1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/src/xfermap.cc	Tue Dec 30 06:22:54 2014 +0200
     1.3 @@ -0,0 +1,77 @@
     1.4 +#include <algorithm>
     1.5 +#include "xfermap.h"
     1.6 +
     1.7 +TransferFunc::~TransferFunc()
     1.8 +{
     1.9 +}
    1.10 +
    1.11 +
    1.12 +// ---- TransferWindow ----
    1.13 +
    1.14 +TransferWindow::TransferWindow()
    1.15 +{
    1.16 +	soft_rad = 0.5;
    1.17 +	for(int i=0; i<4; i++) {
    1.18 +		low[i] = 0.5;
    1.19 +		high[i] = 2.0;
    1.20 +	}
    1.21 +}
    1.22 +
    1.23 +void TransferWindow::set_interval(float a, float b)
    1.24 +{
    1.25 +	float v0 = std::min(a, b);
    1.26 +	float v1 = std::max(a, b);
    1.27 +
    1.28 +	for(int i=0; i<4; i++) {
    1.29 +		low[i] = v0;
    1.30 +		high[i] = v1;
    1.31 +	}
    1.32 +}
    1.33 +
    1.34 +void TransferWindow::set_interval(float *rgba_low, float *rgba_high)
    1.35 +{
    1.36 +	for(int i=0; i<4; i++) {
    1.37 +		low[i] = std::min(rgba_low[i], rgba_high[i]);
    1.38 +		high[i] = std::max(rgba_low[i], rgba_high[i]);
    1.39 +	}
    1.40 +}
    1.41 +
    1.42 +void TransferWindow::set_interval_rgba(int channel, float a, float b)
    1.43 +{
    1.44 +	low[channel] = std::min(a, b);
    1.45 +	high[channel] = std::max(a, b);
    1.46 +}
    1.47 +
    1.48 +void TransferWindow::set_soft_radius(float s)
    1.49 +{
    1.50 +	soft_rad = s;
    1.51 +}
    1.52 +
    1.53 +float TransferWindow::get_soft_radius() const
    1.54 +{
    1.55 +	return soft_rad;
    1.56 +}
    1.57 +
    1.58 +static inline float smoothstep(float a, float b, float x)
    1.59 +{
    1.60 +	if(x < a) return 0.0f;
    1.61 +	if(x >= b) return 1.0f;
    1.62 +
    1.63 +	float t = (x - a) / (b - a);
    1.64 +	return t * t * (3.0f - 2.0f * t);
    1.65 +}
    1.66 +
    1.67 +float TransferWindow::map(float x) const
    1.68 +{
    1.69 +	return smoothstep(low[3] - soft_rad, high[3] - soft_rad, x) *
    1.70 +		(1.0 - smoothstep(low[3] + soft_rad, high[3] + soft_rad, x));
    1.71 +}
    1.72 +
    1.73 +void TransferWindow::map(float x, float *rgba_value) const
    1.74 +{
    1.75 +	for(int i=0; i<4; i++) {
    1.76 +		float val = smoothstep(low[i] - soft_rad, high[i] - soft_rad, x);
    1.77 +		val *= 1.0 - smoothstep(low[i] + soft_rad, high[i] + soft_rad, x);
    1.78 +		rgba_value[i] = val;
    1.79 +	}
    1.80 +}