Hi,
Was wondering how I draw a stroke in 3D space using the mouse.
Currently I draw using gl_Line_Strip(with my own coding to make it follow the mouse motion path). The problem now is that I do not want to have only a line, because a line gives me only the x,y coordinates of every point through the line, but what I want is to have a stroke.
For example, the stroke is of 5 pixels wide and I draw it across 100 pixels. I want to have all the x,y coordinates within this 5*100 area.How to I achieve that.
attached is the picture showing the line drawn in red.What I want is that the width of the line to be increased, and want to have all the points in the area.
Below is the code of the draw stroke method(current its just line). the draw drawstroke is called in display(), called by mouse drag events.
public void drawStroke(GL gl) {
if (startX == 999f) {
startX = tmpX;
startY = tmpY;
}
endX = (float) wcoord[0];
endY = (float) wcoord[1];
gl.glLineWidth(2.0f);
gl.glBegin(GL.GL_LINE_STRIP);
gl.glVertex3f(startX, startY,3.0f);
gl.glVertex3f(endX, endY,3.0f);
//System.out.println("Line draw at: "+ startX +", "+startY);
startX = endX;
startY = endY;
gl.glEnd();
gl.glLineWidth(1.0f);
gl.glFlush();
}
public void calObjectCoor(GL gl,float mousex,float mousey,float z) {
float x = mousex, y = mousey;
gl.glGetIntegerv(GL.GL_VIEWPORT, viewport,0);
gl.glGetDoublev(GL.GL_MODELVIEW_MATRIX, mvmatrix,0);
gl.glGetDoublev(GL.GL_PROJECTION_MATRIX, projmatrix, 0);
/* note viewport[3] is height of window in pixels */
realy = viewport[3] - (int) y;
glu.gluUnProject((double) x, (double) realy, z, //
mvmatrix, 0,
projmatrix, 0,
viewport, 0,
wcoord, 0);
}
Actually Im working on the siggraph paper(modelling by examples). Any form of help on this topic would be greatly appreciated.