/**************************************************************************
*
* Copyright 2012 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.
*
**************************************************************************/
#include "pipe/p_state.h"
#include "util/u_debug.h"
#include "gallivm/lp_bld_type.h"
#include "gallivm/lp_bld_arit.h"
#include "lp_bld_blend.h"
/**
* Is (a OP b) == (b OP a)?
*/
boolean
lp_build_blend_func_commutative(unsigned func)
{
switch (func) {
case PIPE_BLEND_ADD:
case PIPE_BLEND_MIN:
case PIPE_BLEND_MAX:
return TRUE;
case PIPE_BLEND_SUBTRACT:
case PIPE_BLEND_REVERSE_SUBTRACT:
return FALSE;
default:
assert(0);
return TRUE;
}
}
/**
* Whether the blending functions are the reverse of each other.
*/
boolean
lp_build_blend_func_reverse(unsigned rgb_func, unsigned alpha_func)
{
if(rgb_func == alpha_func)
return FALSE;
if(rgb_func == PIPE_BLEND_SUBTRACT && alpha_func == PIPE_BLEND_REVERSE_SUBTRACT)
return TRUE;
if(rgb_func == PIPE_BLEND_REVERSE_SUBTRACT && alpha_func == PIPE_BLEND_SUBTRACT)
return TRUE;
return FALSE;
}
/**
* Whether the blending factors are complementary of each other.
*/
static INLINE boolean
lp_build_blend_factor_complementary(unsigned src_factor, unsigned dst_factor)
{
return dst_factor == (src_factor ^ 0x10);
}
/**
* @sa http://www.opengl.org/sdk/docs/man/xhtml/glBlendEquationSeparate.xml
*/
LLVMValueRef
lp_build_blend_func(struct lp_build_context *bld,
unsigned func,
LLVMValueRef term1,
LLVMValueRef term2)
{
switch (func) {
case PIPE_BLEND_ADD:
return lp_build_add(bld, term1, term2);
case PIPE_BLEND_SUBTRACT:
return lp_build_sub(bld, term1, term2);
case PIPE_BLEND_REVERSE_SUBTRACT:
return lp_build_sub(bld, term2, term1);
case PIPE_BLEND_MIN:
return lp_build_min(bld, term1, term2);
case PIPE_BLEND_MAX:
return lp_build_max(bld, term1, term2);
default:
assert(0);
return bld->zero;
}
}
/**
* Performs optimisations and blending independent of SoA/AoS
*
* @param func the blend function
* @param factor_src PIPE_BLENDFACTOR_xxx
* @param factor_dst PIPE_BLENDFACTOR_xxx
* @param src source rgba
* @param dst dest rgba
* @param src_factor src factor computed value
* @param dst_factor dst factor computed value
* @param not_alpha_dependent same factors accross all channels of src/dst
*
* not_alpha_dependent should be:
* SoA: always true as it is only one channel at a time
* AoS: rgb_src_factor == alpha_src_factor && rgb_dst_factor == alpha_dst_factor
*
* Note that pretty much every possible optimisation can only be done on non-unorm targets
* due to unorm values not going above 1.0 meaning factorisation can change results.
* e.g. (0.9 * 0.9) + (0.9 * 0.9) != 0.9 * (0.9 + 0.9) as result of + is always <= 1.
*/
LLVMValueRef
lp_build_blend(struct lp_build_context *bld,
unsigned func,
unsigned factor_src,
unsigned factor_dst,
LLVMValueRef src,
LLVMValueRef dst,
LLVMValueRef src_factor,
LLVMValueRef dst_factor,
boolean not_alpha_dependent,
boolean optimise_only)
{
LLVMValueRef result, src_term, dst_term;
/* If we are not alpha dependent we can mess with the src/dst factors */
if (not_alpha_dependent) {
if (lp_build_blend_factor_complementary(factor_src, factor_dst)) {
if (func == PIPE_BLEND_ADD) {
if (factor_src < factor_dst) {
return lp_build_lerp(bld, src_factor, dst, src);
} else {
return lp_build_lerp(bld, dst_factor, src, dst);
}
} else if(bld->type.floating && func == PIPE_BLEND_SUBTRACT) {
result = lp_build_add(bld, src, dst);
if (factor_src < factor_dst) {
result = lp_build_mul(bld, result, src_factor);
return lp_build_sub(bld, result, dst);
} else {
result = lp_build_mul(bld, result, dst_factor);
return lp_build_sub(bld, src, result);
}
} else if(bld->type.floating && func == PIPE_BLEND_REVERSE_SUBTRACT) {
result = lp_build_add(bld, src, dst);
if (factor_src < factor_dst) {
result = lp_build_mul(bld, result, src_factor);
return lp_build_sub(bld, dst, result);
} else {
result = lp_build_mul(bld, result, dst_factor);
return lp_build_sub(bld, result, src);
}
}
}
if (bld->type.floating && factor_src == factor_dst) {
if (func == PIPE_BLEND_ADD ||
func == PIPE_BLEND_SUBTRACT ||
func == PIPE_BLEND_REVERSE_SUBTRACT) {
LLVMValueRef result;
result = lp_build_blend_func(bld, func, src, dst);
return lp_build_mul(bld, result, src_factor);
}
}
}
if (optimise_only)
return NULL;
src_term = lp_build_mul(bld, src, src_factor);
dst_term = lp_build_mul(bld, dst, dst_factor);
return lp_build_blend_func(bld, func, src_term, dst_term);
}