Clément Foucault
a710af2b25
This make it (theoriticaly) compatible with all supported hardware with consistent results. Also we now draw the lines with analytic anti-aliasing instead of relying on MSAA (which offers less benefits in our case). The remaining aliasing comes from edges cut in half by the mesh which is not rendered with MSAA. Hopefully this is not too much distracting and only happen if the face is almost parallel to the view.
37 lines
1.3 KiB
GLSL
37 lines
1.3 KiB
GLSL
|
|
#define M_1_SQRTPI 0.5641895835477563 /* 1/sqrt(pi) */
|
|
|
|
/**
|
|
* We want to know how much a pixel is covered by a line.
|
|
* We replace the square pixel with acircle of the same area and try to find the intersection area.
|
|
* The area we search is the circular segment. https://en.wikipedia.org/wiki/Circular_segment
|
|
* The formula for the area uses inverse trig function and is quite complexe.
|
|
* Instead, we approximate it by using the smoothstep function and a 1.05 factor to the disc radius.
|
|
**/
|
|
#define DISC_RADIUS (M_1_SQRTPI * 1.05)
|
|
#define GRID_LINE_SMOOTH_START (0.5 - DISC_RADIUS)
|
|
#define GRID_LINE_SMOOTH_END (0.5 + DISC_RADIUS)
|
|
|
|
uniform float edgeScale;
|
|
|
|
flat in vec4 finalColorOuter_f;
|
|
in vec4 finalColor_f;
|
|
in float edgeCoord_f;
|
|
|
|
out vec4 FragColor;
|
|
|
|
void main()
|
|
{
|
|
float dist = abs(edgeCoord_f) - max(sizeEdge * edgeScale - 0.5, 0.0);
|
|
float dist_outer = dist - max(sizeEdge * edgeScale, 1.0);
|
|
#if 1
|
|
float mix_w = smoothstep(GRID_LINE_SMOOTH_START, GRID_LINE_SMOOTH_END, dist);
|
|
float mix_w_outer = smoothstep(GRID_LINE_SMOOTH_START, GRID_LINE_SMOOTH_END, dist_outer);
|
|
#else
|
|
float mix_w = step(0.5, dist);
|
|
float mix_w_outer = step(0.5, dist_outer);
|
|
#endif
|
|
FragColor = mix(finalColorOuter_f, finalColor_f, 1.0 - mix_w * finalColorOuter_f.a);
|
|
FragColor.a *= 1.0 - (finalColorOuter_f.a > 0.0 ? mix_w_outer : mix_w);
|
|
}
|