137 lines
4.2 KiB
C++
137 lines
4.2 KiB
C++
#include "TerrainRayWalker.h"
|
|
|
|
#include "SoftwareRenderer.h"
|
|
#include "Scenery.h"
|
|
#include "TerrainDefinition.h"
|
|
#include "TexturesDefinition.h"
|
|
#include "TerrainRenderer.h"
|
|
#include "TexturesRenderer.h"
|
|
#include "Matrix4.h"
|
|
|
|
TerrainRayWalker::TerrainRayWalker(SoftwareRenderer* renderer):
|
|
renderer(renderer)
|
|
{
|
|
}
|
|
|
|
void TerrainRayWalker::update()
|
|
{
|
|
TerrainDefinition* terrain = renderer->getScenery()->getTerrain();
|
|
HeightInfo info = terrain->getHeightInfo();
|
|
|
|
TexturesDefinition* textures = renderer->getScenery()->getTextures();
|
|
double disp = textures->getMaximalDisplacement();
|
|
|
|
ymin = info.min_height - disp;
|
|
ymax = info.max_height + disp;
|
|
|
|
ydispmax = disp * (0.5 + (double)renderer->render_quality * 0.1);
|
|
ydispmin = -ydispmax;
|
|
|
|
minstep = 1.0 * terrain->scaling / (double)(renderer->render_quality * renderer->render_quality);
|
|
maxstep = 10.0 * terrain->scaling / (double)renderer->render_quality;
|
|
}
|
|
|
|
static inline Vector3 _getShiftAxis(const Vector3 &direction)
|
|
{
|
|
if (fabs(direction.y) > 0.99)
|
|
{
|
|
// When the ray is vertical, we choose an arbitrary shift axis
|
|
return VECTOR_NORTH;
|
|
}
|
|
else
|
|
{
|
|
return VECTOR_UP.crossProduct(direction);
|
|
}
|
|
}
|
|
|
|
bool TerrainRayWalker::startWalking(const Vector3 &start, Vector3 direction, double escape_angle, double max_length, TerrainHitResult &result)
|
|
{
|
|
TerrainRenderer* terrain_renderer = renderer->getTerrainRenderer();
|
|
TexturesRenderer* textures_renderer = renderer->getTexturesRenderer();
|
|
TerrainRenderer::TerrainResult terrain_result;
|
|
Vector3 cursor, displaced;
|
|
double diff;
|
|
Matrix4 shift_matrix;
|
|
double shift_step = 0.0;
|
|
|
|
Vector3 previous_cursor = start;
|
|
bool hit = false;
|
|
double step_length = minstep;
|
|
double walked_length = 0.0;
|
|
|
|
result.escape_angle = 0.0;
|
|
if (escape_angle != 0.0)
|
|
{
|
|
// Prepare escape
|
|
shift_step = escape_angle / (double)(renderer->render_quality * renderer->render_quality);
|
|
shift_matrix = Matrix4::newRotateAxis(-shift_step, _getShiftAxis(direction));
|
|
}
|
|
|
|
do
|
|
{
|
|
// Perform a step
|
|
cursor = previous_cursor.add(direction.scale(step_length));
|
|
|
|
// Get the terrain info at end (without textures displacement)
|
|
terrain_result = terrain_renderer->getResult(cursor.x, cursor.z, true, false);
|
|
diff = cursor.y - terrain_result.location.y;
|
|
|
|
// If we are very under the terrain, consider a hit
|
|
if (diff < ydispmin)
|
|
{
|
|
hit = true;
|
|
}
|
|
|
|
// If we are close enough to the terrain, apply displacement
|
|
else if (diff < ydispmax)
|
|
{
|
|
displaced = textures_renderer->displaceTerrain(terrain_result);
|
|
diff = cursor.y - displaced.y;
|
|
hit = diff < 0.0;
|
|
}
|
|
|
|
if (hit)
|
|
{
|
|
// TODO Refine the hit with dichotomy at high quality
|
|
/*if (renderer->render_quality > 7)
|
|
{
|
|
cursor = refineHit(previous_cursor, cursor, step_length);
|
|
}*/
|
|
|
|
// Shift ray to escape terrain
|
|
if (escape_angle != 0.0)
|
|
{
|
|
result.escape_angle += shift_step;
|
|
if (result.escape_angle > escape_angle)
|
|
{
|
|
// Too much shifted to escape, make it a hit
|
|
result.escape_angle = 0.0;
|
|
return true;
|
|
}
|
|
hit = false;
|
|
direction = shift_matrix.multPoint(direction);
|
|
previous_cursor = start.add(shift_matrix.multPoint(previous_cursor.sub(start)));
|
|
}
|
|
|
|
result.hit_location = cursor;
|
|
}
|
|
else
|
|
{
|
|
// Prepare next step
|
|
previous_cursor = cursor;
|
|
walked_length += step_length;
|
|
|
|
step_length = diff * 3.0 / (double)renderer->render_quality;
|
|
if (step_length < minstep)
|
|
{
|
|
step_length = minstep;
|
|
}
|
|
else if (step_length > maxstep)
|
|
{
|
|
step_length = maxstep;
|
|
}
|
|
}
|
|
} while (not hit and cursor.y < ymax and walked_length < max_length);
|
|
|
|
return hit or result.escape_angle > 0.0;
|
|
}
|