www.pudn.com > LodFiled.rar > LOD.CPP

 
#include  
#include  
#include  
#include  
#include "bmp_load.h" 
#include "lod.h" 
 
void draw_point(int , int , int , int); 
 
int quadtree[QUAD_MAP * QUAD_MAP]; 
 
int location[3]; 
int lod_level = 8; 
 
extern LAND_TEX lt; 
 
void reset_quad_tree(void)  
{ 
	int i; 
	 
   for(i=0; i<(QUAD_MAP * QUAD_MAP); i++)  
   { 
      quadtree[i] = UNKNOWN; 
   } 
} 
 
void setup_quadtree(int x, int z, int width) 
{ 
   int width2; 
   int v1[3]; 
	 
   v1[0] = x; 
   v1[2] = z; 
	 
   width2 = width / 2; 
	 
   if((width > 1) && DISTANCE(v1, location) < width * lod_level)  
   { 
      quadtree[IX_QT(x, z)] = NODE_POINT; 
      quadtree[IX_QT(x - width2, z - width2)] = EDGE_POINT; 
      quadtree[IX_QT(x + width2, z - width2)] = EDGE_POINT; 
      quadtree[IX_QT(x - width2, z + width2)] = EDGE_POINT; 
      quadtree[IX_QT(x + width2, z + width2)] = EDGE_POINT; 
		 
      setup_quadtree(x - width2, z - width2, width2); 
      setup_quadtree(x + width2, z - width2, width2); 
      setup_quadtree(x - width2, z + width2, width2); 
      setup_quadtree(x + width2, z + width2, width2); 
   } 
   else  
   { 
      quadtree[IX_QT(x, z)] = EDGE_POINT; 
   } 
} 
 
void draw(int x, int z, int width, int direction)  
{ 
	int width2; 
 
	if(width > 1)  
	{ 
		if(width > 16)  
		{ 
			glBindTexture(GL_TEXTURE_2D, lt.texture_name[(int)((x) / 64)][(int)((z) / 64)]); 
		} 
		width2 = width / 2; 
		if(quadtree[IX_QT(x, z)] == NODE_POINT)  
		{ 
			// NORTH 
			if(quadtree[IX_QT(x - width2, z - width2)] == EDGE_POINT && 
				quadtree[IX_QT(x + width2, z - width2)] == EDGE_POINT)  
			{ 
				 
				if(quadtree[IX_QT(x, z - width*2)] == NODE_POINT || (z-width)%MAP==0)  
				{ 
					draw_point(x, z, width, NORTH_L); 
					draw_point(x, z, width, NORTH_R); 
				} 
				else  
				{ 
					draw_point(x, z, width, NORTH); 
				} 
			} 
			else if(quadtree[IX_QT(x - width2, z - width2)] == EDGE_POINT)  
			{ 
				draw_point(x, z, width, NORTH_L); 
			} 
			else if(quadtree[IX_QT(x + width2, z - width2)] == EDGE_POINT)  
			{ 
				draw_point(x, z, width, NORTH_R); 
			} 
			 
			// SOUTH 
			if(quadtree[IX_QT(x - width2, z + width2)] == EDGE_POINT && 
				quadtree[IX_QT(x + width2, z + width2)] == EDGE_POINT)  
			{ 
				 
				if(quadtree[IX_QT(x, z + width*2)] == NODE_POINT || (z+width)%MAP==0)  
				{ 
					draw_point(x, z, width, SOUTH_L); 
					draw_point(x, z, width, SOUTH_R); 
				} 
				else  
				{ 
					draw_point(x, z, width, SOUTH); 
				} 
			} 
			else if(quadtree[IX_QT(x - width2, z + width2)] == EDGE_POINT)  
			{ 
				draw_point(x, z, width, SOUTH_L); 
			} 
			else if(quadtree[IX_QT(x + width2, z + width2)] == EDGE_POINT)  
			{ 
				draw_point(x, z, width, SOUTH_R); 
			} 
			 
			// EAST 
			if(quadtree[IX_QT(x + width2, z - width2)] == EDGE_POINT && 
				quadtree[IX_QT(x + width2, z + width2)] == EDGE_POINT)  
			{ 
				 
				if(quadtree[IX_QT(x + width*2, z)] == NODE_POINT || (x+width)%MAP==0)  
				{ 
					draw_point(x, z, width, EAST_T); 
					draw_point(x, z, width, EAST_B); 
				} 
				else  
				{ 
					draw_point(x, z, width, EAST); 
				} 
			} 
			else if(quadtree[IX_QT(x + width2, z - width2)] == EDGE_POINT)  
			{ 
				draw_point(x, z, width, EAST_T); 
			} 
			else if(quadtree[IX_QT(x + width2, z + width2)] == EDGE_POINT)  
			{ 
				draw_point(x, z, width, EAST_B); 
			} 
			 
			// WEST 
			if(quadtree[IX_QT(x - width2, z - width2)] == EDGE_POINT && 
				quadtree[IX_QT(x - width2, z + width2)] == EDGE_POINT)  
			{ 
				 
				if(quadtree[IX_QT(x - width*2, z)] == NODE_POINT || (x-width)%MAP==0)  
				{ 
					draw_point(x, z, width, WEST_T); 
					draw_point(x, z, width, WEST_B); 
				} 
				else  
				{ 
					draw_point(x, z, width, WEST); 
				} 
			} 
			else if(quadtree[IX_QT(x - width2, z - width2)] == EDGE_POINT)  
			{ 
				draw_point(x, z, width, WEST_T); 
			} 
			else if(quadtree[IX_QT(x - width2, z + width2)] == EDGE_POINT)  
			{ 
				draw_point(x, z, width, WEST_B); 
			} 
		} 
		else  
		{ 
			return; 
		} 
		 
		draw(x - width2, z - width2, width2, NW); 
		draw(x + width2, z - width2, width2, NE); 
		draw(x - width2, z + width2, width2, SW); 
		draw(x + width2, z + width2, width2, SE); 
	} 
}