init

shaders/lua_native_terrain.glsl

@@ -0,0 +1,15 @@
+// Same half-cell samples and last-free result as the engine's CPU raytrace.
+// ngp_solid_at supplies terrain only; rigid bodies are outside this API.
+bool ngp_solid_at(vec2 position);
+vec3 ngp_surface(vec2 start, vec2 end) {
+    float distance=length(end-start);
+    if(isnan(distance)||isinf(distance)||distance>512.0) return vec3(start, -1.0);
+    int steps=max(1,int(ceil(distance*2.0)));
+    vec2 previous=start;
+    for(int k=1;k<=steps;++k) {
+        vec2 point=start+(end-start)*float(k)/float(steps);
+        if(ngp_solid_at(point))return vec3(previous,1.0);
+        previous=point;
+    }
+    return vec3(end,0.0);
+}