# HG changeset patch
# User Eleni Maria Stea <elene.mst@gmail.com>
# Date 1393881133 -7200
# Node ID 0f4fff558737b579b5508e47039b343671b917e9
# Parent  add30e2d525314e2c1460d5e6f8c34932e11c45a
transfer function

diff -r add30e2d5253 -r 0f4fff558737 src/main.cc
--- a/src/main.cc	Mon Feb 03 02:52:46 2014 +0200
+++ b/src/main.cc	Mon Mar 03 23:12:13 2014 +0200
@@ -2,6 +2,7 @@
 #include <GL/glut.h>
 #include <GL/glui.h>
 
+#include <math.h>
 #include <stdio.h>
 #include <assert.h>
 
@@ -22,7 +23,9 @@
 static bool init_xfer(void);
 static void display_xfer(void);
 static void reshape_xfer(int x, int y);
+static void mouse_xfer(int button, int state, int x, int y);
 static void motion_xfer(int x, int y);
+//todo keyb esc
 
 static int mainwin_id, xferwin_id;
 
@@ -320,6 +323,7 @@
 	xferwin_id = glutCreateWindow("Transfer Function");
 	glutDisplayFunc(display_xfer);
 	glutReshapeFunc(reshape_xfer);
+	glutMouseFunc(mouse_xfer);
 	glutMotionFunc(motion_xfer);
 
 	return true;
@@ -342,7 +346,34 @@
 		high = thres;
 	}
 
-	glBegin(GL_QUADS);
+	//drawing the transfer function curve
+
+	glLineWidth(3);
+	glBegin(GL_LINE_STRIP);
+	glColor3f(0.8, 0.3, 0.8);
+	for(int i=0; i<num_val; i++) {
+		float val = transfer_function(x, low, high);
+		glVertex2f(x, val);
+		x += dx;
+	}
+	glEnd();
+
+	//threshold bars
+
+	glLineWidth(2);
+	glBegin(GL_LINES);
+	glColor3f(0.4, 0.4, 0.8);
+	glVertex2f(low, 0);
+	glVertex2f(low, 1);
+	glColor3f(0.4, 0.8, 0.4);
+	glVertex2f(high, 0);
+	glVertex2f(high, 1);
+	glEnd();
+
+/*
+ * gradient
+ */
+/*  glBegin(GL_QUADS);
 	for(int i=0; i<num_val; i++) {
 		float val = transfer_function(x, low, high);
 		glColor3f(val, val, val);
@@ -355,7 +386,7 @@
 		glVertex3f(x + dx, 1.0, 0.0);
 		x += dx;
 	}
-	glEnd();
+	glEnd(); */
 
 	glutSwapBuffers();
 	assert(glGetError() == GL_NO_ERROR);
@@ -369,8 +400,43 @@
 	glOrtho(0.0, 1.0, 0.0, 1.0, -1.0, 1.0);
 }
 
+static float *select_thres;
+static float prev_select_thres;
+static void mouse_xfer(int button, int state, int x, int y)
+{
+	if(button == GLUT_LEFT_BUTTON) {
+		if(state == GLUT_DOWN) {
+			int width = glutGet(GLUT_WINDOW_WIDTH);
+			float xpos = (float)x / (float)width;
+			if(fabs(xpos - thres) <= fabs(xpos - thres2)) {
+				select_thres = &thres;
+			}
+			else {
+				select_thres = &thres2;
+			}
+			prev_select_thres = *select_thres;
+		}
+		else {
+			if(fabs(*select_thres - prev_select_thres) > 0.001) {
+				mesh->clear();
+				ui->sync_live();
+			}
+			select_thres = 0;
+		}
+	}
+}
+
 static void motion_xfer(int x, int y)
 {
-	//to pontiki sto kontinotero akro
-	//glutPostRedisplay k sta 2 win
+	if(!select_thres)
+		return;
+
+	int width = glutGet(GLUT_WINDOW_WIDTH);
+	float xpos = (float)x / (float)width;
+
+	*select_thres = xpos;
+
+	glutPostRedisplay();
+	glutSetWindow(mainwin_id);
+	glutPostRedisplay();
 }