I want to draw a line in OpenGL which will very often receive new points.
I want to achieve an object that draws a line behind itself:
So do I have to make an array and append all new points to it (BufferData set to GL_DYNAMIC_DRAW). And then redraw the line with glDrawArrays. Tesselation + width of stroke would be inside the vertexshader?
Or is there a better way?
The idea is to plot a point of the current position after a given delay. The time delay defines how smooth the actual line will be. Then you will have to calculate 2 new points based on the plotted positioned point which both gets multiplied by a given width.
For those plots, you also have to get the movement direction of your object to calculate the correct normals.
On the OpenGl side, you will have to initialize a fixed-sized vertex buffer
gl.glBufferData(gl.GL_ARRAY_BUFFER, 8 * self.maxPoints, None, gl.GL_DYNAMIC_DRAW) # 8 bytes 2 points = 1 plot # maxPoints amount of max plots object where you will upload every frame those 2 points (gl.glBufferSubData).
My result:
Result (Controlling with wasd):
