Changeset 434 for trunk/gui/vizservers/nanovis

Timestamp:

May 9, 2006, 2:55:08 PM (18 years ago)

Author:

mmc

Message:

Added separate controls for outline enable/disable/color, and volume
data enable/disable.

Location:

trunk/gui/vizservers/nanovis

Files:

• Color.cpp (modified) (1 diff)
• Color.h (modified) (2 diffs)
• Makefile (modified) (2 diffs)
• Volume.cpp (modified) (2 diffs)
• Volume.h (modified) (3 diffs)
• VolumeRenderer.cpp (modified) (3 diffs)
• config.h (modified) (1 diff)
• define.h (modified) (1 diff)
• nanovis.cpp (modified) (15 diffs)

trunk/gui/vizservers/nanovis/Color.cpp

@@ -18 +18 @@
 
 #include "Color.h"
+#include "define.h"
 
-Color::Color(){
+Color::Color() {
         R=G=B=0.0;
         next=0;
 }
 
-Color::Color(double r, double g, double b){
+Color::Color(double r, double g, double b) {
         R=r;
         G=g;
         B=b;
         next=0;
+}
+
+Color::Color(const Color& c)
+ : R(c.R), G(c.G), B(c.B), next(c.next)
+{
+}
+
+Color&
+Color::operator=(const Color& c)
+{
+    R = c.R;
+    G = c.G;
+    B = c.B;
+    next = c.next;
+    return *this;
 }
 

trunk/gui/vizservers/nanovis/Color.h

@@ -34 +34 @@
         Color();
         Color(double r, double g, double b);
+        Color(const Color& c);
+        Color& operator=(const Color& c);
+        ~Color();
 
         void LimitColors(); //Limits the color to be in range of 0.0 and 1.0
@@ -39 +42 @@
         friend Color operator*(double k, Color &other);
         Color operator+(Color &other);
-        ~Color();
-        float r, g, b, a;
 };
 

trunk/gui/vizservers/nanovis/Makefile

@@ -15 +15 @@
 NANOSCALESRC = ./nanoscale
 
-LIB_NANOVIS = -ltcl8.4 -L/opt/render/lib -lGL -lglut -lglui -lGLEW -lCg -lCgGL -pthread -lstdc++
+LIB_NANOVIS = -ltcl8.3 -L/opt/render/lib -lGL -lglut -lglui -lGLEW -lCg -lCgGL -pthread -lstdc++
 LIB_CLIENT = -L/opt/render/lib -lGL -lglut -pthread -lstdc++
-INCLUDES = -I../src2/core -I/opt/render/include -I/autohome/u76/qiaow/Cg/usr/include
+INCLUDES = -I../../src2/core -I/opt/render/include -I/autohome/u76/qiaow/Cg/usr/include
 CFLAG = -g -c $(INCLUDES)
 
@@ -26 +26 @@
 
 nanovis: $(OBJ_NANOVIS)
-        gcc -g -o nanovis $(OBJ_NANOVIS) $(LIB_NANOVIS) ../src2/core/*.o
+        gcc -g -o nanovis $(OBJ_NANOVIS) $(LIB_NANOVIS) ../../src2/core/*.o
 
 ColorGradient.o: Color.o $(TFSRC)/ColorGradient.cpp

trunk/gui/vizservers/nanovis/Volume.cpp

@@ -27 +27 @@
         n_components(n),
         enabled(true),
-        n_slice(256), //defualt value
-        specular(6.), //defualt value
-        diffuse(3.), //defualt value
-        opacity_scale(10.) //defualt value
+        n_slice(256), // default value
+        specular(6.), // default value
+        diffuse(3.), // default value
+        opacity_scale(10.), // default value
+        data_enabled(true), // default value
+        outline_enabled(true), // default value
+        outline_color(1.,1.,1.) // default value
 {
 
@@ -113 +116 @@
 void Volume::set_diffuse(float d) { diffuse = d; }
 void Volume::set_opacity_scale(float s) { opacity_scale = s; }
+
+void Volume::enable_data() { data_enabled = true; }
+void Volume::disable_data() { data_enabled = false; }
+bool Volume::data_is_enabled() { return data_enabled; }
+
+void Volume::enable_outline() { outline_enabled = true; }
+void Volume::disable_outline() { outline_enabled = false; }
+bool Volume::outline_is_enabled() { return outline_enabled; }
+void Volume::set_outline_color(float *rgb) {
+    outline_color = Color(rgb[0],rgb[1],rgb[2]);
+}
+void Volume::get_outline_color(float *rgb) {
+    outline_color.GetRGB(rgb);
+}

trunk/gui/vizservers/nanovis/Volume.h

@@ -20 +20 @@
 
 #include "define.h"
+#include "Color.h"
 #include "Texture3D.h"
 #include "Vector3.h"
@@ -48 +49 @@
         float opacity_scale;    //The scale multiplied to the opacity assigned by the transfer function.
                                 //Rule of thumb: higher opacity_scale the object is to appear like plastic
+
+        bool data_enabled;      // show/hide cloud of volume data
+
+        bool outline_enabled;   // show/hide outline around volume
+        Color outline_color;    // color for outline around volume
 
 public:
@@ -102 +108 @@
         void set_opacity_scale(float s);
 
+        void enable_data();
+        void disable_data();
+        bool data_is_enabled();
+
+        void enable_outline();
+        void disable_outline();
+        bool outline_is_enabled();
+        void set_outline_color(float* rgb);
+        void get_outline_color(float* rgb);
 };
 

trunk/gui/vizservers/nanovis/VolumeRenderer.cpp

@@ -157 +157 @@
 
     //draw volume bounding box with translation (the correct location in space)
-    draw_bounding_box(x0, y0, z0, x0+1, y0+1, z0+1, 0.8, 0.1, 0.1, 1.5);
+    if (volume[i]->outline_is_enabled()) {
+        float olcolor[3];
+        volume[i]->get_outline_color(olcolor);
+        draw_bounding_box(x0, y0, z0, x0+1, y0+1, z0+1,
+            (double)olcolor[0], (double)olcolor[1], (double)olcolor[2],
+            1.5);
+    }
     glPopMatrix();
 
@@ -167 +173 @@
     //compute actual rendering slices
     float z_step = fabs(zNear-zFar)/n_slices;           
-    int n_actual_slices = (int)(fabs(zNear-zFar)/z_step + 1);
-
-    //if no cloud
-    //n_actual_slices = 0;
-    
+    int n_actual_slices;
+
+    if (volume[i]->data_is_enabled()) {
+        n_actual_slices = (int)(fabs(zNear-zFar)/z_step + 1);
+        polys[cur_vol] = new ConvexPolygon*[n_actual_slices];
+    } else {
+        n_actual_slices = 0;
+        polys[cur_vol] = NULL;
+    }
     actual_slices[cur_vol] = n_actual_slices;
-    polys[cur_vol] = new ConvexPolygon*[n_actual_slices];
-
-    //if no cloud
-    //polys[cur_vol] = NULL;
-
-    float slice_z;
 
     Vector4 vert1 = (Vector4(-10, -10, -0.5, 1));
@@ -268 +272 @@
     
     //transform slices and store them
+    float slice_z;
     for (int i=0; i<n_actual_slices; i++){
       slice_z = zFar + i * z_step;      //back to front

trunk/gui/vizservers/nanovis/config.h

@@ -16 +16 @@
 
 #define NV40      //Uncomment if using 6 series card. By default we assume older card the 5xxx series
-//#define XINETD  //enable render server
+#define XINETD  //enable render server
 //#define EVENTLOG  //enable event logging
 //#define DO_RLE  //do run length compression

trunk/gui/vizservers/nanovis/define.h

@@ -54 +54 @@
    }
 
+// use this to send debug messages back to the client
+void debug(char *message);
+void debug(char *message, double v1);
+void debug(char *message, double v1, double v2);
+void debug(char *message, double v1, double v2, double v3);
 
 #endif

trunk/gui/vizservers/nanovis/nanovis.cpp

@@ -41 +41 @@
 Camera* cam;
 
-bool volume_mode = false; //if true nanovis renders volumes in 3D, if not renders 2D plane
+//if true nanovis renders volumes in 3D, if not renders 2D plane
+bool volume_mode = true;
 
 // color table for built-in transfer function editor
@@ -120 +121 @@
 static int CutplaneCmd _ANSI_ARGS_((ClientData cdata, Tcl_Interp *interp, int argc, CONST84 char *argv[]));
 static int ClearCmd _ANSI_ARGS_((ClientData cdata, Tcl_Interp *interp, int argc, CONST84 char *argv[]));
-static int ScreenResizeCmd _ANSI_ARGS_((ClientData cdata, Tcl_Interp *interp, int argc, CONST84 char *argv[]));
+static int ScreenCmd _ANSI_ARGS_((ClientData cdata, Tcl_Interp *interp, int argc, CONST84 char *argv[]));
 static int TransferFunctionNewCmd _ANSI_ARGS_((ClientData cdata, Tcl_Interp *interp, int argc, CONST84 char *argv[]));
 static int TransferFunctionUpdateCmd _ANSI_ARGS_((ClientData cdata, Tcl_Interp *interp, int argc, CONST84 char *argv[]));
+static int VolumeCmd _ANSI_ARGS_((ClientData cdata, Tcl_Interp *interp, int argc, CONST84 char *argv[]));
 static int VolumeNewCmd _ANSI_ARGS_((ClientData cdata, Tcl_Interp *interp, int argc, CONST84 char *argv[]));
 static int VolumeLinkCmd _ANSI_ARGS_((ClientData cdata, Tcl_Interp *interp, int argc, CONST84 char *argv[]));
 static int VolumeMoveCmd _ANSI_ARGS_((ClientData cdata, Tcl_Interp *interp, int argc, CONST84 char *argv[]));
 static int VolumeEnableCmd _ANSI_ARGS_((ClientData cdata, Tcl_Interp *interp, int argc, CONST84 char *argv[]));
-static int OutlineCmd _ANSI_ARGS_((ClientData cdata, Tcl_Interp *interp, int argc, CONST84 char *argv[]));
 static int RefreshCmd _ANSI_ARGS_((ClientData cdata, Tcl_Interp *interp, int argc, CONST84 char *argv[]));
-static int Switch2D3DCmd _ANSI_ARGS_((ClientData cdata, Tcl_Interp *interp, int argc, CONST84 char *argv[]));
 static int PlaneNewCmd _ANSI_ARGS_((ClientData cdata, Tcl_Interp *interp, int argc, CONST84 char *argv[]));
 static int PlaneLinkCmd _ANSI_ARGS_((ClientData cdata, Tcl_Interp *interp, int argc, CONST84 char *argv[]));
 static int PlaneEnableCmd _ANSI_ARGS_((ClientData cdata, Tcl_Interp *interp, int argc, CONST84 char *argv[]));
 
-static int DecodeAxis _ANSI_ARGS_((Tcl_Interp *interp, char *str, int *valPtr));
+static int GetAxis _ANSI_ARGS_((Tcl_Interp *interp, char *str, int *valPtr));
+static int GetColor _ANSI_ARGS_((Tcl_Interp *interp, char *str, float *rgbPtr));
 
 /*
@@ -262 +263 @@
 
         int axis;
-        if (DecodeAxis(interp, (char*)argv[3], &axis) != TCL_OK) {
+        if (GetAxis(interp, argv[3], &axis) != TCL_OK) {
             return TCL_ERROR;
         }
@@ -305 +306 @@
             return TCL_ERROR;
         }
+        // keep this just inside the volume so it doesn't disappear
+        if (relval < 0.01) { relval = 0.01; }
+        if (relval > 0.99) { relval = 0.99; }
 
         int axis;
-        if (DecodeAxis(interp, (char*)argv[3], &axis) != TCL_OK) {
+        if (GetAxis(interp, argv[3], &axis) != TCL_OK) {
             return TCL_ERROR;
         }
@@ -337 +341 @@
 }
 
-/*
- * ----------------------------------------------------------------------
- * FUNCTION: DecodeAxis()
- *
- * Used internally to decode an axis value from a string ("x", "y",
- * or "z") to its index (0, 1, or 2).  Returns TCL_OK if successful,
- * along with a value in valPtr.  Otherwise, it returns TCL_ERROR
- * and an error message in the interpreter.
- * ----------------------------------------------------------------------
- */
-static int
-DecodeAxis(Tcl_Interp *interp, char *str, int *valPtr)
-{
-    if (strcmp(str,"x") == 0) {
-        *valPtr = 0;
-        return TCL_OK;
-    }
-    else if (strcmp(str,"y") == 0) {
-        *valPtr = 1;
-        return TCL_OK;
-    }
-    else if (strcmp(str,"z") == 0) {
-        *valPtr = 2;
-        return TCL_OK;
-    }
-    Tcl_AppendResult(interp, "bad axis \"", str,
-        "\": should be x, y, or z", (char*)NULL);
-    return TCL_ERROR;
-}
-
 void resize_offscreen_buffer(int w, int h);
 
 //change screen size
 static int
-ScreenResizeCmd(ClientData cdata, Tcl_Interp *interp, int argc, CONST84 char *argv[])
+ScreenCmd(ClientData cdata, Tcl_Interp *interp, int argc, CONST84 char *argv[])
 {
 
@@ -470 +444 @@
   live_obj_y = y;
   live_obj_z = z;
+}
+
+/*
+ * ----------------------------------------------------------------------
+ * CLIENT COMMAND:
+ *   volume outline state on|off ?<volumeId> ...?
+ *   volume outline color on|off ?<volumeId> ...?
+ *   volume data state on|off ?<volumeId> ...?
+ *
+ * Clients send these commands to manipulate the volumes.
+ * ----------------------------------------------------------------------
+ */
+static int
+VolumeCmd(ClientData cdata, Tcl_Interp *interp, int argc, CONST84 char *argv[])
+{
+        if (argc < 2) {
+                Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+                        " option arg arg...\"", (char*)NULL);
+                return TCL_ERROR;
+    }
+
+    char c = *argv[1];
+        if (c == 'o' && strcmp(argv[1],"outline") == 0) {
+        if (argc < 3) {
+                    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+                            argv[1], " option ?arg arg...?\"", (char*)NULL);
+                    return TCL_ERROR;
+        }
+        c = *argv[2];
+        if (c == 's' && strcmp(argv[2],"state") == 0) {
+            if (argc < 3) {
+                Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+                    argv[1], " state on|off ?volume ...? \"", (char*)NULL);
+                return TCL_ERROR;
+            }
+
+            int state;
+            if (Tcl_GetBoolean(interp, argv[3], &state) != TCL_OK) {
+                return TCL_ERROR;
+            }
+
+            int ivol;
+            if (argc < 5) {
+                for (ivol=0; ivol < n_volumes; ivol++) {
+                    if (state) {
+                        volume[ivol]->enable_outline();
+                    } else {
+                        volume[ivol]->disable_outline();
+                    }
+                }
+            } else {
+                for (int n=4; n < argc; n++) {
+                    if (Tcl_GetInt(interp, argv[n], &ivol) != TCL_OK) {
+                        return TCL_ERROR;
+                    }
+                    if (ivol < 0 || ivol > n_volumes) {
+                        Tcl_AppendResult(interp, "bad volume index \"", argv[n],
+                            "\": out of range", (char*)NULL);
+                        return TCL_ERROR;
+                    }
+                    if (state) {
+                        volume[ivol]->enable_outline();
+                    } else {
+                        volume[ivol]->disable_outline();
+                    }
+                }
+            }
+            return TCL_OK;
+        }
+        else if (c == 'c' && strcmp(argv[2],"color") == 0) {
+            if (argc < 3) {
+                Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+                    argv[1], " color {R G B} ?volume ...? \"", (char*)NULL);
+                return TCL_ERROR;
+            }
+
+            float rgb[3];
+            if (GetColor(interp, argv[3], rgb) != TCL_OK) {
+                return TCL_ERROR;
+            }
+
+            int ivol;
+            if (argc < 5) {
+                for (ivol=0; ivol < n_volumes; ivol++) {
+                    volume[ivol]->set_outline_color(rgb);
+                }
+            } else {
+                for (int n=4; n < argc; n++) {
+                    if (Tcl_GetInt(interp, argv[n], &ivol) != TCL_OK) {
+                        return TCL_ERROR;
+                    }
+                    if (ivol < 0 || ivol > n_volumes) {
+                        Tcl_AppendResult(interp, "bad volume index \"", argv[n],
+                            "\": out of range", (char*)NULL);
+                        return TCL_ERROR;
+                    }
+                    volume[ivol]->set_outline_color(rgb);
+                }
+            }
+            return TCL_OK;
+        }
+
+        Tcl_AppendResult(interp, "bad option \"", argv[2],
+            "\": should be color or state", (char*)NULL);
+        return TCL_ERROR;
+    }
+        else if (c == 's' && strcmp(argv[1],"state") == 0) {
+        if (argc < 3) {
+                    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+                            " state on|off ?volume ...?\"", (char*)NULL);
+                    return TCL_ERROR;
+        }
+
+        int state;
+            if (Tcl_GetBoolean(interp, argv[2], &state) != TCL_OK) {
+                    return TCL_ERROR;
+            }
+
+        int ivol;
+        for (int n=3; n < argc; n++) {
+                if (Tcl_GetInt(interp, argv[n], &ivol) != TCL_OK) {
+                        return TCL_ERROR;
+                }
+            if (state) {
+                volume[ivol]->enable_data();
+            } else {
+                volume[ivol]->disable_data();
+            }
+        }
+        return TCL_OK;
+    }
+
+    Tcl_AppendResult(interp, "bad option \"", argv[1],
+        "\": should be state", (char*)NULL);
+    return TCL_ERROR;
 }
 
@@ -626 +735 @@
 }
 
-
-//Switch: 
-//arg[1] = 0 : 3D rendering
-//arg[1] !=0 : 2D rendering 
+/*
+ * ----------------------------------------------------------------------
+ * FUNCTION: GetAxis()
+ *
+ * Used internally to decode an axis value from a string ("x", "y",
+ * or "z") to its index (0, 1, or 2).  Returns TCL_OK if successful,
+ * along with a value in valPtr.  Otherwise, it returns TCL_ERROR
+ * and an error message in the interpreter.
+ * ----------------------------------------------------------------------
+ */
 static int
-Switch2D3DCmd(ClientData cdata, Tcl_Interp *interp, int argc, CONST84 char *argv[])
+GetAxis(Tcl_Interp *interp, char *str, int *valPtr)
 {
-  fprintf(stderr, "switch 2D 3D rendering modes cmd\n");
-
-  double mode;
-
-  if (argc != 2) {
-    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
-                " mode\"", (char*)NULL);
+    if (strcmp(str,"x") == 0) {
+        *valPtr = 0;
+        return TCL_OK;
+    }
+    else if (strcmp(str,"y") == 0) {
+        *valPtr = 1;
+        return TCL_OK;
+    }
+    else if (strcmp(str,"z") == 0) {
+        *valPtr = 2;
+        return TCL_OK;
+    }
+    Tcl_AppendResult(interp, "bad axis \"", str,
+        "\": should be x, y, or z", (char*)NULL);
     return TCL_ERROR;
-  }
-  if (Tcl_GetDouble(interp, argv[1], &mode) != TCL_OK) {
-        return TCL_ERROR;
-  }
-
-  if(mode==0)
-    volume_mode = true;
-  else
-    volume_mode = false;
-
-  return TCL_OK;
+}
+
+/*
+ * ----------------------------------------------------------------------
+ * FUNCTION: GetColor()
+ *
+ * Used internally to decode a color value from a string ("R G B")
+ * as a list of three numbers 0-1.  Returns TCL_OK if successful,
+ * along with RGB values in valPtr.  Otherwise, it returns TCL_ERROR
+ * and an error message in the interpreter.
+ * ----------------------------------------------------------------------
+ */
+static int
+GetColor(Tcl_Interp *interp, char *str, float *rgbPtr)
+{
+    int rgbc;
+    char **rgbv;
+    if (Tcl_SplitList(interp, str, &rgbc, &rgbv) != TCL_OK) {
+        return TCL_ERROR;
+    }
+    if (rgbc != 3) {
+        Tcl_AppendResult(interp, "bad color \"", str,
+            "\": should be {R G B} as double values 0-1", (char*)NULL);
+        return TCL_ERROR;
+    }
+
+    double rval, gval, bval;
+    if (Tcl_GetDouble(interp, rgbv[0], &rval) != TCL_OK) {
+        Tcl_Free((char*)rgbv);
+        return TCL_ERROR;
+    }
+    if (Tcl_GetDouble(interp, rgbv[1], &gval) != TCL_OK) {
+        Tcl_Free((char*)rgbv);
+        return TCL_ERROR;
+    }
+    if (Tcl_GetDouble(interp, rgbv[2], &bval) != TCL_OK) {
+        Tcl_Free((char*)rgbv);
+        return TCL_ERROR;
+    }
+    Tcl_Free((char*)rgbv);
+
+    rgbPtr[0] = (float)rval;
+    rgbPtr[1] = (float)gval;
+    rgbPtr[2] = (float)bval;
+
+    return TCL_OK;
+}
+
+/*
+ * ----------------------------------------------------------------------
+ * USAGE: debug("string", ...)
+ *
+ * Use this anywhere within the package to send a debug message
+ * back to the client.  The string can have % fields as used by
+ * the printf() package.  Any remaining arguments are treated as
+ * field substitutions on that.
+ * ----------------------------------------------------------------------
+ */
+void
+debug(char *str)
+{
+    write(0, str, strlen(str));
+}
+
+void
+debug(char *str, double v1)
+{
+    char buffer[512];
+    sprintf(buffer, str, v1);
+    write(0, buffer, strlen(buffer));
+}
+
+void
+debug(char *str, double v1, double v2)
+{
+    char buffer[512];
+    sprintf(buffer, str, v1, v2);
+    write(0, buffer, strlen(buffer));
+}
+
+void
+debug(char *str, double v1, double v2, double v3)
+{
+    char buffer[512];
+    sprintf(buffer, str, v1, v2, v3);
+    write(0, buffer, strlen(buffer));
 }
 
@@ -742 +939 @@
   return TCL_OK;
 }
-
 
 
@@ -1201 +1397 @@
   volume[index] = new Volume(0.f, 0.f, 0.f, width, height, depth, 1.,  n_component, data);
   assert(volume[index]!=0);
+
+  if (n_volumes <= index) {
+    n_volumes = index+1;
+  }
 }
 
@@ -1301 +1501 @@
   if (screen_buffer) {
       delete[] screen_buffer;
-      screen_buffer = 0;
+      screen_buffer = NULL;
   }
   screen_buffer = new unsigned char[4*win_width*win_height];
-  assert(screen_buffer!=0);
+  assert(screen_buffer != NULL);
 
   //delete the current render buffer resources
@@ -1475 +1675 @@
    if (screen_buffer) {
        delete[] screen_buffer;
-       screen_buffer = 0;
+       screen_buffer = NULL;
    }
    screen_buffer = new unsigned char[4*win_width*win_height];
-   assert(screen_buffer!=0);
+   assert(screen_buffer != NULL);
 
    //create the camera with default setting
@@ -1563 +1763 @@
 
 void initTcl(){
-  interp = Tcl_CreateInterp();
-  Tcl_MakeSafe(interp);
-
-  //set camera (viewing)
-  Tcl_CreateCommand(interp, "camera", CameraCmd, (ClientData)0, (Tcl_CmdDeleteProc*)NULL);
-
-  Tcl_CreateCommand(interp, "cutplane", CutplaneCmd, (ClientData)0, (Tcl_CmdDeleteProc*)NULL);
-
-  //resize the width and height of render screen
-  Tcl_CreateCommand(interp, "screen", ScreenResizeCmd, (ClientData)0, (Tcl_CmdDeleteProc*)NULL);
+    interp = Tcl_CreateInterp();
+    Tcl_MakeSafe(interp);
+
+    // manipulate the viewpoint
+    Tcl_CreateCommand(interp, "camera", CameraCmd,
+        (ClientData)NULL, (Tcl_CmdDeleteProc*)NULL);
+
+    // turn on/off cut planes in x/y/z directions
+    Tcl_CreateCommand(interp, "cutplane", CutplaneCmd,
+        (ClientData)NULL, (Tcl_CmdDeleteProc*)NULL);
+
+    // change the size of the screen (size of picture generated)
+    Tcl_CreateCommand(interp, "screen", ScreenCmd,
+        (ClientData)NULL, (Tcl_CmdDeleteProc*)NULL);
+
+    // manipulate volume data
+    Tcl_CreateCommand(interp, "volume", VolumeCmd,
+        (ClientData)NULL, (Tcl_CmdDeleteProc*)NULL);
 
   //create new transfer function
@@ -1578 +1786 @@
   //update an existing transfer function
   Tcl_CreateCommand(interp, "tf_update", TransferFunctionUpdateCmd, (ClientData)0, (Tcl_CmdDeleteProc*)NULL);
+
 
   //create new volume
@@ -1606 +1815 @@
   glReadPixels(0, 0, win_width, win_height, GL_RGB, GL_UNSIGNED_BYTE, screen_buffer);
   assert(glGetError()==0);
-  
-  /*
-  //debug: check from the back of screen_buffer to see how far ReadPixel went
-  fprintf(stderr, "%d %d:", win_width, win_height);
-  for(int i=5*win_width*win_height-1; i>=0; i--){
-    if(screen_buffer[i] != 253){
-      fprintf(stderr, "%d\n", i);
-      i=0;
-    }
-  }
-  */
-  
-  /*
-  for(int i=0; i<win_width*win_height; i++){
-    if(screen_buffer[3*i]!=0 || screen_buffer[3*i+1]!=0 || screen_buffer[3*i+2]!=0)
-      fprintf(stderr, "(%d %d %d) ", screen_buffer[3*i], screen_buffer[3*i+1],  screen_buffer[3*i+2]);
-  }
-  */
 }
 
@@ -1686 +1877 @@
     data = tmp;
 
-    if(Tcl_Eval(interp, (char*)data.c_str()) != TCL_OK) {
-      //error to log file...
-      printf("Tcl error: %s\n", Tcl_GetStringResult(interp));
+    if (Tcl_Eval(interp, (char*)data.c_str()) != TCL_OK) {
+      std::ostringstream errmsg;
+      errmsg << "ERROR: " << Tcl_GetStringResult(interp) << std::endl;
+      write(0, errmsg.str().c_str(), errmsg.str().size());
       return;
     }