Add Chromium-only Blender WebEngine parity work

blender-5.2.0/intern/cycles/util/projection_inverse.h

@@ -0,0 +1,95 @@
+/* SPDX-FileCopyrightText: 2011-2022 Blender Foundation
+ *
+ * SPDX-License-Identifier: Apache-2.0 */
+
+#pragma once
+
+#include "util/defines.h"
+
+CCL_NAMESPACE_BEGIN
+
+ccl_device_forceinline bool projection_inverse_impl(ccl_private float R[4][4],
+                                                    ccl_private float M[4][4])
+{
+  /* SPDX-License-Identifier: BSD-3-Clause
+   * Adapted from code:
+   * Copyright (c) 2002, Industrial Light & Magic, a division of Lucas
+   * Digital Ltd. LLC. All rights reserved. */
+
+  /* forward elimination */
+  for (int i = 0; i < 4; i++) {
+    int pivot = i;
+    float pivotsize = M[i][i];
+
+    if (pivotsize < 0) {
+      pivotsize = -pivotsize;
+    }
+
+    for (int j = i + 1; j < 4; j++) {
+      float tmp = M[j][i];
+
+      if (tmp < 0) {
+        tmp = -tmp;
+      }
+
+      if (tmp > pivotsize) {
+        pivot = j;
+        pivotsize = tmp;
+      }
+    }
+
+    if (UNLIKELY(pivotsize == 0.0f)) {
+      return false;
+    }
+
+    if (pivot != i) {
+      for (int j = 0; j < 4; j++) {
+        float tmp;
+
+        tmp = M[i][j];
+        M[i][j] = M[pivot][j];
+        M[pivot][j] = tmp;
+
+        tmp = R[i][j];
+        R[i][j] = R[pivot][j];
+        R[pivot][j] = tmp;
+      }
+    }
+
+    for (int j = i + 1; j < 4; j++) {
+      const float f = M[j][i] / M[i][i];
+
+      for (int k = 0; k < 4; k++) {
+        M[j][k] -= f * M[i][k];
+        R[j][k] -= f * R[i][k];
+      }
+    }
+  }
+
+  /* backward substitution */
+  for (int i = 3; i >= 0; --i) {
+    float f = M[i][i];
+
+    if (UNLIKELY(f == 0.0f)) {
+      return false;
+    }
+
+    for (int j = 0; j < 4; j++) {
+      M[i][j] /= f;
+      R[i][j] /= f;
+    }
+
+    for (int j = 0; j < i; j++) {
+      f = M[j][i];
+
+      for (int k = 0; k < 4; k++) {
+        M[j][k] -= f * M[i][k];
+        R[j][k] -= f * R[i][k];
+      }
+    }
+  }
+
+  return true;
+}
+
+CCL_NAMESPACE_END