virtualx-engine/scene/2d/line_builder.h

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/*  line_builder.h                                                       */
/*************************************************************************/
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#ifndef LINE_BUILDER_H
#define LINE_BUILDER_H

#include "core/math/color.h"
#include "core/math/vector2.h"
#include "line_2d.h"
#include "scene/resources/gradient.h"

class LineBuilder {
public:
	// TODO Move in a struct and reference it
	// Input
	Vector<Vector2> points;
	Line2D::LineJointMode joint_mode = Line2D::LINE_JOINT_SHARP;
	Line2D::LineCapMode begin_cap_mode = Line2D::LINE_CAP_NONE;
	Line2D::LineCapMode end_cap_mode = Line2D::LINE_CAP_NONE;
	float width = 10.0;
	Curve *curve = nullptr;
	Color default_color = Color(0.4, 0.5, 1);
	Gradient *gradient = nullptr;
	Line2D::LineTextureMode texture_mode = Line2D::LineTextureMode::LINE_TEXTURE_NONE;
	float sharp_limit = 2.f;
	int round_precision = 8;
	float tile_aspect = 1.f; // w/h
	// TODO offset_joints option (offers alternative implementation of round joints)

	// TODO Move in a struct and reference it
	// Output
	Vector<Vector2> vertices;
	Vector<Color> colors;
	Vector<Vector2> uvs;
	Vector<int> indices;

	LineBuilder();

	void build();
	void clear_output();

private:
	enum Orientation {
		UP = 0,
		DOWN = 1
	};

	// Triangle-strip methods
	void strip_begin(Vector2 up, Vector2 down, Color color, float uvx);
	void strip_new_quad(Vector2 up, Vector2 down, Color color, float uvx);
	void strip_add_quad(Vector2 up, Vector2 down, Color color, float uvx);
	void strip_add_tri(Vector2 up, Orientation orientation);
	void strip_add_arc(Vector2 center, float angle_delta, Orientation orientation);

	void new_arc(Vector2 center, Vector2 vbegin, float angle_delta, Color color, Rect2 uv_rect);

private:
	bool _interpolate_color = false;
	int _last_index[2] = {}; // Index of last up and down vertices of the strip
};

#endif // LINE_BUILDER_H