src/gldata.h

#ifndef LDFORGE_GLDATA_H
#define LDFORGE_GLDATA_H

#include "types.h"
#include "gldraw.h"
#include <QMap>
#include <QRgb>

class QColor;
class LDTriangle;
class LDFile;

/* =============================================================================
 * -----------------------------------------------------------------------------
 * VertexCompiler
 *
 * This class manages vertex arrays for the GL renderer, compiling vertices into
 * VAO-readable triangles which can be requested with getMergedBuffer.
 *
 * There are 5 main array types:
 * - the normal polygon array, for triangles
 * - edge line array, for lines
 * - BFC array, this is the same as the normal polygon array except that the
 * -     polygons are listed twice, once normally and green and once reversed
 * -     and red, this allows BFC red/green view.
 * - Picking array, this is the samea s the normal polygon array except the
 * -     polygons are compiled with their index color, this way the picking
 * -     method is capable of determining which object was selected by pixel
 * -     color.
 * - Edge line picking array, the pick array version of the edge line array.
 *
 * There are also these same 5 arrays for every LDObject compiled. The main
 * arrays are generated on demand from the ones in the current file's
 * LDObjects and stored in cache for faster rendering.
 *
 * The nested Array class contains a vector-like buffer of the Vertex structs,
 * these structs are the VAOs that get passed to the renderer.
 */

class VertexCompiler {
public:
	enum ColorType {
		Normal,
		BFCFront,
		BFCBack,
		PickColor,
	};
	
	struct CompiledTriangle {
		vertex    verts[3];
		uint8     numVerts;    // 2 if a line
		QRgb      rgb;         // Color of this poly normally
		QRgb      pickrgb;     // Color of this poly while picking
		bool      isCondLine;  // Is this a conditional line?
		LDObject* obj;         // Pointer to the object this poly represents
	};
	
	struct Vertex {
		float x, y, z;
		uint32 color;
		float pad[4];
	};
	
	class Array {
	public:
		typedef int32 Size;
		
		Array();
		Array (const Array& other) = delete;
		~Array();
		
		void clear();
		void merge (Array* other);
		void resizeToFit (Size newSize);
		const Size& allocatedSize() const;
		Size writtenSize() const;
		const Vertex* data() const;
		void write (const VertexCompiler::Vertex& f);
		Array& operator= (const Array& other) = delete;
		
	private:
		Vertex* m_data;
		Vertex* m_ptr;
		Size m_size;
	};
	
	VertexCompiler();
	~VertexCompiler();
	void setFile (LDFile* file);
	void compileFile();
	void forgetObject (LDObject* obj);
	void initObject (LDObject* obj);
	const Array* getMergedBuffer (GL::VAOType type);
	QColor getObjectColor (LDObject* obj, ColorType list) const;
	void needMerge();
	void stageForCompilation (LDObject* obj);
	
	static uint32 getColorRGB (QColor& color);
	
private:
	void compilePolygon (LDObject* drawobj, LDObject* trueobj, List<CompiledTriangle>& data);
	void compileObject (LDObject* obj);
	void compileSubObject (LDObject* obj, LDObject* topobj, List<CompiledTriangle>& data);
	Array* postprocess (const CompiledTriangle& i, GL::VAOType type);
	
	QMap<LDObject*, Array*> m_objArrays;
	QMap<LDFile*, Array*> m_fileCache;
	Array m_mainArrays[GL::NumArrays];
	LDFile* m_file;
	bool m_changed[GL::NumArrays];
	List<LDObject*> m_staged;
};

extern VertexCompiler g_vertexCompiler;

#endif // LDFORGE_GLDATA_H