diff --git a/app-proto/inversive-display/src/main.rs b/app-proto/inversive-display/src/main.rs index c19e8ab..e3e7135 100644 --- a/app-proto/inversive-display/src/main.rs +++ b/app-proto/inversive-display/src/main.rs @@ -72,6 +72,8 @@ fn main() { sycamore::render(|| { let ctrl_x = create_signal(0.0); let ctrl_y = create_signal(0.0); + let radius_x = create_signal(1.0); + let radius_y = create_signal(1.0); let opacity = create_signal(0.5); let layer_threshold = create_signal(0.0); let display = create_node_ref(); @@ -116,12 +118,14 @@ fn main() { // controls uniform vec2 ctrl; + uniform vec2 radius; uniform float opacity; uniform int layer_threshold; // light and camera const float focal_slope = 0.3; const vec3 light_dir = normalize(vec3(2., 2., 1.)); + const float ixn_threshold = 0.005; // --- sRGB --- @@ -170,13 +174,15 @@ fn main() { // --- shading --- struct taggedFrag { + int id; vec4 color; - float depth; + vec3 pt; + vec3 normal; }; taggedFrag[2] sort(taggedFrag a, taggedFrag b) { taggedFrag[2] result; - if (a.depth < b.depth) { + if (a.pt.z > b.pt.z) { result[0] = a; result[1] = b; } else { @@ -186,7 +192,7 @@ fn main() { return result; } - taggedFrag sphere_shading(vecInv v, vec3 pt, vec3 base_color) { + taggedFrag sphere_shading(vecInv v, vec3 pt, vec3 base_color, int id) { // the expression for normal needs to be checked. it's // supposed to give the negative gradient of the lorentz // product between the impact point vector and the sphere @@ -197,7 +203,7 @@ fn main() { float incidence = dot(normal, light_dir); float illum = mix(0.4, 1.0, max(incidence, 0.0)); - return taggedFrag(vec4(illum * base_color, opacity), -pt.z); + return taggedFrag(id, vec4(illum * base_color, opacity), pt, normal); } // --- ray-casting --- @@ -228,23 +234,24 @@ fn main() { vec3 dir = vec3(focal_slope * scr, -1.); // initialize two spheres - vecInv v0 = sphere(vec3(0.5, 0.5, -5. + ctrl.x), 1.); - vecInv v1 = sphere(vec3(-0.5, -0.5, -5. + ctrl.y), 1.); + vecInv v [2]; + v[0] = sphere(vec3(0.5, 0.5, -5. + ctrl.x), radius.x); + v[1] = sphere(vec3(-0.5, -0.5, -5. + ctrl.y), radius.y); vec3 color0 = vec3(1., 0.214, 0.); vec3 color1 = vec3(0., 0.214, 1.); // cast rays through the spheres - vec2 u0 = sphere_cast(v0, dir); - vec2 u1 = sphere_cast(v1, dir); + vec2 u0 = sphere_cast(v[0], dir); + vec2 u1 = sphere_cast(v[1], dir); // shade and depth-sort the impact points taggedFrag front_hits[2] = sort( - sphere_shading(v0, u0[0] * dir, color0), - sphere_shading(v1, u1[0] * dir, color1) + sphere_shading(v[0], u0[0] * dir, color0, 0), + sphere_shading(v[1], u1[0] * dir, color1, 1) ); taggedFrag back_hits[2] = sort( - sphere_shading(v0, u0[1] * dir, color0), - sphere_shading(v1, u1[1] * dir, color1) + sphere_shading(v[0], u0[1] * dir, color0, 0), + sphere_shading(v[1], u1[1] * dir, color1, 1) ); taggedFrag middle_frags[2] = sort(front_hits[1], back_hits[0]); @@ -255,10 +262,32 @@ fn main() { frags_by_depth[2] = middle_frags[1]; frags_by_depth[3] = back_hits[1]; + // highlight intersections and cusps + for (int i = 3; i >= 1; --i) { + // intersections + taggedFrag frag0 = frags_by_depth[i]; + taggedFrag frag1 = frags_by_depth[i-1]; + float ixn_sin = length(cross(frag0.normal, frag1.normal)); + vec3 disp = frag0.pt - frag1.pt; + float ixn_dist = max( + abs(dot(frag1.normal, disp)), + abs(dot(frag0.normal, disp)) + ) / ixn_sin; + float ixn_highlight = 1. - smoothstep(2./3.*ixn_threshold, 1.5*ixn_threshold, ixn_dist); + frags_by_depth[i].color = mix(frags_by_depth[i].color, vec4(1.), ixn_highlight); + frags_by_depth[i-1].color = mix(frags_by_depth[i-1].color, vec4(1.), ixn_highlight); + + // cusps + float cusp_cos = abs(dot(dir, frag0.normal)); + float cusp_threshold = 2.*sqrt(ixn_threshold * v[frag0.id].lt.s); + float cusp_highlight = 1. - smoothstep(2./3.*cusp_threshold, 1.5*cusp_threshold, cusp_cos); + frags_by_depth[i].color = mix(frags_by_depth[i].color, vec4(1.), cusp_highlight); + } + // composite the sphere fragments vec3 color = vec3(0.); for (int i = 3; i >= layer_threshold; --i) { - if (frags_by_depth[i].depth > 0.) { + if (frags_by_depth[i].pt.z < 0.) { vec4 frag_color = frags_by_depth[i].color; color = mix(color, frag_color.rgb, frag_color.a); } @@ -288,6 +317,7 @@ fn main() { let resolution_loc = ctx.get_uniform_location(&program, "resolution"); let shortdim_loc = ctx.get_uniform_location(&program, "shortdim"); let ctrl_loc = ctx.get_uniform_location(&program, "ctrl"); + let radius_loc = ctx.get_uniform_location(&program, "radius"); let opacity_loc = ctx.get_uniform_location(&program, "opacity"); let layer_threshold_loc = ctx.get_uniform_location(&program, "layer_threshold"); @@ -319,6 +349,7 @@ fn main() { // pass the control parameters ctx.uniform2f(ctrl_loc.as_ref(), ctrl_x.get() as f32, ctrl_y.get() as f32); + ctx.uniform2f(radius_loc.as_ref(), radius_x.get() as f32, radius_y.get() as f32); ctx.uniform1f(opacity_loc.as_ref(), opacity.get() as f32); ctx.uniform1i(layer_threshold_loc.as_ref(), layer_threshold.get() as i32); @@ -346,6 +377,20 @@ fn main() { step=0.001, bind:valueAsNumber=ctrl_y ) + input( + type="range", + min=0.5, + max=1.5, + step=0.001, + bind:valueAsNumber=radius_x + ) + input( + type="range", + min=0.5, + max=1.5, + step=0.001, + bind:valueAsNumber=radius_y + ) input( type="range", max=1.0,