diff options
Diffstat (limited to 'intern/cycles/kernel/shaders/node_ramp_util.h')
-rw-r--r-- | intern/cycles/kernel/shaders/node_ramp_util.h | 89 |
1 files changed, 89 insertions, 0 deletions
diff --git a/intern/cycles/kernel/shaders/node_ramp_util.h b/intern/cycles/kernel/shaders/node_ramp_util.h new file mode 100644 index 00000000000..917fb65c6df --- /dev/null +++ b/intern/cycles/kernel/shaders/node_ramp_util.h @@ -0,0 +1,89 @@ +/* + * Copyright 2011-2013 Blender Foundation + * + * 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. + */ + +/* NOTE: svm_ramp.h, svm_ramp_util.h and node_ramp_util.h must stay consistent */ + +color rgb_ramp_lookup(color ramp[], float at, int interpolate, int extrapolate) +{ + float f = at; + int table_size = arraylength(ramp); + + if ((f < 0.0 || f > 1.0) && extrapolate) { + color t0, dy; + if (f < 0.0) { + t0 = ramp[0]; + dy = t0 - ramp[1]; + f = -f; + } + else { + t0 = ramp[table_size - 1]; + dy = t0 - ramp[table_size - 2]; + f = f - 1.0; + } + return t0 + dy * f * (table_size - 1); + } + + f = clamp(at, 0.0, 1.0) * (table_size - 1); + + /* clamp int as well in case of NaN */ + int i = (int)f; + if (i < 0) i = 0; + if (i >= table_size) i = table_size - 1; + float t = f - (float)i; + + color result = ramp[i]; + + if (interpolate && t > 0.0) + result = (1.0 - t) * result + t * ramp[i + 1]; + + return result; +} + +float rgb_ramp_lookup(float ramp[], float at, int interpolate, int extrapolate) +{ + float f = at; + int table_size = arraylength(ramp); + + if ((f < 0.0 || f > 1.0) && extrapolate) { + float t0, dy; + if (f < 0.0) { + t0 = ramp[0]; + dy = t0 - ramp[1]; + f = -f; + } + else { + t0 = ramp[table_size - 1]; + dy = t0 - ramp[table_size - 2]; + f = f - 1.0; + } + return t0 + dy * f * (table_size - 1); + } + + f = clamp(at, 0.0, 1.0) * (table_size - 1); + + /* clamp int as well in case of NaN */ + int i = (int)f; + if (i < 0) i = 0; + if (i >= table_size) i = table_size - 1; + float t = f - (float)i; + + float result = ramp[i]; + + if (interpolate && t > 0.0) + result = (1.0 - t) * result + t * ramp[i + 1]; + + return result; +} |