[1.20.4] How to draw a line between two blocks in the game world?

[NoName_]

I have been researching existing topics related to this question for a while, but unfortunately, they are all outdated. I tried to understand the principle of such rendering from the debug code (displaying the view direction, displaying hitboxes), but to no avail.

In one of the topics (Forum link) where this question was discussed, there was a reference to "some really old code, but has the relevant math" (GitHub link), which I tried to update (spoiler below), but it didn't yield any results. Nothing gets rendered.

Does anyone know of projects that use custom rendering of simple shapes (lines/squares/circles) so that I can investigate their source code? Or can anyone help fix existing code? In general, any information on this matter would be helpful)
 

Spoiler

    private void drawLine(Vec3 blockA, Vec3 blockB) {
        Tesselator tesselator = Tesselator.getInstance();
        BufferBuilder builder = tesselator.getBuilder();
        builder.begin(VertexFormat.Mode.QUADS, DefaultVertexFormat.POSITION);

        Vec3 recLong = blockA.subtract(blockB);
        var perpendicular = new Vec3(recLong.z, recLong.y, -recLong.x);
        perpendicular = perpendicular.normalize();

        float width = 1f / 16f;
        
        var r1 = new Vec3(blockA.x + perpendicular.x * width, blockA.y - 0.01, blockA.z + perpendicular.z * width);
        var r2 = new Vec3(blockA.x - perpendicular.x * width, blockA.y - 0.01, blockA.z - perpendicular.z * width);

        var r3 = new Vec3(blockB.x + perpendicular.x * width, blockB.y + 0.75, blockB.z + perpendicular.z * width);
        var r4 = new Vec3(blockB.x - perpendicular.x * width, blockB.y + 0.75, blockB.z - perpendicular.z * width);

        createVertexForPoint(builder, r1);
        createVertexForPoint(builder, r3);
        createVertexForPoint(builder, r4);
        createVertexForPoint(builder, r2);

        tesselator.end();
    }

    private void createVertexForPoint(BufferBuilder builder, Vec3 r1) {
        builder.vertex(r1.x + 0.5, r1.y + 1, r1.z + 0.5).color(1F, 0, 0, 1F).endVertex();
    }

 

More information about the code:
The code is called for two blocks located on the same level. The initiation of this code call is through the RenderLevelStageEvent event, where the getStage method returns the value AFTER_TRIPWIRE_BLOCKS. The drawLine method is precisely called on the necessary blocks, and there are no error messages during this process.

Edited March 19 by NoName_