mesa/src/util/blend.h

/*
 * Copyright 2023 Valve Corporation
 * Copyright 2007 VMware, Inc.
 * SPDX-License-Identifier: MIT
 */

#ifndef UTIL_BLEND_H
#define UTIL_BLEND_H

#include <stdbool.h>

#include "util/macros.h"

#define PIPE_BLENDFACTOR_INVERT_BIT (0x10)

enum pipe_blendfactor {
   PIPE_BLENDFACTOR_ONE = 1,
   PIPE_BLENDFACTOR_SRC_COLOR,
   PIPE_BLENDFACTOR_SRC_ALPHA,
   PIPE_BLENDFACTOR_DST_ALPHA,
   PIPE_BLENDFACTOR_DST_COLOR,
   PIPE_BLENDFACTOR_SRC_ALPHA_SATURATE,
   PIPE_BLENDFACTOR_CONST_COLOR,
   PIPE_BLENDFACTOR_CONST_ALPHA,
   PIPE_BLENDFACTOR_SRC1_COLOR,
   PIPE_BLENDFACTOR_SRC1_ALPHA,

   PIPE_BLENDFACTOR_ZERO = PIPE_BLENDFACTOR_INVERT_BIT | PIPE_BLENDFACTOR_ONE,
   PIPE_BLENDFACTOR_INV_SRC_COLOR,
   PIPE_BLENDFACTOR_INV_SRC_ALPHA,
   PIPE_BLENDFACTOR_INV_DST_ALPHA,
   PIPE_BLENDFACTOR_INV_DST_COLOR,

   /* Intentionally weird wrapping due to Gallium trace parsing this file */
   PIPE_BLENDFACTOR_INV_CONST_COLOR = PIPE_BLENDFACTOR_INVERT_BIT
                                    | PIPE_BLENDFACTOR_CONST_COLOR,
   PIPE_BLENDFACTOR_INV_CONST_ALPHA,
   PIPE_BLENDFACTOR_INV_SRC1_COLOR,
   PIPE_BLENDFACTOR_INV_SRC1_ALPHA,
};

static inline bool
util_blendfactor_is_inverted(enum pipe_blendfactor factor)
{
   /* By construction of the enum */
   return (factor & PIPE_BLENDFACTOR_INVERT_BIT);
}

static inline enum pipe_blendfactor
util_blendfactor_without_invert(enum pipe_blendfactor factor)
{
   /* By construction of the enum */
   return (enum pipe_blendfactor)(factor & ~PIPE_BLENDFACTOR_INVERT_BIT);
}

/**
 * Color blend factor enums are treated as their alpha counterpart when used
 * as the alpha blend factor.  This helper just converts from color to alpha.
 */
static inline enum pipe_blendfactor
util_blendfactor_to_alpha(enum pipe_blendfactor factor)
{
   switch (factor) {
#define UTIL_BLENDFACTOR_TO_ALPHA_CASE(x)       \
   case PIPE_BLENDFACTOR_##x##_COLOR:           \
      return PIPE_BLENDFACTOR_##x##_ALPHA;      \
   case PIPE_BLENDFACTOR_INV_##x##_COLOR:       \
      return PIPE_BLENDFACTOR_INV_##x##_ALPHA;

   UTIL_BLENDFACTOR_TO_ALPHA_CASE(SRC)
   UTIL_BLENDFACTOR_TO_ALPHA_CASE(DST)
   UTIL_BLENDFACTOR_TO_ALPHA_CASE(CONST)
   UTIL_BLENDFACTOR_TO_ALPHA_CASE(SRC1)

#undef UTIL_BLENDFACTOR_TO_ALPHA_CASE

   case PIPE_BLENDFACTOR_ONE:
   case PIPE_BLENDFACTOR_SRC_ALPHA:
   case PIPE_BLENDFACTOR_DST_ALPHA:
   case PIPE_BLENDFACTOR_SRC_ALPHA_SATURATE:
   case PIPE_BLENDFACTOR_CONST_ALPHA:
   case PIPE_BLENDFACTOR_SRC1_ALPHA:
   case PIPE_BLENDFACTOR_ZERO:
   case PIPE_BLENDFACTOR_INV_SRC_ALPHA:
   case PIPE_BLENDFACTOR_INV_DST_ALPHA:
   case PIPE_BLENDFACTOR_INV_CONST_ALPHA:
   case PIPE_BLENDFACTOR_INV_SRC1_ALPHA:
      return factor;
   }

   UNREACHABLE("Invalid blend factor");
}

enum pipe_blend_func {
   PIPE_BLEND_ADD,
   PIPE_BLEND_SUBTRACT,
   PIPE_BLEND_REVERSE_SUBTRACT,
   PIPE_BLEND_MIN,
   PIPE_BLEND_MAX,
};

enum pipe_logicop {
   PIPE_LOGICOP_CLEAR,
   PIPE_LOGICOP_NOR,
   PIPE_LOGICOP_AND_INVERTED,
   PIPE_LOGICOP_COPY_INVERTED,
   PIPE_LOGICOP_AND_REVERSE,
   PIPE_LOGICOP_INVERT,
   PIPE_LOGICOP_XOR,
   PIPE_LOGICOP_NAND,
   PIPE_LOGICOP_AND,
   PIPE_LOGICOP_EQUIV,
   PIPE_LOGICOP_NOOP,
   PIPE_LOGICOP_OR_INVERTED,
   PIPE_LOGICOP_COPY,
   PIPE_LOGICOP_OR_REVERSE,
   PIPE_LOGICOP_OR,
   PIPE_LOGICOP_SET,
};

enum pipe_advanced_blend_mode {
   PIPE_ADVANCED_BLEND_NONE = 0,
   PIPE_ADVANCED_BLEND_MULTIPLY,
   PIPE_ADVANCED_BLEND_SCREEN,
   PIPE_ADVANCED_BLEND_OVERLAY,
   PIPE_ADVANCED_BLEND_DARKEN,
   PIPE_ADVANCED_BLEND_LIGHTEN,
   PIPE_ADVANCED_BLEND_COLORDODGE,
   PIPE_ADVANCED_BLEND_COLORBURN,
   PIPE_ADVANCED_BLEND_HARDLIGHT,
   PIPE_ADVANCED_BLEND_SOFTLIGHT,
   PIPE_ADVANCED_BLEND_DIFFERENCE,
   PIPE_ADVANCED_BLEND_EXCLUSION,
   PIPE_ADVANCED_BLEND_HSL_HUE,
   PIPE_ADVANCED_BLEND_HSL_SATURATION,
   PIPE_ADVANCED_BLEND_HSL_COLOR,
   PIPE_ADVANCED_BLEND_HSL_LUMINOSITY,

   /* Extended blend modes */
   PIPE_ADVANCED_BLEND_SRC,
   PIPE_ADVANCED_BLEND_DST,
   PIPE_ADVANCED_BLEND_SRC_OVER,
   PIPE_ADVANCED_BLEND_DST_OVER,
   PIPE_ADVANCED_BLEND_SRC_IN,
   PIPE_ADVANCED_BLEND_DST_IN,
   PIPE_ADVANCED_BLEND_SRC_OUT,
   PIPE_ADVANCED_BLEND_DST_OUT,
   PIPE_ADVANCED_BLEND_SRC_ATOP,
   PIPE_ADVANCED_BLEND_DST_ATOP,
   PIPE_ADVANCED_BLEND_XOR,
   PIPE_ADVANCED_BLEND_INVERT,
   PIPE_ADVANCED_BLEND_INVERT_RGB,
   PIPE_ADVANCED_BLEND_LINEARDODGE,
   PIPE_ADVANCED_BLEND_LINEARBURN,
   PIPE_ADVANCED_BLEND_VIVIDLIGHT,
   PIPE_ADVANCED_BLEND_LINEARLIGHT,
   PIPE_ADVANCED_BLEND_PINLIGHT,
   PIPE_ADVANCED_BLEND_HARDMIX,
   PIPE_ADVANCED_BLEND_PLUS,
   PIPE_ADVANCED_BLEND_PLUS_CLAMPED,
   PIPE_ADVANCED_BLEND_PLUS_CLAMPED_ALPHA,
   PIPE_ADVANCED_BLEND_PLUS_DARKER,
   PIPE_ADVANCED_BLEND_MINUS,
   PIPE_ADVANCED_BLEND_MINUS_CLAMPED,
   PIPE_ADVANCED_BLEND_CONTRAST,
   PIPE_ADVANCED_BLEND_INVERT_OVG,
   PIPE_ADVANCED_BLEND_RED,
   PIPE_ADVANCED_BLEND_GREEN,
   PIPE_ADVANCED_BLEND_BLUE,
};

enum pipe_blend_overlap_mode {
   PIPE_BLEND_OVERLAP_UNCORRELATED = 0,
   PIPE_BLEND_OVERLAP_CONJOINT = 1,
   PIPE_BLEND_OVERLAP_DISJOINT = 2,
};

/**
 * When faking RGBX render target formats with RGBA ones, the blender is still
 * supposed to treat the destination's alpha channel as 1 instead of the
 * garbage that's there. Return a blend factor that will take that into
 * account.
 */
static inline enum pipe_blendfactor
util_blend_dst_alpha_to_one(enum pipe_blendfactor factor)
{
   switch (factor) {
   case PIPE_BLENDFACTOR_DST_ALPHA:
      return PIPE_BLENDFACTOR_ONE;
   case PIPE_BLENDFACTOR_INV_DST_ALPHA:
      return PIPE_BLENDFACTOR_ZERO;
   default:
      return factor;
   }
}

#endif