diff options
Diffstat (limited to 'intern/gawain/src/gwn_attr_binding.c')
-rw-r--r-- | intern/gawain/src/gwn_attr_binding.c | 70 |
1 files changed, 70 insertions, 0 deletions
diff --git a/intern/gawain/src/gwn_attr_binding.c b/intern/gawain/src/gwn_attr_binding.c new file mode 100644 index 00000000000..7647a927b1e --- /dev/null +++ b/intern/gawain/src/gwn_attr_binding.c @@ -0,0 +1,70 @@ + +// Gawain vertex attribute binding +// +// This code is part of the Gawain library, with modifications +// specific to integration with Blender. +// +// Copyright 2016 Mike Erwin +// +// This Source Code Form is subject to the terms of the Mozilla Public License, v. 2.0. If a copy of +// the MPL was not distributed with this file, You can obtain one at https://mozilla.org/MPL/2.0/. + +#include "gwn_attr_binding.h" +#include "gwn_attr_binding_private.h" +#include <stddef.h> + +#if GWN_VERT_ATTR_MAX_LEN != 16 + #error "attrib binding code assumes GWN_VERT_ATTR_MAX_LEN = 16" +#endif + +void AttribBinding_clear(Gwn_AttrBinding* binding) + { + binding->loc_bits = 0; + binding->enabled_bits = 0; + } + +unsigned read_attrib_location(const Gwn_AttrBinding* binding, unsigned a_idx) + { +#if TRUST_NO_ONE + assert(a_idx < GWN_VERT_ATTR_MAX_LEN); + assert(binding->enabled_bits & (1 << a_idx)); +#endif + + return (binding->loc_bits >> (4 * a_idx)) & 0xF; + } + +static void write_attrib_location(Gwn_AttrBinding* binding, unsigned a_idx, unsigned location) + { +#if TRUST_NO_ONE + assert(a_idx < GWN_VERT_ATTR_MAX_LEN); + assert(location < GWN_VERT_ATTR_MAX_LEN); +#endif + + const unsigned shift = 4 * a_idx; + const uint64_t mask = ((uint64_t)0xF) << shift; + // overwrite this attrib's previous location + binding->loc_bits = (binding->loc_bits & ~mask) | (location << shift); + // mark this attrib as enabled + binding->enabled_bits |= 1 << a_idx; + } + +void get_attrib_locations(const Gwn_VertFormat* format, Gwn_AttrBinding* binding, const Gwn_ShaderInterface* shaderface) + { + AttribBinding_clear(binding); + + for (unsigned a_idx = 0; a_idx < format->attrib_ct; ++a_idx) + { + const Gwn_VertAttr* a = format->attribs + a_idx; + for (unsigned n_idx = 0; n_idx < a->name_ct; ++n_idx) + { + const Gwn_ShaderInput* input = GWN_shaderinterface_attr(shaderface, a->name[n_idx]); + +#if TRUST_NO_ONE + assert(input != NULL); + // TODO: make this a recoverable runtime error? indicates mismatch between vertex format and program +#endif + + write_attrib_location(binding, a_idx, input->location); + } + } + } |