Begin work on `custom30` world

Add vertex colors

1 files changed, 157 insertions, 0 deletions

diff --git a/custom30.cginc b/custom30.cginc
new file mode 100644
index 0000000..38fe2c2
--- /dev/null
+++ b/custom30.cginc
@@ -0,0 +1,157 @@
+#ifndef __CUSTOM30_INC
+#define __CUSTOM30_INC
+
+#include "globals.cginc"
+#include "quilez.cginc"
+#include "interpolators.cginc"
+
+#if defined(_CUSTOM30)
+
+#define CUSTOM30_MAX_STEPS 30
+
+struct Custom30Output {
+  float3 objPos;
+  float3 normal;
+  float depth;
+};
+
+float3 GetFragToOrigin(v2f i) {
+  // Vector from fragment to origin
+  return float3(-1, 1, 1) * (i.color * 2.0f - 1.0f) / i.color.a;
+}
+
+float cut_with_box(float3 p, float d, float3 box_size) {
+  float2 pp_xy = p.xy;
+  float2 pp_xz = p.xz;
+  float2 pp_yz = p.yz;
+
+  // Rotate by 45 degrees
+  float c = 0.70710678;
+  float s = 0.70710678;
+  pp_xy = float2(c * p.x - s * p.y, s * p.x + c * p.y);
+  d = max(d, distance_from_box(float3(pp_xy, p.z), box_size));
+
+  pp_xz = float2(c * p.x - s * p.z, s * p.x + c * p.z);
+  d = max(d, distance_from_box(float3(pp_xz, p.y), box_size));
+
+  pp_yz = float2(c * p.y - s * p.z, s * p.y + c * p.z);
+  d = max(d, distance_from_box(float3(pp_yz, p.x), box_size));
+
+  return d;
+}
+
+#if defined(_CUSTOM30_BASICCUBE)
+float BasicCube_map(float3 p) {
+  float box_d = distance_from_box_frame(p, .995, .15);
+  float core_d = distance_from_box(p, 0.95);
+  float d = min(box_d, core_d);
+
+  d = cut_with_box(p, d, 1.3);
+
+  return d;
+}
+
+float3 BasicCube_normal(float3 p) {
+  float epsilon = 1E-3;
+  float center_d = BasicCube_map(p);
+  float3 n = float3(
+    BasicCube_map(p + float3(epsilon, 0, 0)) - center_d,
+    BasicCube_map(p + float3(0, epsilon, 0)) - center_d,
+    BasicCube_map(p + float3(0, 0, epsilon)) - center_d);
+  return normalize(n);
+}
+
+Custom30Output BasicCube(v2f i) {
+  float3 objSpaceCameraPos = mul(unity_WorldToObject, float4(_WorldSpaceCameraPos, 1.0));
+
+  float3 frag_to_origin = GetFragToOrigin(i);
+
+  float3 ro = -frag_to_origin;
+  float3 rd = normalize(i.objPos - objSpaceCameraPos);
+
+  float d;
+  float d_acc = 0;
+  float epsilon = 5E-3;
+  // 1.73... = sqrt(3)
+  // our cube has an edge length of 2, so mult by 2
+  float max_d = 1.73205081f * 2.0f;
+  [loop]
+  for (uint ii = 0; ii < CUSTOM30_MAX_STEPS; ++ii) {
+    float3 p = ro + rd * d_acc;
+    d = BasicCube_map(p);
+    d_acc += d;
+    if (d < epsilon) break;
+    if (d_acc > max_d) break;
+  }
+
+  Custom30Output o;
+  clip(epsilon - d);
+  float3 objPos = ro + rd * d_acc;
+  o.objPos = objPos;
+  // Transform from SDF space back to object space
+  float3 objSpacePos = objPos + (i.objPos + frag_to_origin);
+  float4 clipPos = UnityObjectToClipPos(objSpacePos);
+  o.depth = clipPos.z / clipPos.w;
+  o.normal = BasicCube_normal(objPos);
+  return o;
+}
+#endif
+
+#if defined(_CUSTOM30_BASICWEDGE)
+float BasicWedge_map(float3 p) {
+  float box_d = distance_from_box(p, float3(1, 1, 1));
+  float cut_plane_d = distance_from_plane(p - float3(0, 0, 0), -normalize(float3(1, 0, 1)), 0);
+
+  float d = op_sub(box_d, cut_plane_d);
+  //d = cut_with_box(p, d, 1.3);
+  return d;
+}
+
+float3 BasicWedge_normal(float3 p) {
+  float epsilon = 1E-3;
+  float center_d = BasicWedge_map(p);
+  float3 n = float3(
+    BasicWedge_map(p + float3(epsilon, 0, 0)) - center_d,
+    BasicWedge_map(p + float3(0, epsilon, 0)) - center_d,
+    BasicWedge_map(p + float3(0, 0, epsilon)) - center_d);
+  return normalize(n);
+}
+
+Custom30Output BasicWedge(v2f i) {
+  float3 objSpaceCameraPos = mul(unity_WorldToObject, float4(_WorldSpaceCameraPos, 1.0));
+
+  float3 frag_to_origin = GetFragToOrigin(i);
+
+  float3 ro = -frag_to_origin;
+  float3 rd = normalize(i.objPos - objSpaceCameraPos);
+
+  float d;
+  float d_acc = 0;
+  float epsilon = 5E-3;
+  // 1.73... = sqrt(3)
+  // our cube has an edge length of 2, so mult by 2
+  float max_d = 1.73205081f * 2.0f;
+  [loop]
+  for (uint ii = 0; ii < CUSTOM30_MAX_STEPS; ++ii) {
+    float3 p = ro + rd * d_acc;
+    d = BasicWedge_map(p);
+    d_acc += d;
+    if (d < epsilon) break;
+    if (d_acc > max_d) break;
+  }
+
+  Custom30Output o;
+  clip(epsilon - d);
+  float3 objPos = ro + rd * d_acc;
+  o.objPos = objPos;
+  // Transform from SDF space back to object space
+  float3 objSpacePos = objPos + (i.objPos + frag_to_origin);
+  float4 clipPos = UnityObjectToClipPos(objSpacePos);
+  o.depth = clipPos.z / clipPos.w;
+  o.normal = BasicWedge_normal(objPos);
+  return o;
+}
+#endif
+
+#endif  // _CUSTOM30
+#endif  // __CUSTOM30_INC