/*
 * Copyright (C) 2016 Rob Clark <robclark@freedesktop.org>
 * Copyright © 2018 Google, Inc.
 *
 * 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, sublicense,
 * 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 NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS 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.
 *
 * Authors:
 *    Rob Clark <robclark@freedesktop.org>
 */

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

#include "fd6_blend.h"
#include "fd6_context.h"
#include "fd6_format.h"
#include "fd6_pack.h"

// XXX move somewhere common.. same across a3xx/a4xx/a5xx..
static enum a3xx_rb_blend_opcode
blend_func(unsigned func)
{
	switch (func) {
	case PIPE_BLEND_ADD:
		return BLEND_DST_PLUS_SRC;
	case PIPE_BLEND_MIN:
		return BLEND_MIN_DST_SRC;
	case PIPE_BLEND_MAX:
		return BLEND_MAX_DST_SRC;
	case PIPE_BLEND_SUBTRACT:
		return BLEND_SRC_MINUS_DST;
	case PIPE_BLEND_REVERSE_SUBTRACT:
		return BLEND_DST_MINUS_SRC;
	default:
		DBG("invalid blend func: %x", func);
		return 0;
	}
}

struct fd6_blend_variant *
__fd6_setup_blend_variant(struct fd6_blend_stateobj *blend, unsigned sample_mask)
{
	const struct pipe_blend_state *cso = &blend->base;
	struct fd6_blend_variant *so;
	enum a3xx_rop_code rop = ROP_COPY;
	bool reads_dest = false;
	unsigned mrt_blend = 0;

	if (cso->logicop_enable) {
		rop = cso->logicop_func;  /* maps 1:1 */
		reads_dest = util_logicop_reads_dest(cso->logicop_func);
	}

	so = rzalloc_size(blend, sizeof(*so));
	if (!so)
		return NULL;

	struct fd_ringbuffer *ring = fd_ringbuffer_new_object(blend->ctx->pipe,
			((A6XX_MAX_RENDER_TARGETS * 4) + 6) * 4);
	so->stateobj = ring;

	for (unsigned i = 0; i <= cso->max_rt; i++) {
		const struct pipe_rt_blend_state *rt;

		if (cso->independent_blend_enable)
			rt = &cso->rt[i];
		else
			rt = &cso->rt[0];

		OUT_REG(ring, A6XX_RB_MRT_BLEND_CONTROL(i,
				.rgb_src_factor     = fd_blend_factor(rt->rgb_src_factor),
				.rgb_blend_opcode   = blend_func(rt->rgb_func),
				.rgb_dest_factor    = fd_blend_factor(rt->rgb_dst_factor),
				.alpha_src_factor   = fd_blend_factor(rt->alpha_src_factor),
				.alpha_blend_opcode = blend_func(rt->alpha_func),
				.alpha_dest_factor  = fd_blend_factor(rt->alpha_dst_factor),
			));

		OUT_REG(ring, A6XX_RB_MRT_CONTROL(i,
				.rop_code         = rop,
				.rop_enable       = cso->logicop_enable,
				.component_enable = rt->colormask,
				.blend            = rt->blend_enable,
				.blend2           = rt->blend_enable,
			));

		if (rt->blend_enable) {
			mrt_blend |= (1 << i);
		}

		if (reads_dest) {
			mrt_blend |= (1 << i);
		}
	}

	OUT_REG(ring, A6XX_RB_DITHER_CNTL(
			.dither_mode_mrt0 = cso->dither ? DITHER_ALWAYS : DITHER_DISABLE,
			.dither_mode_mrt1 = cso->dither ? DITHER_ALWAYS : DITHER_DISABLE,
			.dither_mode_mrt2 = cso->dither ? DITHER_ALWAYS : DITHER_DISABLE,
			.dither_mode_mrt3 = cso->dither ? DITHER_ALWAYS : DITHER_DISABLE,
			.dither_mode_mrt4 = cso->dither ? DITHER_ALWAYS : DITHER_DISABLE,
			.dither_mode_mrt5 = cso->dither ? DITHER_ALWAYS : DITHER_DISABLE,
			.dither_mode_mrt6 = cso->dither ? DITHER_ALWAYS : DITHER_DISABLE,
			.dither_mode_mrt7 = cso->dither ? DITHER_ALWAYS : DITHER_DISABLE,
		));

	OUT_REG(ring, A6XX_SP_BLEND_CNTL(
			.unk8              = true,
			.alpha_to_coverage = cso->alpha_to_coverage,
			.enabled           = !!mrt_blend,
		));

	OUT_REG(ring, A6XX_RB_BLEND_CNTL(
			.enable_blend      = mrt_blend,
			.alpha_to_coverage = cso->alpha_to_coverage,
			.alpha_to_one = cso->alpha_to_one,
			.independent_blend = cso->independent_blend_enable,
			.sample_mask       = sample_mask
		));

	so->sample_mask = sample_mask;

	util_dynarray_append(&blend->variants, struct fd6_blend_variant *, so);

	return so;
}

void *
fd6_blend_state_create(struct pipe_context *pctx,
		const struct pipe_blend_state *cso)
{
	struct fd6_blend_stateobj *so;

	so = rzalloc_size(NULL, sizeof(*so));
	if (!so)
		return NULL;

	so->base = *cso;
	so->ctx = fd_context(pctx);

	if (cso->logicop_enable) {
		so->reads_dest |= util_logicop_reads_dest(cso->logicop_func);
	}

	unsigned nr = cso->independent_blend_enable ? cso->max_rt : 0;
	for (unsigned i = 0; i <= nr; i++) {
		const struct pipe_rt_blend_state *rt = &cso->rt[i];

		so->reads_dest |= rt->blend_enable;

		/* From the PoV of LRZ, having masked color channels is
		 * the same as having blend enabled, in that the draw will
		 * care about the fragments from an earlier draw.
		 *
		 * NOTE we actually don't care about masked color channels
		 * that don't actually exist in the render target, but we
		 * don't know the render target format here to determine
		 * that.  It is probably not worth worrying about, but if
		 * we find a game/benchmark that goes out of it's way to
		 * mask off non-existent channels, we should fixup the
		 * pipe_blend_state to give us more info.
		 */
		if (rt->blend_enable || (rt->colormask != 0xf)) {
			so->reads_dest = true;
		}
	}

	util_dynarray_init(&so->variants, so);

	return so;
}

void
fd6_blend_state_delete(struct pipe_context *pctx, void *hwcso)
{
	struct fd6_blend_stateobj *so = hwcso;

	util_dynarray_foreach(&so->variants, struct fd6_blend_variant *, vp) {
		struct fd6_blend_variant *v = *vp;
		fd_ringbuffer_del(v->stateobj);
	}

	ralloc_free(so);
}
