gallivm: Factor out the quad derivative code into a single place. Fix ddy.

For ddy it should be (bottom - top).

1 files changed, 96 insertions, 0 deletions

diff --git a/src/gallium/auxiliary/gallivm/lp_bld_quad.h b/src/gallium/auxiliary/gallivm/lp_bld_quad.h
new file mode 100644
index 00000000000..b7992912927
--- /dev/null
+++ b/src/gallium/auxiliary/gallivm/lp_bld_quad.h
@@ -0,0 +1,96 @@
+/**************************************************************************
+ *
+ * Copyright 2010 VMware, Inc.
+ * All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sub license, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
+ * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+ * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
+ * USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * The above copyright notice and this permission notice (including the
+ * next paragraph) shall be included in all copies or substantial portions
+ * of the Software.
+ *
+ **************************************************************************/
+
+
+#ifndef LP_BLD_QUAD_H_
+#define LP_BLD_QUAD_H_
+
+
+#include "gallivm/lp_bld.h"
+
+
+struct lp_build_context;
+
+
+/*
+ * Each quad is composed of four elements.
+ *
+ * #########
+ * # 0 | 1 #
+ * #---+---#
+ * # 2 | 3 #
+ * #########
+ */
+
+enum lp_bld_quad {
+   LP_BLD_QUAD_TOP_LEFT     = 0,
+   LP_BLD_QUAD_TOP_RIGHT    = 1,
+   LP_BLD_QUAD_BOTTOM_LEFT  = 2,
+   LP_BLD_QUAD_BOTTOM_RIGHT = 3
+};
+
+
+/*
+ * (Vector) derivates.
+ *
+ * More than one quad is supported. The only requirement is that the vector
+ * contains a whole number of quads:
+ *
+ * ######### ######### ...
+ * # 0 | 1 # # 4 | 5 #
+ * #---+---# #---+---# ...
+ * # 2 | 3 # # 6 | 7 #
+ * ######### ######### ...
+ */
+
+LLVMValueRef
+lp_build_ddx(struct lp_build_context *bld,
+             LLVMValueRef a);
+
+
+LLVMValueRef
+lp_build_ddy(struct lp_build_context *bld,
+             LLVMValueRef a);
+
+
+/*
+ * Scalar derivatives.
+ *
+ * Same as getting the first value of above.
+ */
+
+LLVMValueRef
+lp_build_scalar_ddx(struct lp_build_context *bld,
+                    LLVMValueRef a);
+
+
+LLVMValueRef
+lp_build_scalar_ddy(struct lp_build_context *bld,
+                    LLVMValueRef a);
+
+
+#endif /* LP_BLD_QUAD_H_ */