src/gallium/auxiliary/tgsi/tgsi_lowering.h

/*
 * Copyright (C) 2014 Rob Clark <robclark@freedesktop.org>
 *
 * 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>
 */

#ifndef TGSI_LOWERING_H_
#define TGSI_LOWERING_H_

#include "pipe/p_shader_tokens.h"
#include "tgsi/tgsi_scan.h"

struct tgsi_lowering_config
{
   /* For fragment shaders, generate a shader that emulates two
    * sided color by inserting a BGCOLOR input for each COLOR
    * input, and insert a CMP instruction to select the correct
    * color to use based on the TGSI_SEMANTIC_FACE input.
    *
    * Note that drivers which use this to emulate two sided color
    * will:
    *  a) need to generate (on demand) alternate shaders to use
    *     depending on the rasterizer state (ie. whether two
    *     sided shading enabled)
    *  b) expect to see the BGCOLOR semantic name in fragment
    *     shaders.  During linkage, the driver should simply
    *     map VS.OUT.BGCOLOR[n] to FS.IN.BGCOLOR[n] (in the
    *     same was as linking other outs/ins).
    */
   unsigned color_two_side:1;

   /* TODO support for alpha_to_one as well?? */

   /* Individual OPC lowerings, if lower_<opc> is TRUE then
    * enable lowering of TGSI_OPCODE_<opc>
    */
   unsigned lower_DST:1;
   unsigned lower_LRP:1;
   unsigned lower_FRC:1;
   unsigned lower_POW:1;
   unsigned lower_LIT:1;
   unsigned lower_EXP:1;
   unsigned lower_LOG:1;
   unsigned lower_DP4:1;
   unsigned lower_DP3:1;
   unsigned lower_DP2:1;
   unsigned lower_FLR:1;
   unsigned lower_CEIL:1;
   unsigned lower_TRUNC:1;

   /* bitmask of (1 << TGSI_TEXTURE_type): */
   unsigned lower_TXP;

   /* To emulate certain texture wrap modes, this can be used
    * to saturate the specified tex coord to [0.0, 1.0].  The
    * bits are according to sampler #, ie. if, for example:
    *
    *   (conf->saturate_s & (1 << n))
    *
    * is true, then the s coord for sampler n is saturated.
    */
   unsigned saturate_s, saturate_t, saturate_r;
};

const struct tgsi_token *
tgsi_transform_lowering(const struct tgsi_lowering_config *config,
                        const struct tgsi_token *tokens,
                        struct tgsi_shader_info *info);

#endif /* FREEDRENO_LOWERING_H_ */