forked from bartvdbraak/blender
142 lines
3.9 KiB
C
142 lines
3.9 KiB
C
/*
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* Copyright 2011, Blender Foundation.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software Foundation,
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* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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*/
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CCL_NAMESPACE_BEGIN
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#ifdef __HAIR__
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/* curve attributes */
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__device float curve_attribute_float(KernelGlobals *kg, const ShaderData *sd, AttributeElement elem, int offset, float *dx, float *dy)
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{
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if(elem == ATTR_ELEMENT_CURVE) {
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#ifdef __RAY_DIFFERENTIALS__
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if(dx) *dx = 0.0f;
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if(dy) *dy = 0.0f;
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#endif
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return kernel_tex_fetch(__attributes_float, offset + sd->prim);
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}
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else if(elem == ATTR_ELEMENT_CURVE_KEY) {
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float4 curvedata = kernel_tex_fetch(__curves, sd->prim);
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int k0 = __float_as_int(curvedata.x) + sd->segment;
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int k1 = k0 + 1;
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float f0 = kernel_tex_fetch(__attributes_float, offset + k0);
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float f1 = kernel_tex_fetch(__attributes_float, offset + k1);
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#ifdef __RAY_DIFFERENTIALS__
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if(dx) *dx = sd->du.dx*(f1 - f0);
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if(dy) *dy = 0.0f;
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#endif
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return (1.0f - sd->u)*f0 + sd->u*f1;
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}
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else {
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#ifdef __RAY_DIFFERENTIALS__
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if(dx) *dx = 0.0f;
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if(dy) *dy = 0.0f;
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#endif
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return 0.0f;
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}
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}
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__device float3 curve_attribute_float3(KernelGlobals *kg, const ShaderData *sd, AttributeElement elem, int offset, float3 *dx, float3 *dy)
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{
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if(elem == ATTR_ELEMENT_CURVE) {
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/* idea: we can't derive any useful differentials here, but for tiled
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* mipmap image caching it would be useful to avoid reading the highest
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* detail level always. maybe a derivative based on the hair density
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* could be computed somehow? */
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#ifdef __RAY_DIFFERENTIALS__
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if(dx) *dx = make_float3(0.0f, 0.0f, 0.0f);
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if(dy) *dy = make_float3(0.0f, 0.0f, 0.0f);
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#endif
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return float4_to_float3(kernel_tex_fetch(__attributes_float3, offset + sd->prim));
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}
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else if(elem == ATTR_ELEMENT_CURVE_KEY) {
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float4 curvedata = kernel_tex_fetch(__curves, sd->prim);
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int k0 = __float_as_int(curvedata.x) + sd->segment;
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int k1 = k0 + 1;
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float3 f0 = float4_to_float3(kernel_tex_fetch(__attributes_float3, offset + k0));
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float3 f1 = float4_to_float3(kernel_tex_fetch(__attributes_float3, offset + k1));
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#ifdef __RAY_DIFFERENTIALS__
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if(dx) *dx = sd->du.dx*(f1 - f0);
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if(dy) *dy = make_float3(0.0f, 0.0f, 0.0f);
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#endif
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return (1.0f - sd->u)*f0 + sd->u*f1;
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}
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else {
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#ifdef __RAY_DIFFERENTIALS__
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if(dx) *dx = make_float3(0.0f, 0.0f, 0.0f);
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if(dy) *dy = make_float3(0.0f, 0.0f, 0.0f);
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#endif
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return make_float3(0.0f, 0.0f, 0.0f);
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}
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}
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/* hair info node functions */
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__device float curve_thickness(KernelGlobals *kg, ShaderData *sd)
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{
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float r = 0.0f;
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if(sd->segment != (int)~0) {
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float4 curvedata = kernel_tex_fetch(__curves, sd->prim);
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int k0 = __float_as_int(curvedata.x) + sd->segment;
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int k1 = k0 + 1;
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float4 P1 = kernel_tex_fetch(__curve_keys, k0);
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float4 P2 = kernel_tex_fetch(__curve_keys, k1);
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r = (P2.w - P1.w) * sd->u + P1.w;
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}
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return r*2.0f;
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}
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__device float3 curve_tangent_normal(KernelGlobals *kg, ShaderData *sd)
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{
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float3 tgN = make_float3(0.0f,0.0f,0.0f);
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if(sd->segment != (int)~0) {
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float normalmix = kernel_data.curve_kernel_data.normalmix;
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tgN = -(-sd->I - sd->dPdu * (dot(sd->dPdu,-sd->I) * normalmix / len_squared(sd->dPdu)));
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tgN = normalize(tgN);
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/* need to find suitable scaled gd for corrected normal */
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#if 0
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if (kernel_data.curve_kernel_data.use_tangent_normal_correction)
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tgN = normalize(tgN - gd * sd->dPdu);
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#endif
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}
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return tgN;
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}
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#endif
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CCL_NAMESPACE_END
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