initial work to split into dart_filament and flutter_filament

flutter_filament/windows/include/filament/ibl/CubemapIBL.h

@@ -0,0 +1,91 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef IBL_CUBEMAPIBL_H
+#define IBL_CUBEMAPIBL_H
+
+#include <math/vec3.h>
+
+#include <utils/Slice.h>
+#include <utils/compiler.h>
+
+#include <vector>
+
+#include <stdint.h>
+#include <stddef.h>
+
+namespace utils {
+class JobSystem;
+} // namespace utils
+
+namespace filament {
+namespace ibl {
+
+class Cubemap;
+class Image;
+
+/**
+ * Generates cubemaps for the IBL.
+ */
+class UTILS_PUBLIC CubemapIBL {
+public:
+    typedef void (*Progress)(size_t, float, void*);
+
+    /**
+     * Computes a roughness LOD using prefiltered importance sampling GGX
+     *
+     * @param dst               the destination cubemap
+     * @param levels            a list of prefiltered lods of the source environment
+     * @param linearRoughness   roughness
+     * @param maxNumSamples     number of samples for importance sampling
+     * @param updater           a callback for the caller to track progress
+     */
+    static void roughnessFilter(
+            utils::JobSystem& js, Cubemap& dst, const utils::Slice<Cubemap>& levels,
+            float linearRoughness, size_t maxNumSamples, math::float3 mirror, bool prefilter,
+            Progress updater = nullptr, void* userdata = nullptr);
+
+    static void roughnessFilter(
+            utils::JobSystem& js, Cubemap& dst, const std::vector<Cubemap>& levels,
+            float linearRoughness, size_t maxNumSamples, math::float3 mirror, bool prefilter,
+            Progress updater = nullptr, void* userdata = nullptr);
+
+    //! Computes the "DFG" term of the "split-sum" approximation and stores it in a 2D image
+    static void DFG(utils::JobSystem& js, Image& dst, bool multiscatter, bool cloth);
+
+    /**
+     * Computes the diffuse irradiance using prefiltered importance sampling GGX
+     *
+     * @note Usually this is done using spherical harmonics instead.
+     *
+     * @param dst               the destination cubemap
+     * @param levels            a list of prefiltered lods of the source environment
+     * @param maxNumSamples     number of samples for importance sampling
+     * @param updater           a callback for the caller to track progress
+     *
+     * @see CubemapSH
+     */
+    static void diffuseIrradiance(utils::JobSystem& js, Cubemap& dst, const std::vector<Cubemap>& levels,
+            size_t maxNumSamples = 1024, Progress updater = nullptr, void* userdata = nullptr);
+
+    // for debugging. ignore.
+    static void brdf(utils::JobSystem& js, Cubemap& dst, float linearRoughness);
+};
+
+} // namespace ibl
+} // namespace filament
+
+#endif /* IBL_CUBEMAPIBL_H */