90 lines
2.1 KiB
C
90 lines
2.1 KiB
C
/*
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* Copyright 2011-2013 Blender Foundation
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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/* NOTE: svm_ramp.h, svm_ramp_util.h and node_ramp_util.h must stay consistent */
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color rgb_ramp_lookup(color ramp[], float at, int interpolate, int extrapolate)
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{
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float f = at;
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int table_size = arraylength(ramp);
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if ((f < 0.0 || f > 1.0) && extrapolate) {
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color t0, dy;
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if (f < 0.0) {
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t0 = ramp[0];
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dy = t0 - ramp[1];
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f = -f;
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}
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else {
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t0 = ramp[table_size - 1];
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dy = t0 - ramp[table_size - 2];
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f = f - 1.0;
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}
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return t0 + dy * f * (table_size - 1);
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}
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f = clamp(at, 0.0, 1.0) * (table_size - 1);
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/* clamp int as well in case of NaN */
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int i = (int)f;
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if (i < 0) i = 0;
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if (i >= table_size) i = table_size - 1;
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float t = f - (float)i;
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color result = ramp[i];
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if (interpolate && t > 0.0)
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result = (1.0 - t) * result + t * ramp[i + 1];
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return result;
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}
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float rgb_ramp_lookup(float ramp[], float at, int interpolate, int extrapolate)
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{
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float f = at;
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int table_size = arraylength(ramp);
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if ((f < 0.0 || f > 1.0) && extrapolate) {
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float t0, dy;
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if (f < 0.0) {
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t0 = ramp[0];
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dy = t0 - ramp[1];
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f = -f;
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}
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else {
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t0 = ramp[table_size - 1];
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dy = t0 - ramp[table_size - 2];
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f = f - 1.0;
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}
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return t0 + dy * f * (table_size - 1);
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}
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f = clamp(at, 0.0, 1.0) * (table_size - 1);
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/* clamp int as well in case of NaN */
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int i = (int)f;
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if (i < 0) i = 0;
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if (i >= table_size) i = table_size - 1;
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float t = f - (float)i;
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float result = ramp[i];
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if (interpolate && t > 0.0)
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result = (1.0 - t) * result + t * ramp[i + 1];
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return result;
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}
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