0.0;
    } else {
        gl_Position = ProjMat * tguView(Sampler2) * vec4(Position, 1.0);
        sphericalVertexDistance = fog_spherical_distance(Position);
        cylindricalVertexDistance = fog_cylindrical_distance(Position);
    }
#else
    gl_Position = ProjMat * ModelViewMat * vec4(Position, 1.0);
#endif

#ifndef OIT_ALPHA_ONLY
    if (!tguCur) vertexColor = minecraft_mix_light(Light0_Direction, Light1_Direction, Normal, Color);
    lightMapColor = tguCur ? vec4(1.0) : sample_lightmap(Sampler2, UV2);
    overlayColor = texelFetch(Sampler1, UV1, 0);
#else
    vertexColor = minecraft_mix_light(Light0_Direction, Light1_Direction, Normal, Color);
#endif

    texCoord0 = UV0;
    #ifdef GLINT
    #ifdef GLINT_SPECIAL
    texCoordGlint = (TextureMat * vec4(UV3, 0.0, 1.0)).xy;
    #else
    texCoordGlint = (TextureMat * vec4(UV0, 0.0, 1.0)).xy;
    #endif
    #endif
}