blender/intern/cycles/kernel/svm/svm_ramp.h
Sergey Sharybin c81e6ffdf9 Fix T46915: Non-intuitive behavior of Vector Curve Mapping node
Vector mapping node was doing some weird mapping of both original and mapped
coordinates. Mapping of original coordinates was caused by the clamping nature
of the LUT generated from the node. Mapping of the mapped value again was quite
totally obscure -- one needed to constantly keep in mind that actual value will
be scaled up and moved down.

This commit makes it so values in the vector curve mapping are always absolute.
In fact, it is now behaving quite the same as RGB curve mapping node and the
code could be de-duplicated. Keeping the code duplicated for a bit so it's more
clear what exact parts of the node changed.

Reviewers: brecht

Subscribers: bassamk

Differential Revision: https://developer.blender.org/D1672
2015-12-31 20:40:22 +05:00

133 lines
4.0 KiB
C

/*
* 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.
*/
#ifndef __SVM_RAMP_H__
#define __SVM_RAMP_H__
CCL_NAMESPACE_BEGIN
ccl_device float4 rgb_ramp_lookup(KernelGlobals *kg,
int offset,
float f,
bool interpolate,
bool extrapolate)
{
if((f < 0.0f || f > 1.0f) && extrapolate) {
float4 t0, dy;
if(f < 0.0f) {
t0 = fetch_node_float(kg, offset);
dy = t0 - fetch_node_float(kg, offset + 1);
f = -f;
}
else {
t0 = fetch_node_float(kg, offset + RAMP_TABLE_SIZE - 1);
dy = t0 - fetch_node_float(kg, offset + RAMP_TABLE_SIZE - 2);
f = f - 1.0f;
}
return t0 + dy * f * (RAMP_TABLE_SIZE-1);
}
f = saturate(f)*(RAMP_TABLE_SIZE-1);
/* clamp int as well in case of NaN */
int i = clamp(float_to_int(f), 0, RAMP_TABLE_SIZE-1);
float t = f - (float)i;
float4 a = fetch_node_float(kg, offset+i);
if(interpolate && t > 0.0f)
a = (1.0f - t)*a + t*fetch_node_float(kg, offset+i+1);
return a;
}
ccl_device void svm_node_rgb_ramp(KernelGlobals *kg, ShaderData *sd, float *stack, uint4 node, int *offset)
{
uint fac_offset, color_offset, alpha_offset;
uint interpolate = node.z;
decode_node_uchar4(node.y, &fac_offset, &color_offset, &alpha_offset, NULL);
float fac = stack_load_float(stack, fac_offset);
float4 color = rgb_ramp_lookup(kg, *offset, fac, interpolate, false);
if(stack_valid(color_offset))
stack_store_float3(stack, color_offset, float4_to_float3(color));
if(stack_valid(alpha_offset))
stack_store_float(stack, alpha_offset, color.w);
*offset += RAMP_TABLE_SIZE;
}
ccl_device void svm_node_rgb_curves(KernelGlobals *kg, ShaderData *sd, float *stack, uint4 node, int *offset)
{
uint fac_offset, color_offset, out_offset;
decode_node_uchar4(node.y,
&fac_offset,
&color_offset,
&out_offset,
NULL);
float fac = stack_load_float(stack, fac_offset);
float3 color = stack_load_float3(stack, color_offset);
const float min_x = __int_as_float(node.z),
max_x = __int_as_float(node.w);
const float range_x = max_x - min_x;
color = (color - make_float3(min_x, min_x, min_x)) / range_x;
float r = rgb_ramp_lookup(kg, *offset, color.x, true, true).x;
float g = rgb_ramp_lookup(kg, *offset, color.y, true, true).y;
float b = rgb_ramp_lookup(kg, *offset, color.z, true, true).z;
color = (1.0f - fac)*color + fac*make_float3(r, g, b);
stack_store_float3(stack, out_offset, color);
*offset += RAMP_TABLE_SIZE;
}
ccl_device void svm_node_vector_curves(KernelGlobals *kg, ShaderData *sd, float *stack, uint4 node, int *offset)
{
uint fac_offset, color_offset, out_offset;
decode_node_uchar4(node.y,
&fac_offset,
&color_offset,
&out_offset,
NULL);
float fac = stack_load_float(stack, fac_offset);
float3 color = stack_load_float3(stack, color_offset);
const float min_x = __int_as_float(node.z),
max_x = __int_as_float(node.w);
const float range_x = max_x - min_x;
color = (color - make_float3(min_x, min_x, min_x)) / range_x;
float r = rgb_ramp_lookup(kg, *offset, color.x, true, true).x;
float g = rgb_ramp_lookup(kg, *offset, color.y, true, true).y;
float b = rgb_ramp_lookup(kg, *offset, color.z, true, true).z;
color = (1.0f - fac)*color + fac*make_float3(r, g, b);
stack_store_float3(stack, out_offset, color);
*offset += RAMP_TABLE_SIZE;
}
CCL_NAMESPACE_END
#endif /* __SVM_RAMP_H__ */