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Fix math for isBlockInSight. Fixes #718 (client-side).
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Warr1024 authored and PilzAdam committed May 17, 2013
1 parent fedf644 commit 1369503
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Showing 2 changed files with 18 additions and 18 deletions.
3 changes: 1 addition & 2 deletions src/camera.cpp
Expand Up @@ -342,8 +342,7 @@ void Camera::update(LocalPlayer* player, f32 frametime, v2u32 screensize,
m_fov_y = fov_degrees * M_PI / 180.0;
// Increase vertical FOV on lower aspect ratios (<16:10)
m_fov_y *= MYMAX(1.0, MYMIN(1.4, sqrt(16./10. / m_aspect)));
// WTF is this? It can't be right
m_fov_x = 2 * atan(0.5 * m_aspect * tan(m_fov_y));
m_fov_x = 2 * atan(m_aspect * tan(0.5 * m_fov_y));
m_cameranode->setAspectRatio(m_aspect);
m_cameranode->setFOV(m_fov_y);

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33 changes: 17 additions & 16 deletions src/util/numeric.cpp
Expand Up @@ -159,40 +159,41 @@ bool isBlockInSight(v3s16 blockpos_b, v3f camera_pos, v3f camera_dir,
// Block position relative to camera
v3f blockpos_relative = blockpos - camera_pos;

// Distance in camera direction (+=front, -=back)
f32 dforward = blockpos_relative.dotProduct(camera_dir);

// Total distance
f32 d = blockpos_relative.getLength();

if(distance_ptr)
*distance_ptr = d;

// If block is very close, it is always in sight
if(d < 1.44*1.44*MAP_BLOCKSIZE*BS/2)
return true;

// If block is far away, it's not in sight
if(d > range)
return false;

// Maximum radius of a block
f32 block_max_radius = 0.5*1.44*1.44*MAP_BLOCKSIZE*BS;
// Maximum radius of a block. The magic number is
// sqrt(3.0) / 2.0 in literal form.
f32 block_max_radius = 0.866025403784 * MAP_BLOCKSIZE * BS;

// If block is (nearly) touching the camera, don't
// bother validating further (that is, render it anyway)
if(d < block_max_radius)
return true;


// Adjust camera position, for purposes of computing the angle,
// such that a block that has any portion visible with the
// current camera position will have the center visible at the
// adjusted postion
f32 adjdist = block_max_radius / cos((M_PI - camera_fov) / 2);

// Block position relative to adjusted camera
v3f blockpos_adj = blockpos - (camera_pos - camera_dir * adjdist);

// Distance in camera direction (+=front, -=back)
f32 dforward = blockpos_adj.dotProduct(camera_dir);

// Cosine of the angle between the camera direction
// and the block direction (camera_dir is an unit vector)
f32 cosangle = dforward / d;
f32 cosangle = dforward / blockpos_adj.getLength();

// Compensate for the size of the block
// (as the block has to be shown even if it's a bit off FOV)
// This is an estimate, plus an arbitary factor
cosangle += block_max_radius / d * 0.5;

// If block is not in the field of view, skip it
if(cosangle < cos(camera_fov / 2))
return false;
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