#pragma once
#include "rtt.h"
#include "shader.h"

NS_START

class Brush
{
public:
    int id = 0;
    std::string m_name;
    uint16_t m_tex_id = 0;
    glm::vec4 m_tip_color{1, 0, 0, 1};
    float m_tip_size = 0;
    float m_tip_spacing = 0;
    float m_tip_flow = 0;
    float m_tip_opacity = 0;
    float m_tip_angle = 0;
    float m_tip_stencil = 0;
    float m_tip_wet = 0;
    float m_tip_noise = 0;
    bool  m_tip_angle_follow = false;
    bool  m_tip_flow_pressure = false;
    bool  m_tip_size_pressure = false;
    float m_jitter_scale = 0;
    float m_jitter_angle = 0;
    float m_jitter_spread = 0;
    float m_jitter_flow = 0;
    int m_blend_mode = 0;
};

struct StrokeSample
{
    glm::vec2 pos = { 0, 0 };
    glm::vec2 origin = { 0,0 };
    float size = 0;
    float flow = 0;
    float angle = 0;
};

class BrushMesh
{
public:
    GLuint buffers[3]{ 0 };
    GLuint vao{ 0 };
    struct vertex_t { glm::vec4 pos; glm::vec2 uvs; };
    struct instance_t { glm::mat4 mvp; float flow; };
    int loc_flow = 0;
    int loc_mvp = 0;
    
    bool create();
    void draw(const std::vector<StrokeSample>& samples, const glm::mat4& proj);
};

class Stroke
{
public:
    struct Keypoint
    {
        glm::vec2 pos = { 0, 0 };
        float pressure = 0;
        float dist = 0;
    };
    struct Camera
    {
        glm::vec2 rot = { 0, 0 };
        float fov = 0;
    };
    int m_layer = 0;
    float m_curve = 0;
    float m_dist = 0;
    float m_step = 0;
    Camera m_camera;
    ui::Brush m_brush;
    cbuffer<float, 3> m_curve_angles;
    StrokeSample m_prev_sample;
    std::vector<Keypoint> m_keypoints;
    std::vector<StrokeSample> m_samples;
    int m_last_kp;
    std::minstd_rand prng;
    void start(const ui::Brush& brush);
    void add_point(glm::vec2 pos, float pressure);
    void reset(bool clear_keypoints = false);
    bool has_sample();
    std::vector<StrokeSample> compute_samples();
    StrokeSample randomize_sample(const glm::vec2& pos, float pressure, float curve_angle);
};

NS_END