/*
 * Copyright © 2014 Rob Clark <robclark@freedesktop.org>
 * SPDX-License-Identifier: MIT
 *
 * Authors:
 *    Rob Clark <robclark@freedesktop.org>
 */

#include "tgsi/tgsi_text.h"
#include "tgsi/tgsi_ureg.h"

#include "util/u_simple_shaders.h"

#include "freedreno_context.h"
#include "freedreno_program.h"

static void
update_bound_stage(struct fd_context *ctx, enum pipe_shader_type shader,
                   bool bound) assert_dt
{
   uint32_t bound_shader_stages = ctx->bound_shader_stages;
   if (bound) {
      ctx->bound_shader_stages |= BIT(shader);
   } else {
      ctx->bound_shader_stages &= ~BIT(shader);
   }
   if (ctx->update_draw && (bound_shader_stages != ctx->bound_shader_stages))
      ctx->update_draw(ctx);
}

static void
fd_set_tess_state(struct pipe_context *pctx,
                  const float default_outer_level[4],
                  const float default_inner_level[2])
   in_dt
{
   struct fd_context *ctx = fd_context(pctx);

   /* These turn into driver-params where are emitted on every draw if
    * needed by the shader (they will only be needed by pass-through
    * TCS shader)
    */
   memcpy(ctx->default_outer_level,
          default_outer_level,
          sizeof(ctx->default_outer_level));

   memcpy(ctx->default_inner_level,
          default_inner_level,
          sizeof(ctx->default_inner_level));
}

static void
fd_set_patch_vertices(struct pipe_context *pctx, uint8_t patch_vertices) in_dt
{
   struct fd_context *ctx = fd_context(pctx);

   if (ctx->patch_vertices == patch_vertices)
      return;

   ctx->patch_vertices = patch_vertices;

   /* If we have tessellation this dirties the TCS state.  Check for TES
    * stage as TCS could be NULL (passthrough)
    */
   if (ctx->prog.ds || ctx->prog.hs) {
      fd_context_dirty_shader(ctx, PIPE_SHADER_TESS_CTRL, FD_DIRTY_SHADER_PROG);
   }
}

static void
fd_vs_state_bind(struct pipe_context *pctx, void *hwcso) in_dt
{
   struct fd_context *ctx = fd_context(pctx);
   ctx->prog.vs = hwcso;
   fd_context_dirty_shader(ctx, PIPE_SHADER_VERTEX, FD_DIRTY_SHADER_PROG);
   update_bound_stage(ctx, PIPE_SHADER_VERTEX, !!hwcso);
}

static void
fd_tcs_state_bind(struct pipe_context *pctx, void *hwcso) in_dt
{
   struct fd_context *ctx = fd_context(pctx);
   ctx->prog.hs = hwcso;
   fd_context_dirty_shader(ctx, PIPE_SHADER_TESS_CTRL, FD_DIRTY_SHADER_PROG);
   update_bound_stage(ctx, PIPE_SHADER_TESS_CTRL, !!hwcso);
}

static void
fd_tes_state_bind(struct pipe_context *pctx, void *hwcso) in_dt
{
   struct fd_context *ctx = fd_context(pctx);
   ctx->prog.ds = hwcso;
   fd_context_dirty_shader(ctx, PIPE_SHADER_TESS_EVAL, FD_DIRTY_SHADER_PROG);
   update_bound_stage(ctx, PIPE_SHADER_TESS_EVAL, !!hwcso);
}

static void
fd_gs_state_bind(struct pipe_context *pctx, void *hwcso) in_dt
{
   struct fd_context *ctx = fd_context(pctx);
   ctx->prog.gs = hwcso;
   fd_context_dirty_shader(ctx, PIPE_SHADER_GEOMETRY, FD_DIRTY_SHADER_PROG);
   update_bound_stage(ctx, PIPE_SHADER_GEOMETRY, !!hwcso);
}

static void
fd_fs_state_bind(struct pipe_context *pctx, void *hwcso) in_dt
{
   struct fd_context *ctx = fd_context(pctx);
   ctx->prog.fs = hwcso;
   fd_context_dirty_shader(ctx, PIPE_SHADER_FRAGMENT, FD_DIRTY_SHADER_PROG);
   update_bound_stage(ctx, PIPE_SHADER_FRAGMENT, !!hwcso);
}

static const char *solid_fs = "FRAG                                        \n"
                              "PROPERTY FS_COLOR0_WRITES_ALL_CBUFS 1       \n"
                              "DCL CONST[0]                                \n"
                              "DCL OUT[0], COLOR                           \n"
                              "  0: MOV OUT[0], CONST[0]                   \n"
                              "  1: END                                    \n";

static const char *solid_vs = "VERT                                        \n"
                              "DCL IN[0]                                   \n"
                              "DCL OUT[0], POSITION                        \n"
                              "  0: MOV OUT[0], IN[0]                      \n"
                              "  1: END                                    \n";

static void *
assemble_tgsi(struct pipe_context *pctx, const char *src, bool frag)
{
   struct tgsi_token toks[32];
   struct pipe_shader_state cso = {
      .tokens = toks,
   };

   bool ret = tgsi_text_translate(src, toks, ARRAY_SIZE(toks));
   assume(ret);

   if (frag)
      return pctx->create_fs_state(pctx, &cso);
   else
      return pctx->create_vs_state(pctx, &cso);
}

/* the correct semantic to use for the texcoord varying depends on pipe-cap: */
static enum tgsi_semantic
texcoord_semantic(struct pipe_context *pctx)
{
   struct pipe_screen *pscreen = pctx->screen;

   if (pscreen->get_param(pscreen, PIPE_CAP_TGSI_TEXCOORD)) {
      return TGSI_SEMANTIC_TEXCOORD;
   } else {
      return TGSI_SEMANTIC_GENERIC;
   }
}

static void *
fd_prog_blit_vs(struct pipe_context *pctx)
{
   struct ureg_program *ureg;

   ureg = ureg_create(PIPE_SHADER_VERTEX);
   if (!ureg)
      return NULL;

   struct ureg_src in0 = ureg_DECL_vs_input(ureg, 0);
   struct ureg_src in1 = ureg_DECL_vs_input(ureg, 1);

   struct ureg_dst out0 = ureg_DECL_output(ureg, texcoord_semantic(pctx), 0);
   struct ureg_dst out1 = ureg_DECL_output(ureg, TGSI_SEMANTIC_POSITION, 1);

   ureg_MOV(ureg, out0, in0);
   ureg_MOV(ureg, out1, in1);

   ureg_END(ureg);

   return ureg_create_shader_and_destroy(ureg, pctx);
}

static void *
fd_prog_blit_fs(struct pipe_context *pctx, int rts, bool depth)
{
   int i;
   struct ureg_src tc;
   struct ureg_program *ureg;

   assert(rts <= MAX_RENDER_TARGETS);

   ureg = ureg_create(PIPE_SHADER_FRAGMENT);
   if (!ureg)
      return NULL;

   tc = ureg_DECL_fs_input(ureg, texcoord_semantic(pctx), 0,
                           TGSI_INTERPOLATE_PERSPECTIVE);
   for (i = 0; i < rts; i++)
      ureg_TEX(ureg, ureg_DECL_output(ureg, TGSI_SEMANTIC_COLOR, i),
               TGSI_TEXTURE_2D, tc, ureg_DECL_sampler(ureg, i));
   if (depth)
      ureg_TEX(ureg,
               ureg_writemask(ureg_DECL_output(ureg, TGSI_SEMANTIC_POSITION, 0),
                              TGSI_WRITEMASK_Z),
               TGSI_TEXTURE_2D, tc, ureg_DECL_sampler(ureg, rts));

   ureg_END(ureg);

   return ureg_create_shader_and_destroy(ureg, pctx);
}

void
fd_prog_init(struct pipe_context *pctx)
{
   struct fd_context *ctx = fd_context(pctx);
   int i;

   pctx->bind_vs_state = fd_vs_state_bind;
   pctx->bind_tcs_state = fd_tcs_state_bind;
   pctx->bind_tes_state = fd_tes_state_bind;
   pctx->bind_gs_state = fd_gs_state_bind;
   pctx->bind_fs_state = fd_fs_state_bind;
   pctx->set_tess_state = fd_set_tess_state;
   pctx->set_patch_vertices = fd_set_patch_vertices;

   if (ctx->flags & PIPE_CONTEXT_COMPUTE_ONLY)
      return;

   ctx->solid_prog.fs = assemble_tgsi(pctx, solid_fs, true);
   ctx->solid_prog.vs = assemble_tgsi(pctx, solid_vs, false);

   if (ctx->screen->gen >= 6) {
      ctx->solid_layered_prog.fs = assemble_tgsi(pctx, solid_fs, true);
      ctx->solid_layered_prog.vs = util_make_layered_clear_vertex_shader(pctx);
   }

   if (ctx->screen->gen >= 5)
      return;

   ctx->blit_prog[0].vs = fd_prog_blit_vs(pctx);
   ctx->blit_prog[0].fs = fd_prog_blit_fs(pctx, 1, false);

   if (ctx->screen->gen < 3)
      return;

   for (i = 1; i < ctx->screen->max_rts; i++) {
      ctx->blit_prog[i].vs = ctx->blit_prog[0].vs;
      ctx->blit_prog[i].fs = fd_prog_blit_fs(pctx, i + 1, false);
   }

   ctx->blit_z.vs = ctx->blit_prog[0].vs;
   ctx->blit_z.fs = fd_prog_blit_fs(pctx, 0, true);
   ctx->blit_zs.vs = ctx->blit_prog[0].vs;
   ctx->blit_zs.fs = fd_prog_blit_fs(pctx, 1, true);
}

void
fd_prog_fini(struct pipe_context *pctx)
{
   struct fd_context *ctx = fd_context(pctx);
   int i;

   if (ctx->flags & PIPE_CONTEXT_COMPUTE_ONLY)
      return;

   pctx->delete_vs_state(pctx, ctx->solid_prog.vs);
   pctx->delete_fs_state(pctx, ctx->solid_prog.fs);

   if (ctx->screen->gen >= 6) {
      pctx->delete_vs_state(pctx, ctx->solid_layered_prog.vs);
      pctx->delete_fs_state(pctx, ctx->solid_layered_prog.fs);
   }

   if (ctx->screen->gen >= 5)
      return;

   pctx->delete_vs_state(pctx, ctx->blit_prog[0].vs);
   pctx->delete_fs_state(pctx, ctx->blit_prog[0].fs);

   if (ctx->screen->gen < 3)
      return;

   for (i = 1; i < ctx->screen->max_rts; i++)
      pctx->delete_fs_state(pctx, ctx->blit_prog[i].fs);
   pctx->delete_fs_state(pctx, ctx->blit_z.fs);
   pctx->delete_fs_state(pctx, ctx->blit_zs.fs);
}