blender/intern/cycles/kernel/svm/svm_brightness.h
Brecht Van Lommel b6d12f11fe Fix #30004: cycles brightness/contrast node issues. The formula used did not work
very well for colors that can be outside of the 0.0..1.0 range, giving +/- infinity
results.

Now we just use a simple linear contrast factor as proposed by Paolo Sourvinos, and
clamp values to be >= 0, and also make the parameters work more in the 0..1 range
instead of the 0..100 range, to be more consistent with other nodes.
2012-02-08 17:09:30 +00:00

42 lines
1.4 KiB
C

/*
* Copyright 2011, Blender Foundation.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
CCL_NAMESPACE_BEGIN
__device void svm_node_brightness(ShaderData *sd, float *stack, uint in_color, uint out_color, uint node)
{
uint bright_offset, contrast_offset;
float3 color = stack_load_float3(stack, in_color);
decode_node_uchar4(node, &bright_offset, &contrast_offset, NULL, NULL);
float brightness = stack_load_float(stack, bright_offset);
float contrast = stack_load_float(stack, contrast_offset);
float a = 1.0f + contrast;
float b = brightness - contrast*0.5f;
color.x = max(a*color.x + b, 0.0f);
color.y = max(a*color.y + b, 0.0f);
color.z = max(a*color.z + b, 0.0f);
if (stack_valid(out_color))
stack_store_float3(stack, out_color, color);
}
CCL_NAMESPACE_END