/*
- * Copyright (C) 2009 Andy Spencer <spenceal@rose-hulman.edu>
+ * Copyright (C) 2009-2010 Andy Spencer <andy753421@gmail.com>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
typedef struct _RoamTriangle RoamTriangle;
typedef struct _RoamDiamond RoamDiamond;
typedef struct _RoamSphere RoamSphere;
+/**
+ * RoamHeightFunc:
+ * @lat: the latitude
+ * @lon: the longitude
+ * @user_data: user data passed to the function
+ *
+ * See #GisHeightFunc
+ *
+ * Returns: the elevation
+ */
typedef gdouble (*RoamHeightFunc)(gdouble lat, gdouble lon, gpointer user_data);
/* Misc */
+/**
+ * RoamView:
+ * @model: model view matrix
+ * @proj: projection matrix
+ * @view: viewport matrix
+ * @version: version
+ *
+ * Stores projection matrices
+ */
struct _RoamView {
gdouble model[16];
gdouble proj[16];
/*************
* RoamPoint *
*************/
+/**
+ * RoamPoint:
+ *
+ * Points are used as vertices for triangles. A single point my be shared among
+ * several triangles in order to conceive space and avoid recalculating
+ * projections. Points also store a lot of cached data. The normal vertex normal
+ * is the averaged surface normal of each associated triangle.
+ */
struct _RoamPoint {
- gdouble x,y,z; // Model coordinates
- gdouble px,py,pz; // Projected coordinates
- gint pversion; // Version of cached projection
+ /*< private >*/
+ gdouble x, y, z; /* Model coordinates */
+ gdouble px, py, pz; /* Projected coordinates */
+ gint pversion; /* Version of cached projection */
- gint tris; // Associated triangles
- gdouble norm[3]; // Vertex normal
+ gint tris; /* Count of associated triangles */
+ gdouble norm[3]; /* Vertex normal */
/* For get_intersect */
gdouble lat, lon, elev;
RoamHeightFunc height_func;
gpointer height_data;
};
-RoamPoint *roam_point_new(double x, double y, double z);
+RoamPoint *roam_point_new(double lat, double lon, double elev);
void roam_point_add_triangle(RoamPoint *point, RoamTriangle *triangle);
void roam_point_remove_triangle(RoamPoint *point, RoamTriangle *triangle);
void roam_point_update_height(RoamPoint *point);
-void roam_point_update_projection(RoamPoint *point, RoamSphere *sphere);
+void roam_point_update_projection(RoamPoint *point, RoamView *view);
/****************
* RoamTriangle *
****************/
+/**
+ * RoamTriangle:
+ *
+ * Triangles are one of the key datatypes in ROAM. The surface is made up of
+ * triangles. Each triangle has an associated "error". When the surface is being
+ * updated after the view changes, each triangles error is updated. Afterwards
+ * the triangles with the most error are split int to triangles, each with a
+ * lower error than the original.
+ *
+ * Triangles store a lot of data about their location in the mesh so that they
+ * can be split and merged (unsplit) without having to recreate the mesh.
+ */
struct _RoamTriangle {
+ /*< private >*/
+ /* Left, middle and right vertices */
struct { RoamPoint *l,*m,*r; } p;
+
+ /* Left, base, and right neighbor triangles */
struct { RoamTriangle *l,*b,*r; } t;
- RoamPoint *split;
- RoamDiamond *parent;
- double norm[3];
- double error;
+
+ RoamPoint *split; /* Split point */
+ RoamDiamond *parent; /* Parent diamond */
+ RoamTriangle *kids[2]; /* Higher-res triangles */
+ double norm[3]; /* Surface normal */
+ double error; /* Screen space error */
GPQueueHandle handle;
/* For get_intersect */
struct { gdouble n,s,e,w; } edge;
- RoamTriangle *kids[2];
};
-RoamTriangle *roam_triangle_new(RoamPoint *l, RoamPoint *m, RoamPoint *r);
+RoamTriangle *roam_triangle_new(RoamPoint *l, RoamPoint *m, RoamPoint *r,
+ RoamDiamond *parent);
+void roam_triangle_free(RoamTriangle *triangle);
void roam_triangle_add(RoamTriangle *triangle,
RoamTriangle *left, RoamTriangle *base, RoamTriangle *right,
RoamSphere *sphere);
void roam_triangle_remove(RoamTriangle *triangle, RoamSphere *sphere);
void roam_triangle_update_errors(RoamTriangle *triangle, RoamSphere *sphere);
void roam_triangle_split(RoamTriangle *triangle, RoamSphere *sphere);
+void roam_triangle_draw(RoamTriangle *triangle);
void roam_triangle_draw_normal(RoamTriangle *triangle);
/***************
* RoamDiamond *
***************/
+/**
+ * RoamDiamond:
+ *
+ * When two adjacent triangles are split, they, along with the four new child
+ * triangles, are added to a diamond which keeps track of them.
+ *
+ * Like triangles, diamond have an error associated with it. However, when a
+ * diamonds error is small enough it is "merged". That is, the diamond along
+ * with the child triangles is removed and the original two triangles triangles
+ * are added back into the mesh.
+ */
struct _RoamDiamond {
- RoamTriangle *kids[4];
- RoamTriangle *parents[2];
- double error;
- gboolean active;
+ /*< private >*/
+ RoamTriangle *parents[2]; /* Parent triangles */
+ double error; /* Screen space error */
+ gboolean active; /* For internal use */
GPQueueHandle handle;
};
-RoamDiamond *roam_diamond_new(
- RoamTriangle *parent0, RoamTriangle *parent1,
- RoamTriangle *kid0, RoamTriangle *kid1,
- RoamTriangle *kid2, RoamTriangle *kid3);
+RoamDiamond *roam_diamond_new(RoamTriangle *parent0, RoamTriangle *parent1);
void roam_diamond_add(RoamDiamond *diamond, RoamSphere *sphere);
void roam_diamond_remove(RoamDiamond *diamond, RoamSphere *sphere);
void roam_diamond_merge(RoamDiamond *diamond, RoamSphere *sphere);
-void roam_diamond_update_errors(RoamDiamond *self, RoamSphere *sphere);
+void roam_diamond_update_errors(RoamDiamond *diamond, RoamSphere *sphere);
/**************
* RoamSphere *
**************/
+/**
+ * RoamSphere:
+ *
+ * The sphere keeps track of the triangles and diamonds in the mesh.
+ *
+ * Originally the sphere consists of only 8 triangles forming a octahedron.
+ * These triangles are quickly split to create a smoother sphere.
+ */
struct _RoamSphere {
- GPQueue *triangles;
- GPQueue *diamonds;
- RoamView *view;
- gint polys;
+ /*< private >*/
+ GPQueue *triangles; /* List of triangles */
+ GPQueue *diamonds; /* List of diamonds */
+ RoamView *view; /* Current projection */
+ gint polys; /* Polygon count */
/* For get_intersect */
- RoamTriangle *roots[8];
+ RoamTriangle *roots[8]; /* Original 8 triangles */
};
RoamSphere *roam_sphere_new();
void roam_sphere_update_view(RoamSphere *sphere);
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