/*
 * Copyright © 2012-2013 Rob Clark <robclark@freedesktop.org>
 * SPDX-License-Identifier: MIT
 *
 * Authors:
 *    Rob Clark <robclark@freedesktop.org>
 */

#include "pipe/p_state.h"
#include "util/u_blend.h"
#include "util/u_memory.h"
#include "util/u_string.h"

#include "fd2_blend.h"
#include "fd2_context.h"
#include "fd2_util.h"

static enum a2xx_rb_blend_opcode
blend_func(unsigned func)
{
   switch (func) {
   case PIPE_BLEND_ADD:
      return BLEND2_DST_PLUS_SRC;
   case PIPE_BLEND_MIN:
      return BLEND2_MIN_DST_SRC;
   case PIPE_BLEND_MAX:
      return BLEND2_MAX_DST_SRC;
   case PIPE_BLEND_SUBTRACT:
      return BLEND2_SRC_MINUS_DST;
   case PIPE_BLEND_REVERSE_SUBTRACT:
      return BLEND2_DST_MINUS_SRC;
   default:
      DBG("invalid blend func: %x", func);
      return 0;
   }
}

void *
fd2_blend_state_create(struct pipe_context *pctx,
                       const struct pipe_blend_state *cso)
{
   const struct pipe_rt_blend_state *rt = &cso->rt[0];
   struct fd2_blend_stateobj *so;
   unsigned rop = PIPE_LOGICOP_COPY;

   if (cso->logicop_enable)
      rop = cso->logicop_func; /* 1:1 mapping with hw */

   if (cso->independent_blend_enable) {
      DBG("Unsupported! independent blend state");
      return NULL;
   }

   so = CALLOC_STRUCT(fd2_blend_stateobj);
   if (!so)
      return NULL;

   so->base = *cso;

   so->rb_colorcontrol = A2XX_RB_COLORCONTROL_ROP_CODE(rop);

   so->rb_blendcontrol =
      A2XX_RB_BLEND_CONTROL_COLOR_SRCBLEND(
         fd_blend_factor(rt->rgb_src_factor)) |
      A2XX_RB_BLEND_CONTROL_COLOR_COMB_FCN(blend_func(rt->rgb_func)) |
      A2XX_RB_BLEND_CONTROL_COLOR_DESTBLEND(
         fd_blend_factor(rt->rgb_dst_factor));

   /* hardware doesn't support SRC_ALPHA_SATURATE for alpha, but it is
    * equivalent to ONE */
   unsigned alpha_src_factor = rt->alpha_src_factor;
   if (alpha_src_factor == PIPE_BLENDFACTOR_SRC_ALPHA_SATURATE)
      alpha_src_factor = PIPE_BLENDFACTOR_ONE;

   so->rb_blendcontrol |=
      A2XX_RB_BLEND_CONTROL_ALPHA_SRCBLEND(fd_blend_factor(alpha_src_factor)) |
      A2XX_RB_BLEND_CONTROL_ALPHA_COMB_FCN(blend_func(rt->alpha_func)) |
      A2XX_RB_BLEND_CONTROL_ALPHA_DESTBLEND(
         fd_blend_factor(rt->alpha_dst_factor));

   if (rt->colormask & PIPE_MASK_R)
      so->rb_colormask |= A2XX_RB_COLOR_MASK_WRITE_RED;
   if (rt->colormask & PIPE_MASK_G)
      so->rb_colormask |= A2XX_RB_COLOR_MASK_WRITE_GREEN;
   if (rt->colormask & PIPE_MASK_B)
      so->rb_colormask |= A2XX_RB_COLOR_MASK_WRITE_BLUE;
   if (rt->colormask & PIPE_MASK_A)
      so->rb_colormask |= A2XX_RB_COLOR_MASK_WRITE_ALPHA;

   if (!rt->blend_enable)
      so->rb_colorcontrol |= A2XX_RB_COLORCONTROL_BLEND_DISABLE;

   if (cso->dither)
      so->rb_colorcontrol |= A2XX_RB_COLORCONTROL_DITHER_MODE(DITHER_ALWAYS);

   return so;
}