Partially working switch to having a vcounter and hslot counter in the context rather than trying to derive them from the cycle count. This should allow for more accurate handling of mid screen mode switches. Interrupt timing is broken currently though

#version 110

attribute vec2 pos;
varying vec2 texcoord;
uniform float width;

void main()
{
	gl_Position = vec4(pos, 0.0, 1.0);
	texcoord = sign(pos) * vec2(width/1024.0, 240.0/-512.0) + vec2(width/1024.0, 240.0/512.0);
}