joeylib3d/j3d/j3d.h

/*
 *  JoeyLib 3D
 *  Copyright (C) 2019 Scott Duensing <scott@kangaroopunch.com>
 *
 *  This software is provided 'as-is', without any express or implied
 *  warranty.  In no event will the authors be held liable for any damages
 *  arising from the use of this software.
 *
 *  Permission is granted to anyone to use this software for any purpose,
 *  including commercial applications, and to alter it and redistribute it
 *  freely, subject to the following restrictions:
 *
 *  1. The origin of this software must not be misrepresented; you must not
 *     claim that you wrote the original software. If you use this software
 *     in a product, an acknowledgment in the product documentation would be
 *     appreciated but is not required.
 *  2. Altered source versions must be plainly marked as such, and must not be
 *     misrepresented as being the original software.
 *  3. This notice may not be removed or altered from any source distribution.
*/


#ifndef H_J3D_
#define H_J3D_


#include "joey.h"


//***TODO***   verticies is vertices


typedef float j3Matrix4x4T[4][4];

typedef struct {
	jint16 x;
	jint16 y;
	jint16 z;
} j3FacingT;

typedef struct {
	float x;
	float y;
	float z;
} j3VertexT, j3Vector3DT;

typedef struct {
	j3VertexT local;     // Original vertex positions
	j3VertexT world;     // After rotation, scale, translation (in that order)
	j3VertexT camera;    // Camera space
} j3CoordinatesT;

typedef struct {
	jint16  color;         // Assigned color of this face
	jint16  shade;         // Color of this face after lighting
	bool    lit;           // Do we care about lighting?
	bool    visible;       // Can we see this triangle?
	bool    twoSided;      // Are both sides visible?
	float   normalLength;  // Magnatude of surface normal
	juint16 index[3];      // We do this instead of just a typedef so it works with stretch_buffer
} j3TriangleT;

typedef struct {
	juint16         vertexCount;    // How many verticies are in the list
	juint16         triangleCount;  // How many triangles are in the list
	j3CoordinatesT *verticies;      // List of verticies as loaded from disk (more v1, v2, v3 than x, y, z)
	j3TriangleT    *triangles;      // Triangles built from vertex list
	j3VertexT       position;       // Position of object in world
	j3VertexT       rotation;       // Rotation of object in world
	j3VertexT       scale;          // Scale of object in world
} j3ObjectT;

typedef struct {
	juint16    objectCount;
	j3ObjectT *objects;
} j3WorldT;


#define jtCameraSetClippingBounds(x1, y1, x2, y2)  \
	clipMinX = (x1);  j3MathCheckBounds(clipMinX, 0, 319);  \
	clipMinY = (y1);  j3MathCheckBounds(clipMiny, 0, 199);  \
	clipMaxX = (x2);  j3MathCheckBounds(clipMaxX, 0, 319);  \
	clipMaxY = (y2);  j3MathCheckBounds(clipMaxy, 0, 199)

#define j3MathCheckBounds(value, min, max)  \
	if (value < (min)) value = (min);  \
	if (value > (max)) value = (max)

#define j3MathWrapBounds(value, min, max)  \
	if (value < (min)) value += (max);  \
	if (value > (max)) value -= (max)

#define j3ObjectMove(ob, px, py, pz) \
	ob.position.x += (px);  \
	ob.position.y += (py);  \
	ob.position.z += (pz)

#define j3ObjectMoveTo(ob, px, py, pz)  \
	ob.position.x = (px);   \
	ob.position.y = (py);   \
	ob.position.z = (pz)

#define j3ObjectRotate(ob, px, py, pz) \
	ob.rotation.x += (px);  j3MathWrapBounds(ob.rotation.x, 0, 360);  \
	ob.rotation.y += (py);  j3MathWrapBounds(ob.rotation.y, 0, 360);  \
	ob.rotation.z += (pz);  j3MathWrapBounds(ob.rotation.z, 0, 360)

#define j3ObjectRotateTo(ob, px, py, pz) \
	ob.rotation.x = (px);  j3MathWrapBounds(ob.rotation.x, 0, 360);  \
	ob.rotation.y = (py);  j3MathWrapBounds(ob.rotation.y, 0, 360);  \
	ob.rotation.z = (pz);  j3MathWrapBounds(ob.rotation.z, 0, 360)

#define j3ObjectScale(ob, px, py, pz)  \
	ob.scale.x += (px);  \
	ob.scale.y += (py);  \
	ob.scale.z += (pz)

#define j3ObjectScaleTo(ob, px, py, pz)  \
	ob.scale.x = (px);  \
	ob.scale.y = (py);  \
	ob.scale.z = (pz)


// Syntatic sugar
#define j3DrawSolid(o)                 _j3DrawSolid(&(o))
#define j3DrawWireframe(o)             _j3DrawWireframe(&(o))
#define j3ObjectReset(o)               _j3ObjectReset(&(o))
#define j3ObjectUpdate(o)              _j3ObjectUpdate(&(o))
#define j3WorldFree(w)                 _j3WorldFree((j3WorldT **)&(w))
#define j3WorldLoad(w, f)              _j3WorldLoad((j3WorldT **)&(w), (f))


// Prototypes
void  j3DrawTriangle2D(jint16 x1, jint16 y1, jint16 x2,jint16 y2, jint16 x3, jint16 y3, jint16 color);
void  j3MathCrossProduct3D(j3Vector3DT *u, j3Vector3DT *v, j3Vector3DT *normal);
float j3MathDotProduct3D(j3Vector3DT *u, j3Vector3DT *v);
void  j3MathMatrix4x4Identity(j3Matrix4x4T result);
void  j3MathMatrix4x4Mult(j3Matrix4x4T a, j3Matrix4x4T b, j3Matrix4x4T result);
void  j3MathMakeVector3D(j3VertexT *init, j3VertexT *term, j3Vector3DT *result);
float j3MathVectorMagnatude3D(j3Vector3DT *v);
void  j3UtilShutdown(void);
void  j3UtilStartup(void);


// Private Prototypes
void _j3DrawSolid(j3ObjectT *o);
void _j3DrawTriangleBottom(jint16 x1, jint16 y1, jint16 x2,jint16 y2, jint16 x3, jint16 y3);
void _j3DrawTriangleTop(jint16 x1, jint16 y1, jint16 x2,jint16 y2, jint16 x3, jint16 y3);
void _j3DrawWireframePair(j3ObjectT *o, juint16 v1, juint16 v2);
void _j3DrawWireframe(j3ObjectT *o);
void _j3ObjectReset(j3ObjectT *o);
void _j3ObjectUpdate(j3ObjectT *o);
bool _j3UtilClipLine(jint16 *x1, jint16 *y1, jint16 *x2, jint16 *y2);
void _j3WorldFree(j3WorldT **world);
bool _j3WorldLoad(j3WorldT **world, char *file);


#endif // H_J3D_