Add vk_ray_trace_indirect_scissor sample

ray_tracing_indirect_scissor/shaders/raytrace.rchit

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+#version 460
+#extension GL_EXT_ray_tracing : require
+#extension GL_EXT_nonuniform_qualifier : enable
+#extension GL_EXT_scalar_block_layout : enable
+#extension GL_GOOGLE_include_directive : enable
+#include "raycommon.glsl"
+#include "wavefront.glsl"
+
+hitAttributeEXT vec2 attribs;
+
+// clang-format off
+layout(location = 0) rayPayloadInEXT hitPayload prd;
+layout(location = 1) rayPayloadEXT bool isShadowed;
+layout(location = 2) rayPayloadEXT int hitLanternInstance;
+
+layout(binding = 0, set = 0) uniform accelerationStructureEXT topLevelAS;
+layout(binding = 2, set = 0) buffer LanternArray { LanternIndirectEntry lanterns[]; } lanterns;
+
+layout(binding = 1, set = 1, scalar) buffer MatColorBufferObject { WaveFrontMaterial m[]; } materials[];
+layout(binding = 2, set = 1, scalar) buffer ScnDesc { sceneDesc i[]; } scnDesc;
+layout(binding = 3, set = 1) uniform sampler2D textureSamplers[];
+layout(binding = 4, set = 1)  buffer MatIndexColorBuffer { int i[]; } matIndex[];
+layout(binding = 5, set = 1, scalar) buffer Vertices { Vertex v[]; } vertices[];
+layout(binding = 6, set = 1) buffer Indices { uint i[]; } indices[];
+
+// clang-format on
+
+void main()
+{
+  // Object of this instance
+  uint objId = scnDesc.i[gl_InstanceCustomIndexEXT].objId;
+
+  // Indices of the triangle
+  ivec3 ind = ivec3(indices[nonuniformEXT(objId)].i[3 * gl_PrimitiveID + 0],   //
+                    indices[nonuniformEXT(objId)].i[3 * gl_PrimitiveID + 1],   //
+                    indices[nonuniformEXT(objId)].i[3 * gl_PrimitiveID + 2]);  //
+  // Vertex of the triangle
+  Vertex v0 = vertices[nonuniformEXT(objId)].v[ind.x];
+  Vertex v1 = vertices[nonuniformEXT(objId)].v[ind.y];
+  Vertex v2 = vertices[nonuniformEXT(objId)].v[ind.z];
+
+  const vec3 barycentrics = vec3(1.0 - attribs.x - attribs.y, attribs.x, attribs.y);
+
+  // Computing the normal at hit position
+  vec3 normal = v0.nrm * barycentrics.x + v1.nrm * barycentrics.y + v2.nrm * barycentrics.z;
+  // Transforming the normal to world space
+  normal = normalize(vec3(scnDesc.i[gl_InstanceCustomIndexEXT].transfoIT * vec4(normal, 0.0)));
+
+
+  // Computing the coordinates of the hit position
+  vec3 worldPos = v0.pos * barycentrics.x + v1.pos * barycentrics.y + v2.pos * barycentrics.z;
+  // Transforming the position to world space
+  worldPos = vec3(scnDesc.i[gl_InstanceCustomIndexEXT].transfo * vec4(worldPos, 1.0));
+
+  // Vector toward the light
+  vec3  L;
+  vec3 colorIntensity = vec3(pushC.lightIntensity);
+  float lightDistance = 100000.0;
+
+  // ray direction is towards lantern, if in lantern pass.
+  if (pushC.lanternPassNumber >= 0)
+  {
+    LanternIndirectEntry lantern = lanterns.lanterns[pushC.lanternPassNumber];
+    vec3 lDir       = vec3(lantern.x, lantern.y, lantern.z) - worldPos;
+    lightDistance   = length(lDir);
+    vec3 color      = vec3(lantern.red, lantern.green, lantern.blue);
+    // Lantern light decreases linearly. Not physically accurate, but looks good
+    // and avoids a hard "edge" at the radius limit. Use a constant value
+    // if lantern debug is enabled to clearly see the covered screen rectangle.
+    float distanceFade =
+      pushC.lanternDebug != 0
+        ? 0.3
+        : max(0, (lantern.radius - lightDistance) / lantern.radius);
+    colorIntensity  = color * lantern.brightness * distanceFade;
+    L               = normalize(lDir);
+  }
+  // Non-lantern pass may have point light...
+  else if(pushC.lightType == 0)
+  {
+    vec3 lDir      = pushC.lightPosition - worldPos;
+    lightDistance  = length(lDir);
+    colorIntensity = vec3(pushC.lightIntensity / (lightDistance * lightDistance));
+    L              = normalize(lDir);
+  }
+  else  // or directional light.
+  {
+    L = normalize(pushC.lightPosition - vec3(0));
+  }
+
+  // Material of the object
+  int               matIdx = matIndex[nonuniformEXT(objId)].i[gl_PrimitiveID];
+  WaveFrontMaterial mat    = materials[nonuniformEXT(objId)].m[matIdx];
+
+
+  // Diffuse
+  vec3 diffuse = computeDiffuse(mat, L, normal);
+  if(mat.textureId >= 0)
+  {
+    uint txtId = mat.textureId + scnDesc.i[gl_InstanceCustomIndexEXT].txtOffset;
+    vec2 texCoord =
+        v0.texCoord * barycentrics.x + v1.texCoord * barycentrics.y + v2.texCoord * barycentrics.z;
+    diffuse *= texture(textureSamplers[nonuniformEXT(txtId)], texCoord).xyz;
+  }
+
+  vec3  specular    = vec3(0);
+  float attenuation = 1;
+
+  // Tracing shadow ray only if the light is visible from the surface
+  if(dot(normal, L) > 0)
+  {
+    float tMin   = 0.001;
+    float tMax   = lightDistance;
+    vec3  origin = gl_WorldRayOriginEXT + gl_WorldRayDirectionEXT * gl_HitTEXT;
+    vec3  rayDir = L;
+
+    // Ordinary shadow from the simple tutorial.
+    if (pushC.lanternPassNumber < 0) {
+      isShadowed = true;
+      uint  flags  = gl_RayFlagsTerminateOnFirstHitEXT | gl_RayFlagsOpaqueEXT
+                      | gl_RayFlagsSkipClosestHitShaderEXT;
+      traceRayEXT(topLevelAS,  // acceleration structure
+                  flags,       // rayFlags
+                  0xFF,        // cullMask
+                  0,           // sbtRecordOffset
+                  0,           // sbtRecordStride
+                  1,           // missIndex
+                  origin,      // ray origin
+                  tMin,        // ray min range
+                  rayDir,      // ray direction
+                  tMax,        // ray max range
+                  1            // payload (location = 1)
+      );
+    }
+    // Lantern shadow ray. Cast a ray towards the lantern whose lighting is being
+    // added this pass. Only the closest hit shader for lanterns will set
+    // hitLanternInstance (payload 2) to non-negative value.
+    else {
+      // Skip ray if no light would be added anyway.
+      if (colorIntensity == vec3(0)) {
+        isShadowed = true;
+      }
+      else {
+        uint flags = gl_RayFlagsOpaqueEXT;
+        hitLanternInstance = -1;
+        traceRayEXT(topLevelAS, // acceleration structure
+                    flags,      // rayFlags
+                    0xFF,       // cullMask
+                    2,          // sbtRecordOffset : lantern shadow hit groups start at index 2.
+                    0,          // sbtRecordStride
+                    2,          // missIndex       : lantern shadow miss shader is number 2.
+                    origin,     // ray origin
+                    tMin,       // ray min range
+                    rayDir,     // ray direction
+                    tMax,       // ray max range
+                    2           // payload (location = 2)
+        );
+        // Did we hit the lantern we expected?
+        isShadowed = (hitLanternInstance != pushC.lanternPassNumber);
+      }
+    }
+
+    if(isShadowed)
+    {
+      attenuation = 0.1;
+    }
+    else
+    {
+      // Specular
+      specular = computeSpecular(mat, gl_WorldRayDirectionEXT, L, normal);
+    }
+  }
+
+  prd.hitValue = colorIntensity * (attenuation * (diffuse + specular));
+  prd.additiveBlending = true;
+}