medfall

commit 5f8da39e52c2123926e38a2df10f3fb5814b0701
parent 7f660d353b08b724b486feb2d5da6e676b690d14
Author: Michael Savage <mikejsavage@gmail.com>
Date:   Fri, 10 Nov 2017 21:47:26 +0200

Don't descend into quadtree nodes that are too far away in segment_vs_quadtree

Diffstat:
heightmap.cc
 | 
19
+++++++++----------
heightmap.h
 | 
4
+++-

2 files changed, 12 insertions(+), 11 deletions(-)
diff --git a/heightmap.cc b/heightmap.cc
@@ -1,5 +1,4 @@
 #include <stdio.h>
-#include <float.h>
 
 #include "intrinsics.h"
 #include "linear_algebra.h"
@@ -175,7 +174,7 @@ static void sort4( int * indices, float * elems ) {
 
 static bool ray_vs_quadtree_node(
 	const QuadTree & qt, size_t node_idx, MinMaxu32 aabb,
-	const Ray3 & ray, float * t, v3 * xnormal
+	const Ray3 & ray, float * t, v3 * xnormal, float max_dist
 ) {
 	if( aabb.maxs.x - aabb.mins.x == 2 || aabb.maxs.y - aabb.mins.y == 2 ) {
 		bool hit = false;
@@ -233,10 +232,10 @@ static bool ray_vs_quadtree_node(
 
 	for( int i = 0; i < 4; i++ ) {
 		int idx = sorted[ i ];
-		if( ts[ idx ] == FLT_MAX )
+		if( ts[ idx ] >= max_dist )
 			break;
 
-		if( ray_vs_quadtree_node( qt, child_idx( node_idx, idx ), aabbs[ idx ], ray, t, xnormal ) ) {
+		if( ray_vs_quadtree_node( qt, child_idx( node_idx, idx ), aabbs[ idx ], ray, t, xnormal, max_dist ) ) {
 			return true;
 		}
 	}
@@ -244,12 +243,12 @@ static bool ray_vs_quadtree_node(
 	return false;
 }
 
-bool ray_vs_quadtree( const QuadTree & qt, const Ray3 & ray, float * t, v3 * xnormal ) {
+bool ray_vs_quadtree( const QuadTree & qt, const Ray3 & ray, float * t, v3 * xnormal, float max_dist ) {
 	v3u32 mins = v3u32( 0, 0, qt.nodes[ 0 ].min_z );
 	v3u32 maxs = v3u32( qt.heightmap.w, qt.heightmap.h, qt.nodes[ 0 ].max_z );
 	MinMaxu32 aabb( mins, maxs );
 
-	return ray_vs_quadtree_node( qt, 0, aabb, ray, t, xnormal );
+	return ray_vs_quadtree_node( qt, 0, aabb, ray, t, xnormal, max_dist );
 }
 
 bool segment_vs_quadtree( const QuadTree & qt, const v3 & start, const v3 & end, float * t, v3 * xnormal ) {
@@ -264,15 +263,15 @@ bool segment_vs_quadtree( const QuadTree & qt, const v3 & start, const v3 & end,
 		return false;
 
 	float nt;
+	float l = length( end - start );
 	Ray3 ray( start, normalize( end - start ) );
-	bool ok = ray_vs_quadtree( qt, ray, &nt, xnormal );
-	if( !ok )
+	bool ok = ray_vs_quadtree( qt, ray, &nt, xnormal, l );
+	if( !ok || nt >= l )
 		return false;
 
-	float l = length( end - start );
 	if( t != NULL )
 		*t = nt / l;
-	return nt <= l;
+	return true;
 }
 
 void bc5_to_heightmap( MemoryArena * arena, array2d< u16 > hm, u8 * bc5 ) {
diff --git a/heightmap.h b/heightmap.h
@@ -1,5 +1,7 @@
 #pragma once
 
+#include <float.h>
+
 #include "intrinsics.h"
 #include "memory_arena.h"
 #include "array.h"
@@ -18,7 +20,7 @@ float heightmap_height( const array2d< u16 > hm, u32 x, u32 y );
 u16 heightmap_height_u16( const array2d< u16 > hm, u32 x, u32 y );
 v3 heightmap_point( const array2d< u16 > hm, u32 x, u32 y );
 
-bool ray_vs_quadtree( const QuadTree & qt, const Ray3 & ray, float * t, v3 * xnormal );
+bool ray_vs_quadtree( const QuadTree & qt, const Ray3 & ray, float * t, v3 * xnormal, float max_dist = FLT_MAX );
 bool segment_vs_quadtree( const QuadTree & qt, const v3 & start, const v3 & end, float * t, v3 * xnormal );
 
 void bc5_to_heightmap( MemoryArena * arena, array2d< u16 > hm, u8 * bc5 );