ahmet kizilay

I am sending opengl commands to jit.gl.sketch object from javascript. I would like to draw the same pattern at different positions, so I refactored my code in a method. The problem is that I call the same function "twice" with the same parameters, and I get one pattern translated by 0.5 on the x-axis.

When I remove the code for the yellow line, it seems to be working. However, I could not think of a reason why it should yield a incorrect result with it.

// outlet(0, "glmatrixmode", "modelview");

function draw_unit(globCell, localCell) {

outlet(0, "gltranslate", globCell[0], globCell[1], globCell[2]); // global transform

outlet(0, "gltranslate", -0.5, localCell[0], 0);

outlet(0, "framecircle", 0.1, angle, angle+arc);

outlet(0, "gltranslate", 0.5, localCell[1], 0);

    outlet(0, "framecircle", 0.1, angle, angle+arc);

outlet(0, "glvertex", -0.5, localCell[0], 0);

outlet(0, "glvertex", 0.5, localCell[1], 0);

Hello,
I am sending opengl commands to jit.gl.sketch object from javascript. I would like to draw the same pattern at different positions, so I refactored my code in a method. The problem is that I call the same function "twice" with the same parameters, and I get one pattern translated by 0.5 on the x-axis.

When I remove the code for the yellow line, it seems to be working. However, I could not think of a reason why it should yield a incorrect result with it. 

function bang() {
    outlet(0, "reset");
//    outlet(0, "glmatrixmode", "modelview");

	draw_unit([0, 0, 0], [0,0]);
	draw_unit([0, 0, 0], [0,0]);
}

function draw_unit(globCell, localCell) {
	outlet(0, "glpushmatrix");
    outlet(0, "glcolor", 1, 1, 1);
    outlet(0, "gltranslate", globCell[0], globCell[1], globCell[2]); // global transform

    outlet(0, "glpushmatrix");
    outlet(0, "gltranslate", -0.5, localCell[0], 0);
    outlet(0, "framecircle", 0.1, angle, angle+arc);
    outlet(0, "glpopmatrix"); 

    outlet(0, "glpushmatrix");
    outlet(0, "gltranslate", 0.5, localCell[1], 0);
	outlet(0, "framecircle", 0.1, angle, angle+arc);
    outlet(0, "glpopmatrix");

    outlet(0, "glpushmatrix");
    outlet(0, "glcolor", 1, 0, 0);
    outlet(0, "framecircle", 0.4);
    outlet(0, "glpopmatrix");

    outlet(0, "glpushmatrix");
    outlet(0, "glbegin", "lines");
    outlet(0, "glvertex", -0.5, localCell[0], 0);
    outlet(0, "glvertex", 0.5, localCell[1], 0);
    outlet(0, "glend");
    outlet(0, "glpopmatrix");

jit-gl-sketch-inconsistent-translate-rendering

won't be able to help without seeing the full javascript.

here is the full JS. thanks in advance...

function bang() {
    outlet(0, "reset");

	draw_unit([0, 0, 0], [0,0]);
	draw_unit([0, 0, 0], [0,0]);

    outlet(0, "glpushmatrix");
    outlet(0, "gltranslate", 0.5, localCell[1], 0);
    outlet(0, "framecircle", 0.1, angle, angle+arc);
    outlet(0, "glpopmatrix");

anyone would like to comment on this, please?

ok, it looks like you need to use the "moveto" message at the start of your draw_unit function.

var arc = 300, angle = 0;

function bang() {
    outlet(0, "reset");
    draw_unit([0, 0, 0], [0,0]);
    draw_unit([0.25, 0.25, 0], [0,0]);
}

function draw_unit(globCell, localCell) {
    outlet(0, "glcolor", 1, 1, 1);
    outlet(0, "moveto", globCell[0], globCell[1], globCell[2]); // global transform

    outlet(0, "glpushmatrix");
    outlet(0, "gltranslate", -0.5, localCell[0], 0);
    outlet(0, "framecircle", 0.1, angle, angle+arc);
    outlet(0, "glpopmatrix");

    outlet(0, "glpushmatrix");
    outlet(0, "gltranslate", 0.5, localCell[1], 0);
    outlet(0, "framecircle", 0.1, angle, angle+arc);
    outlet(0, "glpopmatrix");

    outlet(0, "glcolor", 1, 0, 0);
    outlet(0, "framecircle", 0.4);

    outlet(0, "glcolor", 1, 1, 0);
    outlet(0, "gltranslate", globCell[0], globCell[1], globCell[2]);
    outlet(0, "glbegin", "lines");
    outlet(0, "glvertex", -0.5, localCell[0], 0);
    outlet(0, "glvertex", 0.5, localCell[1], 0);
    outlet(0, "glend");
}


ok, it looks like you need to use the "moveto" message at the start of your draw_unit function.
not entirely sure why that is.
the following works for me

var arc = 300, angle = 0;

function bang() {
	outlet(0, "reset");
	draw_unit([0, 0, 0], [0,0]);
	draw_unit([0.25, 0.25, 0], [0,0]);
}

function draw_unit(globCell, localCell) {
	outlet(0, "glcolor", 1, 1, 1);
	outlet(0, "moveto", globCell[0], globCell[1], globCell[2]); // global transform

	outlet(0, "glpushmatrix");
	outlet(0, "gltranslate", -0.5, localCell[0], 0);
	outlet(0, "framecircle", 0.1, angle, angle+arc);
	outlet(0, "glpopmatrix");

	outlet(0, "glpushmatrix");
	outlet(0, "gltranslate", 0.5, localCell[1], 0);
	outlet(0, "framecircle", 0.1, angle, angle+arc);
	outlet(0, "glpopmatrix");

	outlet(0, "glcolor", 1, 0, 0);
	outlet(0, "framecircle", 0.4);

	outlet(0, "glcolor", 1, 1, 0);
	outlet(0, "gltranslate", globCell[0], globCell[1], globCell[2]);
	outlet(0, "glbegin", "lines");
	outlet(0, "glvertex", -0.5, localCell[0], 0);
	outlet(0, "glvertex", 0.5, localCell[1], 0);
	outlet(0, "glend");
}


jit.gl.sketch inconsistent translate rendering