35 lines
1.2 KiB
GLSL
35 lines
1.2 KiB
GLSL
// See IntersectionUtils.glsl for the definitions of Ray, RayShapeIntersection,
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// NO_HIT, Intersections
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/* Box defines (set in Scene/VoxelBoxShape.js)
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#define BOX_INTERSECTION_INDEX ### // always 0
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*/
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uniform sampler2D u_renderBoundPlanesTexture;
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RayShapeIntersection intersectBoundPlanes(in Ray ray) {
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vec4 lastEntry = vec4(ray.dir, -INF_HIT);
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vec4 firstExit = vec4(-ray.dir, +INF_HIT);
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for (int i = 0; i < 6; i++) {
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vec4 boundPlane = getBoundPlane(u_renderBoundPlanesTexture, i);
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vec4 intersection = intersectPlane(ray, boundPlane);
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if (dot(ray.dir, boundPlane.xyz) < 0.0) {
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lastEntry = intersection.w > lastEntry.w ? intersection : lastEntry;
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} else {
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firstExit = intersection.w < firstExit.w ? intersection: firstExit;
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}
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}
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if (lastEntry.w < firstExit.w) {
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return RayShapeIntersection(lastEntry, firstExit);
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} else {
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return RayShapeIntersection(vec4(-ray.dir, NO_HIT), vec4(ray.dir, NO_HIT));
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}
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}
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void intersectShape(in Ray rayUV, in Ray rayEC, inout Intersections ix)
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{
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RayShapeIntersection intersection = intersectBoundPlanes(rayEC);
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setShapeIntersection(ix, BOX_INTERSECTION_INDEX, intersection);
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}
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