# HG changeset patch
# User John Tsiombikas <nuclear@member.fsf.org>
# Date 1419861595 -7200
# Node ID 5417c25cb23887001473f4b67fdf2f53cb9cf9a2
# Parent  04330eb80b363e013fbe6113962d2f438d8d505d
moving to a simpler transfer function

diff -r 04330eb80b36 -r 5417c25cb238 src/rend_fast.cc
--- a/src/rend_fast.cc	Mon Dec 29 05:41:36 2014 +0200
+++ b/src/rend_fast.cc	Mon Dec 29 15:59:55 2014 +0200
@@ -3,6 +3,8 @@
 #include "rend_fast.h"
 #include "sdr.h"
 
+static inline float smoothstep(float a, float b, float x);
+
 #define XFER_MAP_SZ		1024
 
 static unsigned int sdr;
@@ -55,6 +57,12 @@
 	return Renderer::transfer_curve(color);
 }
 
+void RendererFast::set_simple_transfer(float low, float high)
+{
+	xfer_tex_valid = false;
+	Renderer::set_simple_transfer(low, high);
+}
+
 void RendererFast::update(unsigned int msec)
 {
 	if(!vol) return;
@@ -118,9 +126,18 @@
 
 		for(int i=0; i<XFER_MAP_SZ; i++) {
 			float x = (float)i / (float)(XFER_MAP_SZ - 1);
+
+			// TODO make 0.1 a tweakable parameter
+			float val = smoothstep(xfer_low - 0.1, xfer_low + 0.1, x);
+			val *= 1.0 - smoothstep(xfer_high - 0.1, xfer_high + 0.1, x);
+			*pptr++ = val;
+			*pptr++ = val;
+			*pptr++ = val;
+			/*
 			*pptr++ = xfer[0].value(x);
 			*pptr++ = xfer[1].value(x);
 			*pptr++ = xfer[2].value(x);
+			*/
 		}
 
 		glBindTexture(GL_TEXTURE_1D, xfer_tex);
@@ -168,3 +185,12 @@
 	glMatrixMode(GL_MODELVIEW);
 	glPopMatrix();
 }
+
+static inline float smoothstep(float a, float b, float x)
+{
+	if(x < a) return 0.0;
+	if(x >= b) return 1.0;
+
+	x = (x - a) / (b - a);
+	return x * x * (3.0 - 2.0 * x);
+}
diff -r 04330eb80b36 -r 5417c25cb238 src/rend_fast.h
--- a/src/rend_fast.h	Mon Dec 29 05:41:36 2014 +0200
+++ b/src/rend_fast.h	Mon Dec 29 15:59:55 2014 +0200
@@ -16,6 +16,7 @@
 
 	void set_volume(Volume *vol);
 	Curve &transfer_curve(int color);
+	void set_simple_transfer(float low, float high);
 
 	void update(unsigned int msec);
 	void render() const;
diff -r 04330eb80b36 -r 5417c25cb238 src/renderer.cc
--- a/src/renderer.cc	Mon Dec 29 05:41:36 2014 +0200
+++ b/src/renderer.cc	Mon Dec 29 15:59:55 2014 +0200
@@ -12,6 +12,9 @@
 		xfer[i].set_point(1, 1);
 	}
 
+	xfer_low = 0.0;
+	xfer_high = 1.0;
+
 	for(int i=0; i<MAX_CLIP_PLANES; i++) {
 		disable_clipping_plane(i);
 	}
@@ -51,6 +54,18 @@
 	return xfer[color];
 }
 
+void Renderer::set_simple_transfer(float low, float high)
+{
+	xfer_low = std::min(low, high);
+	xfer_high = std::max(low, high);
+}
+
+void Renderer::get_simple_transfer(float *low, float *high) const
+{
+	*low = xfer_low;
+	*high = xfer_high;
+}
+
 void Renderer::set_clipping_plane(int idx, float nx, float ny, float nz, float dist)
 {
 	float len = sqrt(nx * nx + ny * ny + nz * nz);
diff -r 04330eb80b36 -r 5417c25cb238 src/renderer.h
--- a/src/renderer.h	Mon Dec 29 05:41:36 2014 +0200
+++ b/src/renderer.h	Mon Dec 29 15:59:55 2014 +0200
@@ -14,6 +14,7 @@
 	float clip_plane[MAX_CLIP_PLANES][4];	// nx,ny,nz,dist
 
 	Curve xfer[3];	// rgb transfer function
+	float xfer_low, xfer_high;	// simple transfer function bounds
 
 public:
 	Renderer();
@@ -28,6 +29,9 @@
 	virtual Curve &transfer_curve(int color);
 	virtual const Curve &transfer_curve(int color) const;
 
+	virtual void set_simple_transfer(float low, float high);
+	virtual void get_simple_transfer(float *low, float *high) const;
+
 	virtual void set_clipping_plane(int idx, float nx, float ny, float nz, float dist);
 	virtual void disable_clipping_plane(int idx);
 
diff -r 04330eb80b36 -r 5417c25cb238 src/xfer_view.cc
--- a/src/xfer_view.cc	Mon Dec 29 05:41:36 2014 +0200
+++ b/src/xfer_view.cc	Mon Dec 29 15:59:55 2014 +0200
@@ -6,7 +6,7 @@
 static Renderer *rend;
 
 static int act_color = 3;
-static CurvePoint *cpsel[3];
+static CurvePoint *cpsel;
 
 bool xfview_init(Renderer *rendarg)
 {
@@ -109,13 +109,17 @@
 
 void xfview_button(int bn, int press, int x, int y)
 {
-	if(bn == 2 && press) {
+	if(bn == 2 && press && !cpsel) {
 		act_color = (act_color + 1) % 4;
 		redisplay();
 		return;
 	}
 
-	if(press) {
+	if(bn == 1) {
+		if(press) {
+		} else {
+			cpsel = 0;
+		}
 	}
 }