The last days I tried to get horde working with my engine and so far only one direct blocker showed: I couldn't get the terrain to work with my physics.
After some time I notices an irregularity (well, however you call that) in the height data:
http://img145.imageshack.us/my.php?image=stepgb7.png(look at the flat area where one pixel on the heightmap gets repeated)
I quickly replaced this hack with a better solution (imho):
I just changed it so that only the last pixel now gets repeated, therefore easily allowing to use the terrain because now the error isn't visible any more (and imho this is the best solution unless you allow 2^n+1-Heightmaps.
Patch:
Code:
Index: Source/terrain.cpp
===================================================================
--- Source/terrain.cpp (Revision 31)
+++ Source/terrain.cpp (Arbeitskopie)
@@ -177,9 +177,9 @@
if( u == 0 ) s = 0.0f; else if( u == size - 1 ) s = 1.0f; // Skirt
float *vertHeight = &terrain->_heightArray[v * size + u];
- const float newU = (s * scale + minU) * (terrain->_hmapSize - 1) + 0.5f;
- const float newV = (t * scale + minV) * (terrain->_hmapSize - 1) + 0.5f;
- uint32 index = ((int)newV * terrain->_hmapSize + (int)newU );
+ const float newU = (s * scale + minU) * (terrain->_hmapSize) + 0.5f;
+ const float newV = (t * scale + minV) * (terrain->_hmapSize) + 0.5f;
+ uint32 index = ((int)newV * (terrain->_hmapSize + 1) + (int)newU );
*vertHeight = terrain->_heightData[index] / 65535.0f;
@@ -312,7 +312,7 @@
hmap.getWidth() == 2048 || hmap.getWidth() == 4096 || hmap.getWidth() == 8192) )
{
_hmapSize = hmap.getWidth();
- _heightData = new unsigned short[_hmapSize * _hmapSize];
+ _heightData = new unsigned short[(_hmapSize + 1) * (_hmapSize + 1)];
float *pixels = hmap.downloadImageData();
@@ -326,10 +326,25 @@
height = (unsigned short)(clamp( pixels[(i * _hmapSize + j) * 4], 0, 1 ) * 255 * 256 +
clamp( pixels[(i * _hmapSize + j) * 4 + 1], 0, 1 ) * 255);
- _heightData[i * _hmapSize + j] = height;
+ _heightData[i * (_hmapSize + 1) + j] = height;
}
+ }
+ // Fill in last rows (just repeat last texture pixels)
+ for( uint32 i = 0; i < _hmapSize; ++i )
+ {
+ unsigned short height;
+
+ // Decode 16 bit data from red and green channels
+ height = (unsigned short)(clamp( pixels[(i * _hmapSize + _hmapSize - 1) * 4], 0, 1 ) * 255 * 256 +
+ clamp( pixels[(i * _hmapSize + _hmapSize - 1) * 4 + 1], 0, 1 ) * 255);
+
+ _heightData[i * (_hmapSize + 1) + _hmapSize] = height;
}
-
+ for( uint32 i = 0; i < _hmapSize + 1; ++i )
+ {
+ _heightData[_hmapSize * (_hmapSize + 1) + i] = _heightData[(_hmapSize - 1) * (_hmapSize + 1) + i];
+ }
+
delete[] pixels;
return true;
}
@@ -337,8 +352,8 @@
{
// Init default data
_hmapSize = 32;
- _heightData = new unsigned short[_hmapSize * _hmapSize];
- memset( _heightData, 0, _hmapSize * _hmapSize );
+ _heightData = new unsigned short[(_hmapSize + 1) * (_hmapSize + 1)];
+ memset( _heightData, 0, (_hmapSize + 1) * (_hmapSize + 1) );
Modules::log().writeDebugInfo( "Invalid heightmap data in Terrain node %i", _handle );
return false;
}
@@ -641,15 +656,15 @@
dir /= dir.length();
- int x = (int)(startX * _hmapSize);
- int y = (int)(startZ * _hmapSize);
+ int x = (int)(startX * (_hmapSize + 1));
+ int y = (int)(startZ * (_hmapSize + 1));
// Check heightmap with Bresenham algorithm (code based on http://de.wikipedia.org/wiki/Bresenham-Algorithmus)
int t, dx, dy, incX, incY, pdx, pdy, ddx, ddy, err_step_fast, err_step_slow, err;
// Get deltas in image space
- dx = (int)((endX - startX) * _hmapSize);
- dy = (int)((endZ - startZ) * _hmapSize);
+ dx = (int)((endX - startX) * (_hmapSize + 1));
+ dy = (int)((endZ - startZ) * (_hmapSize + 1));
// Check directions
incX = (dx > 0) ? 1 : (dx < 0) ? -1 : 0;
@@ -673,7 +688,7 @@
// Init error
err = err_step_slow / 2;
- float height1 = _heightData[y * _hmapSize + x] / 65535.0f, height2;
+ float height1 = _heightData[y * (_hmapSize + 1) + x] / 65535.0f, height2;
Vec3f pos;
Vec3f prevPos;
@@ -711,7 +726,7 @@
x += pdx;
y += pdy;
}
- height2 = _heightData[y * _hmapSize + x] / 65535.0f;
+ height2 = _heightData[y * (_hmapSize + 1) + x] / 65535.0f;
pos.x = x / (float)_hmapSize;
pos.z = y / (float)_hmapSize;
@@ -810,9 +825,9 @@
float s = (u - 1) * invScale;
if( u == 0 ) s = 0.0f; else if( u == size - 1 ) s = 1.0f; // Skirt
- const float newU = (s * scale + minU) * (_hmapSize - 1) + 0.4f;
- const float newV = (t * scale + minV) * (_hmapSize - 1) + 0.4f;
- uint32 index = (int)newV * _hmapSize + (int)newU;
+ const float newU = (s * scale + minU) * _hmapSize + 0.5f;
+ const float newV = (t * scale + minV) * _hmapSize + 0.5f;
+ uint32 index = (int)newV * (_hmapSize + 1) + (int)newU;
*vertData++ = (s * scale + minU);
Index: Source/terrain.h
===================================================================
--- Source/terrain.h (Revision 31)
+++ Source/terrain.h (Arbeitskopie)
@@ -141,7 +141,7 @@
BoundingBox *getLocalBBox() { return &_localBBox; }
float getHeight( float x, float y )
- { return _heightData[(int)(y * (_hmapSize - 1) + 0.5f) * _hmapSize + (int)(x * (_hmapSize - 1) + 0.5f) ] / 65535.0f; }
+ { return _heightData[(int)(y * _hmapSize + 0.5f) * (_hmapSize + 1) + (int)(x * _hmapSize + 0.5f) ] / 65535.0f; }
};
}
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