9cfc7967dd
* Replace license text in headers with SPDX identifiers. * Remove specific license info from outdated readme.txt, instead leave details to the source files. * Add list of SPDX license identifiers used, and corresponding license texts. * Update copyright dates while we're at it. Ref D14069, T95597
45 lines
1.3 KiB
C
45 lines
1.3 KiB
C
/* SPDX-License-Identifier: BSD-3-Clause
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*
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* Adapted from Open Shading Language
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* Copyright (c) 2009-2010 Sony Pictures Imageworks Inc., et al.
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* All Rights Reserved.
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*
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* Modifications Copyright 2011-2022 Blender Foundation. */
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#pragma once
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CCL_NAMESPACE_BEGIN
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/* Wavelength to RGB */
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ccl_device_noinline void svm_node_wavelength(KernelGlobals kg,
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ccl_private ShaderData *sd,
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ccl_private float *stack,
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uint wavelength,
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uint color_out)
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{
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float lambda_nm = stack_load_float(stack, wavelength);
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float ii = (lambda_nm - 380.0f) * (1.0f / 5.0f); // scaled 0..80
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int i = float_to_int(ii);
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float3 color;
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if (i < 0 || i >= 80) {
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color = make_float3(0.0f, 0.0f, 0.0f);
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}
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else {
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ii -= i;
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ccl_constant float *c = cie_colour_match[i];
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color = interp(make_float3(c[0], c[1], c[2]), make_float3(c[3], c[4], c[5]), ii);
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}
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color = xyz_to_rgb(kg, color);
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color *= 1.0f / 2.52f; // Empirical scale from lg to make all comps <= 1
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/* Clamp to zero if values are smaller */
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color = max(color, make_float3(0.0f, 0.0f, 0.0f));
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stack_store_float3(stack, color_out, color);
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}
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CCL_NAMESPACE_END
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