Subversion Repositories Kolibri OS

/**************************************************************************

 *

 * Copyright 2009 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 above copyright notice and this permission notice (including the

 * next paragraph) shall be included in all copies or substantial portions

 * of the Software.

 *

 * 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 VMWARE 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.

 *

 **************************************************************************/

/**

 * Alpha testing to LLVM IR translation.

 *

 * @author Jose Fonseca 

 */

#include "pipe/p_state.h"

#include "util/u_format.h"

#include "gallivm/lp_bld_type.h"

#include "gallivm/lp_bld_const.h"

#include "gallivm/lp_bld_arit.h"

#include "gallivm/lp_bld_conv.h"

#include "gallivm/lp_bld_logic.h"

#include "gallivm/lp_bld_flow.h"

#include "gallivm/lp_bld_debug.h"

#include "lp_bld_alpha.h"

void

lp_build_alpha_test(struct gallivm_state *gallivm,

                    unsigned func,

                    struct lp_type type,

                    const struct util_format_description *cbuf_format_desc,

                    struct lp_build_mask_context *mask,

                    LLVMValueRef alpha,

                    LLVMValueRef ref,

                    boolean do_branch)

{

   struct lp_build_context bld;

   LLVMValueRef test;

   lp_build_context_init(&bld, gallivm, type);

   /*

    * Alpha testing needs to be done in the color buffer precision.

    *

    * TODO: Ideally, instead of duplicating the color conversion code, we would do

    * alpha testing after converting the output colors, but that's not very

    * convenient, because it needs to be done before depth testing.  Hopefully

    * LLVM will detect and remove the duplicate expression.

    *

    * FIXME: This should be generalized to formats other than rgba8 variants.

    */

   if (type.floating &&

       util_format_is_rgba8_variant(cbuf_format_desc)) {

      const unsigned dst_width = 8;

      alpha = lp_build_clamp(&bld, alpha, bld.zero, bld.one);

      ref   = lp_build_clamp(&bld, ref,   bld.zero, bld.one);

      alpha = lp_build_clamped_float_to_unsigned_norm(gallivm, type, dst_width, alpha);

      ref   = lp_build_clamped_float_to_unsigned_norm(gallivm, type, dst_width, ref);

      type.floating = 0;

      lp_build_context_init(&bld, gallivm, type);

   }

   test = lp_build_cmp(&bld, func, alpha, ref);

   lp_build_name(test, "alpha_mask");

   lp_build_mask_update(mask, test);

   if (do_branch)

      lp_build_mask_check(mask);

}