paysages3d/src/render/software/CloudBasicLayerRenderer.cpp

243 lines
7.3 KiB
C++

#include "CloudBasicLayerRenderer.h"
#include "CloudLayerDefinition.h"
#include "SoftwareRenderer.h"
#include "NoiseGenerator.h"
#include "Curve.h"
#include "AtmosphereRenderer.h"
#include "AtmosphereResult.h"
#include "LightComponent.h"
#include "clouds/BaseCloudsModel.h"
#include "SurfaceMaterial.h"
#include "Logs.h"
struct CloudSegment
{
Vector3 start;
Vector3 end;
double length;
};
CloudBasicLayerRenderer::CloudBasicLayerRenderer(SoftwareRenderer* parent):
BaseCloudLayerRenderer(parent)
{
}
static inline double _getDistanceToBorder(BaseCloudsModel* model, Vector3 position)
{
return model->getDensity(position);
}
/**
* Go through the cloud layer to find segments (parts of the lookup that are inside the cloud).
*
* @param definition The cloud layer
* @param renderer The renderer environment
* @param start Start position of the lookup (already optimized)
* @param direction Normalized direction of the lookup
* @param detail Level of noise detail required
* @param max_segments Maximum number of segments to collect
* @param max_inside_length Maximum length to spend inside the cloud
* @param max_total_length Maximum lookup length
* @param inside_length Resulting length inside cloud (sum of all segments length)
* @param total_length Resulting lookup length
* @param out_segments Allocated space to fill found segments
* @return Number of segments found
*/
int CloudBasicLayerRenderer::findSegments(BaseCloudsModel *model, const Vector3 &start, const Vector3 &direction, int max_segments, double max_inside_length, double max_total_length, double* inside_length, double* total_length, CloudSegment* out_segments)
{
double ymin, ymax;
int inside, segment_count;
double current_total_length, current_inside_length;
double step_length, segment_length;
double min_step, max_step;
double noise_distance;
Vector3 walker, step, segment_start;
double render_precision;
if (max_segments <= 0)
{
return 0;
}
model->getAltitudeRange(&ymin, &ymax);
model->getDetailRange(&min_step, &max_step);
render_precision = max_step - quality * (max_step - min_step);
if (render_precision > max_total_length / 10.0)
{
render_precision = max_total_length / 10.0;
}
else if (render_precision < max_total_length / 2000.0)
{
render_precision = max_total_length / 2000.0;
}
segment_count = 0;
current_total_length = 0.0;
current_inside_length = 0.0;
segment_length = 0.0;
walker = start;
noise_distance = _getDistanceToBorder(model, start) * render_precision;
inside = 0;
step = direction.scale(render_precision);
do
{
walker = walker.add(step);
step_length = step.getNorm();
noise_distance = _getDistanceToBorder(model, walker) * render_precision;
current_total_length += step_length;
if (noise_distance > 0.0)
{
if (inside)
{
// inside the cloud
segment_length += step_length;
current_inside_length += step_length;
step = direction.scale((noise_distance < render_precision) ? render_precision : noise_distance);
}
else
{
// entering the cloud
inside = 1;
segment_length = 0.0;
segment_start = walker;
current_inside_length += segment_length;
step = direction.scale(render_precision);
}
}
else
{
if (inside)
{
// exiting the cloud
segment_length += step_length;
current_inside_length += step_length;
out_segments->start = segment_start;
out_segments->end = walker;
out_segments->length = segment_length;
out_segments++;
if (++segment_count >= max_segments)
{
break;
}
inside = 0;
step = direction.scale(render_precision);
}
else
{
// searching for a cloud
step = direction.scale((noise_distance > -render_precision) ? render_precision : -noise_distance);
}
}
} while (inside || (walker.y >= ymin - 0.001 && walker.y <= ymax + 0.001 && current_total_length < max_total_length && current_inside_length < max_inside_length));
*total_length = current_total_length;
*inside_length = current_inside_length;
return segment_count;
}
Color CloudBasicLayerRenderer::getColor(BaseCloudsModel *model, const Vector3 &eye, const Vector3 &location)
{
int i, segment_count;
double max_length, total_length, inside_length;
Vector3 start, end, direction;
Color result, col;
CloudSegment segments[20];
start = eye;
end = location;
if (!optimizeSearchLimits(model, &start, &end))
{
return COLOR_TRANSPARENT;
}
direction = end.sub(start);
max_length = direction.getNorm();
direction = direction.normalize();
result = COLOR_TRANSPARENT;
double ymin, ymax;
model->getAltitudeRange(&ymin, &ymax);
double transparency_depth = (ymax - ymin) * 0.5;
segment_count = findSegments(model, start, direction, 20, transparency_depth, max_length, &inside_length, &total_length, segments);
for (i = segment_count - 1; i >= 0; i--)
{
SurfaceMaterial material(COLOR_WHITE);
material.hardness = 0.25;
material.reflection = 0.0;
material.shininess = 0.0;
material.validate();
col = parent->applyLightingToSurface(segments[i].start, parent->getAtmosphereRenderer()->getSunDirection(), material);
double power = col.getPower();
if (power > 0.2)
{
col.r += (power - 0.2) * 1.5;
col.g += (power - 0.2) * 1.5;
col.b += (power - 0.2) * 1.5;
}
col.a = (segments[i].length >= transparency_depth) ? 1.0 : (segments[i].length / transparency_depth);
result.mask(col);
}
if (inside_length >= transparency_depth)
{
result.a = 1.0;
}
double a = result.a;
result = parent->getAtmosphereRenderer()->applyAerialPerspective(start, result).final;
result.a = a;
return result;
}
bool CloudBasicLayerRenderer::alterLight(BaseCloudsModel *model, LightComponent* light, const Vector3 &, const Vector3 &location)
{
Vector3 start, end, direction;
double inside_depth, total_depth, factor;
CloudSegment segments[20];
start = location;
direction = light->direction.scale(-1.0);
end = location.add(direction.scale(10000.0));
if (not optimizeSearchLimits(model, &start, &end))
{
return false;
}
double ymin, ymax;
model->getAltitudeRange(&ymin, &ymax);
double light_traversal = (ymax - ymin) * 1.2;
findSegments(model, start, direction, 20, light_traversal, end.sub(start).getNorm(), &inside_depth, &total_depth, segments);
if (light_traversal < 0.0001)
{
factor = 0.0;
}
else
{
factor = inside_depth / light_traversal;
if (factor > 1.0)
{
factor = 1.0;
}
}
double miminum_light = 0.3;
factor = 1.0 - (1.0 - miminum_light) * factor;
light->color.r *= factor;
light->color.g *= factor;
light->color.b *= factor;
return true;
}