1 files changed, 85 insertions, 0 deletions
diff --git a/source/blender/gpu/intern/gpu_attr_binding.c b/source/blender/gpu/intern/gpu_attr_binding.c
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index 00000000000..398b97c7f9d
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+++ b/source/blender/gpu/intern/gpu_attr_binding.c
@@ -0,0 +1,85 @@
+/*
+ * ***** BEGIN GPL LICENSE BLOCK *****
+ *
+ * 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.
+ *
+ * The Original Code is Copyright (C) 2016 by Mike Erwin.
+ * All rights reserved.
+ *
+ * Contributor(s): Blender Foundation
+ *
+ * ***** END GPL LICENSE BLOCK *****
+ */
+
+/** \file blender/gpu/intern/gpu_attr_binding.c
+ *  \ingroup gpu
+ *
+ * GPU vertex attribute binding
+ */
+
+#include "GPU_attr_binding.h"
+#include "gpu_attr_binding_private.h"
+#include <stddef.h>
+#include <stdlib.h>
+
+#if GPU_VERT_ATTR_MAX_LEN != 16
+#  error "attrib binding code assumes GPU_VERT_ATTR_MAX_LEN = 16"
+#endif
+
+void AttribBinding_clear(GPUAttrBinding *binding)
+{
+	binding->loc_bits = 0;
+	binding->enabled_bits = 0;
+}
+
+uint read_attrib_location(const GPUAttrBinding *binding, uint a_idx)
+{
+#if TRUST_NO_ONE
+	assert(a_idx < GPU_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(GPUAttrBinding *binding, uint a_idx, uint location)
+{
+#if TRUST_NO_ONE
+	assert(a_idx < GPU_VERT_ATTR_MAX_LEN);
+	assert(location < GPU_VERT_ATTR_MAX_LEN);
+#endif
+	const uint 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 GPUVertFormat *format, GPUAttrBinding *binding, const GPUShaderInterface *shaderface)
+{
+	AttribBinding_clear(binding);
+
+	for (uint a_idx = 0; a_idx < format->attr_len; ++a_idx) {
+		const GPUVertAttr *a = format->attribs + a_idx;
+		for (uint n_idx = 0; n_idx < a->name_len; ++n_idx) {
+			const GPUShaderInput *input = GPU_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);
+		}
+	}
+}