/**************************************************************************
 *
 * Copyright 2009 Younes Manton.
 * All Rights Reserved.
 *
 * 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, sub license, 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 NON-INFRINGEMENT.
 * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS 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.
 *
 **************************************************************************/

#include <assert.h>

#include "pipe/p_compiler.h"
#include "pipe/p_context.h"

#include "util/u_memory.h"
#include "util/u_draw.h"
#include "util/u_surface.h"
#include "util/u_upload_mgr.h"

#include "tgsi/tgsi_ureg.h"

#include "vl_csc.h"
#include "vl_types.h"

#include "vl_compositor_gfx.h"

enum VS_OUTPUT
{
   VS_O_VPOS = 0,
   VS_O_COLOR = 0,
   VS_O_VTEX = 0,
   VS_O_VTOP,
   VS_O_VBOTTOM,
};

void *
create_vert_shader(struct vl_compositor *c)
{
   struct ureg_program *shader;
   struct ureg_src vpos, vtex, color;
   struct ureg_dst tmp;
   struct ureg_dst o_vpos, o_vtex, o_color;
   struct ureg_dst o_vtop, o_vbottom;

   shader = ureg_create(PIPE_SHADER_VERTEX);
   if (!shader)
      return false;

   vpos = ureg_DECL_vs_input(shader, 0);
   vtex = ureg_DECL_vs_input(shader, 1);
   color = ureg_DECL_vs_input(shader, 2);
   tmp = ureg_DECL_temporary(shader);
   o_vpos = ureg_DECL_output(shader, TGSI_SEMANTIC_POSITION, VS_O_VPOS);
   o_color = ureg_DECL_output(shader, TGSI_SEMANTIC_COLOR, VS_O_COLOR);
   o_vtex = ureg_DECL_output(shader, TGSI_SEMANTIC_GENERIC, VS_O_VTEX);
   o_vtop = ureg_DECL_output(shader, TGSI_SEMANTIC_GENERIC, VS_O_VTOP);
   o_vbottom = ureg_DECL_output(shader, TGSI_SEMANTIC_GENERIC, VS_O_VBOTTOM);

   /*
    * o_vpos = vpos
    * o_vtex = vtex
    * o_color = color
    */
   ureg_MOV(shader, o_vpos, vpos);
   ureg_MOV(shader, o_vtex, vtex);
   ureg_MOV(shader, o_color, color);

   /*
    * tmp.x = vtex.w / 2
    * tmp.y = vtex.w / 4
    *
    * o_vtop.x = vtex.x
    * o_vtop.y = vtex.y * tmp.x + 0.25f
    * o_vtop.z = vtex.y * tmp.y + 0.25f
    * o_vtop.w = 1 / tmp.x
    *
    * o_vbottom.x = vtex.x
    * o_vbottom.y = vtex.y * tmp.x - 0.25f
    * o_vbottom.z = vtex.y * tmp.y - 0.25f
    * o_vbottom.w = 1 / tmp.y
    */
   ureg_MUL(shader, ureg_writemask(tmp, TGSI_WRITEMASK_X),
            ureg_scalar(vtex, TGSI_SWIZZLE_W), ureg_imm1f(shader, 0.5f));
   ureg_MUL(shader, ureg_writemask(tmp, TGSI_WRITEMASK_Y),
            ureg_scalar(vtex, TGSI_SWIZZLE_W), ureg_imm1f(shader, 0.25f));

   ureg_MOV(shader, ureg_writemask(o_vtop, TGSI_WRITEMASK_X), vtex);
   ureg_MAD(shader, ureg_writemask(o_vtop, TGSI_WRITEMASK_Y), ureg_scalar(vtex, TGSI_SWIZZLE_Y),
            ureg_scalar(ureg_src(tmp), TGSI_SWIZZLE_X), ureg_imm1f(shader, 0.25f));
   ureg_MAD(shader, ureg_writemask(o_vtop, TGSI_WRITEMASK_Z), ureg_scalar(vtex, TGSI_SWIZZLE_Y),
            ureg_scalar(ureg_src(tmp), TGSI_SWIZZLE_Y), ureg_imm1f(shader, 0.25f));
   ureg_RCP(shader, ureg_writemask(o_vtop, TGSI_WRITEMASK_W),
            ureg_scalar(ureg_src(tmp), TGSI_SWIZZLE_X));

   ureg_MOV(shader, ureg_writemask(o_vbottom, TGSI_WRITEMASK_X), vtex);
   ureg_MAD(shader, ureg_writemask(o_vbottom, TGSI_WRITEMASK_Y), ureg_scalar(vtex, TGSI_SWIZZLE_Y),
            ureg_scalar(ureg_src(tmp), TGSI_SWIZZLE_X), ureg_imm1f(shader, -0.25f));
   ureg_MAD(shader, ureg_writemask(o_vbottom, TGSI_WRITEMASK_Z), ureg_scalar(vtex, TGSI_SWIZZLE_Y),
            ureg_scalar(ureg_src(tmp), TGSI_SWIZZLE_Y), ureg_imm1f(shader, -0.25f));
   ureg_RCP(shader, ureg_writemask(o_vbottom, TGSI_WRITEMASK_W),
            ureg_scalar(ureg_src(tmp), TGSI_SWIZZLE_Y));

   ureg_END(shader);

   return ureg_create_shader_and_destroy(shader, c->pipe);
}

static void
create_frag_shader_weave(struct ureg_program *shader, struct ureg_dst fragment)
{
   struct ureg_src i_tc[2];
   struct ureg_src sampler[3];
   struct ureg_dst t_tc[2];
   struct ureg_dst t_texel[2];
   unsigned i, j;

   i_tc[0] = ureg_DECL_fs_input(shader, TGSI_SEMANTIC_GENERIC, VS_O_VTOP, TGSI_INTERPOLATE_LINEAR);
   i_tc[1] = ureg_DECL_fs_input(shader, TGSI_SEMANTIC_GENERIC, VS_O_VBOTTOM, TGSI_INTERPOLATE_LINEAR);

   for (i = 0; i < 3; ++i) {
      sampler[i] = ureg_DECL_sampler(shader, i);
      ureg_DECL_sampler_view(shader, i, TGSI_TEXTURE_2D_ARRAY,
                             TGSI_RETURN_TYPE_FLOAT,
                             TGSI_RETURN_TYPE_FLOAT,
                             TGSI_RETURN_TYPE_FLOAT,
                             TGSI_RETURN_TYPE_FLOAT);
   }

   for (i = 0; i < 2; ++i) {
      t_tc[i] = ureg_DECL_temporary(shader);
      t_texel[i] = ureg_DECL_temporary(shader);
   }

   /* calculate the texture offsets
    * t_tc.x = i_tc.x
    * t_tc.y = (round(i_tc.y - 0.5) + 0.5) / height * 2
    */
   for (i = 0; i < 2; ++i) {
      ureg_MOV(shader, ureg_writemask(t_tc[i], TGSI_WRITEMASK_X), i_tc[i]);
      ureg_ADD(shader, ureg_writemask(t_tc[i], TGSI_WRITEMASK_YZ),
               i_tc[i], ureg_imm1f(shader, -0.5f));
      ureg_ROUND(shader, ureg_writemask(t_tc[i], TGSI_WRITEMASK_YZ), ureg_src(t_tc[i]));
      ureg_MOV(shader, ureg_writemask(t_tc[i], TGSI_WRITEMASK_W),
               ureg_imm1f(shader, i ? 1.0f : 0.0f));
      ureg_ADD(shader, ureg_writemask(t_tc[i], TGSI_WRITEMASK_YZ),
               ureg_src(t_tc[i]), ureg_imm1f(shader, 0.5f));
      ureg_MUL(shader, ureg_writemask(t_tc[i], TGSI_WRITEMASK_Y),
               ureg_src(t_tc[i]), ureg_scalar(i_tc[0], TGSI_SWIZZLE_W));
      ureg_MUL(shader, ureg_writemask(t_tc[i], TGSI_WRITEMASK_Z),
               ureg_src(t_tc[i]), ureg_scalar(i_tc[1], TGSI_SWIZZLE_W));
   }

   /* fetch the texels
    * texel[0..1].x = tex(t_tc[0..1][0])
    * texel[0..1].y = tex(t_tc[0..1][1])
    * texel[0..1].z = tex(t_tc[0..1][2])
    */
   for (i = 0; i < 2; ++i)
      for (j = 0; j < 3; ++j) {
         struct ureg_src src = ureg_swizzle(ureg_src(t_tc[i]),
            TGSI_SWIZZLE_X, j ? TGSI_SWIZZLE_Z : TGSI_SWIZZLE_Y, TGSI_SWIZZLE_W, TGSI_SWIZZLE_W);

         ureg_TEX(shader, ureg_writemask(t_texel[i], TGSI_WRITEMASK_X << j),
                  TGSI_TEXTURE_2D_ARRAY, src, sampler[j]);
      }

   /* calculate linear interpolation factor
    * factor = |round(i_tc.y) - i_tc.y| * 2
    */
   ureg_ROUND(shader, ureg_writemask(t_tc[0], TGSI_WRITEMASK_YZ), i_tc[0]);
   ureg_ADD(shader, ureg_writemask(t_tc[0], TGSI_WRITEMASK_YZ),
            ureg_src(t_tc[0]), ureg_negate(i_tc[0]));
   ureg_MUL(shader, ureg_writemask(t_tc[0], TGSI_WRITEMASK_YZ),
            ureg_abs(ureg_src(t_tc[0])), ureg_imm1f(shader, 2.0f));
   ureg_LRP(shader, fragment, ureg_swizzle(ureg_src(t_tc[0]),
            TGSI_SWIZZLE_Y, TGSI_SWIZZLE_Z, TGSI_SWIZZLE_Z, TGSI_SWIZZLE_Z),
            ureg_src(t_texel[0]), ureg_src(t_texel[1]));

   for (i = 0; i < 2; ++i) {
      ureg_release_temporary(shader, t_texel[i]);
      ureg_release_temporary(shader, t_tc[i]);
   }
}

static void
create_frag_shader_csc(struct ureg_program *shader, struct ureg_dst texel,
		       struct ureg_dst fragment)
{
   struct ureg_src csc[3];
   struct ureg_src lumakey;
   struct ureg_dst temp[2];
   unsigned i;

   for (i = 0; i < 3; ++i)
      csc[i] = ureg_DECL_constant(shader, i);

   lumakey = ureg_DECL_constant(shader, 3);

   for (i = 0; i < 2; ++i)
      temp[i] = ureg_DECL_temporary(shader);

   ureg_MOV(shader, ureg_writemask(texel, TGSI_WRITEMASK_W),
	    ureg_imm1f(shader, 1.0f));

   for (i = 0; i < 3; ++i)
      ureg_DP4(shader, ureg_writemask(fragment, TGSI_WRITEMASK_X << i), csc[i],
	       ureg_src(texel));

   ureg_MOV(shader, ureg_writemask(temp[0], TGSI_WRITEMASK_W),
            ureg_scalar(ureg_src(texel), TGSI_SWIZZLE_Z));
   ureg_SLE(shader, ureg_writemask(temp[1], TGSI_WRITEMASK_W),
            ureg_src(temp[0]), ureg_scalar(lumakey, TGSI_SWIZZLE_X));
   ureg_SGT(shader, ureg_writemask(temp[0], TGSI_WRITEMASK_W),
            ureg_src(temp[0]), ureg_scalar(lumakey, TGSI_SWIZZLE_Y));
   ureg_MAX(shader, ureg_writemask(fragment, TGSI_WRITEMASK_W),
            ureg_src(temp[0]), ureg_src(temp[1]));

   for (i = 0; i < 2; ++i)
       ureg_release_temporary(shader, temp[i]);
}

static void
create_frag_shader_yuv(struct ureg_program *shader, struct ureg_dst texel)
{
   struct ureg_src tc;
   struct ureg_src sampler[3];
   unsigned i;

   tc = ureg_DECL_fs_input(shader, TGSI_SEMANTIC_GENERIC, VS_O_VTEX, TGSI_INTERPOLATE_LINEAR);
   for (i = 0; i < 3; ++i) {
      sampler[i] = ureg_DECL_sampler(shader, i);
      ureg_DECL_sampler_view(shader, i, TGSI_TEXTURE_2D_ARRAY,
                             TGSI_RETURN_TYPE_FLOAT,
                             TGSI_RETURN_TYPE_FLOAT,
                             TGSI_RETURN_TYPE_FLOAT,
                             TGSI_RETURN_TYPE_FLOAT);
   }

   /*
    * texel.xyz = tex(tc, sampler[i])
    */
   for (i = 0; i < 3; ++i)
      ureg_TEX(shader, ureg_writemask(texel, TGSI_WRITEMASK_X << i), TGSI_TEXTURE_2D_ARRAY, tc, sampler[i]);
}

void *
create_frag_shader_video_buffer(struct vl_compositor *c)
{
   struct ureg_program *shader;
   struct ureg_dst texel;
   struct ureg_dst fragment;

   shader = ureg_create(PIPE_SHADER_FRAGMENT);
   if (!shader)
      return false;

   texel = ureg_DECL_temporary(shader);
   fragment = ureg_DECL_output(shader, TGSI_SEMANTIC_COLOR, 0);

   create_frag_shader_yuv(shader, texel);
   create_frag_shader_csc(shader, texel, fragment);

   ureg_release_temporary(shader, texel);
   ureg_END(shader);

   return ureg_create_shader_and_destroy(shader, c->pipe);
}

void *
create_frag_shader_weave_rgb(struct vl_compositor *c)
{
   struct ureg_program *shader;
   struct ureg_dst texel, fragment;

   shader = ureg_create(PIPE_SHADER_FRAGMENT);
   if (!shader)
      return false;

   texel = ureg_DECL_temporary(shader);
   fragment = ureg_DECL_output(shader, TGSI_SEMANTIC_COLOR, 0);

   create_frag_shader_weave(shader, texel);
   create_frag_shader_csc(shader, texel, fragment);

   ureg_release_temporary(shader, texel);

   ureg_END(shader);

   return ureg_create_shader_and_destroy(shader, c->pipe);
}

void *
create_frag_shader_deint_yuv(struct vl_compositor *c, bool y, bool w)
{
   struct ureg_program *shader;
   struct ureg_dst texel, fragment;

   shader = ureg_create(PIPE_SHADER_FRAGMENT);
   if (!shader)
      return false;

   texel = ureg_DECL_temporary(shader);
   fragment = ureg_DECL_output(shader, TGSI_SEMANTIC_COLOR, 0);

   if (w)
      create_frag_shader_weave(shader, texel);
   else
      create_frag_shader_yuv(shader, texel);

   if (y)
      ureg_MOV(shader, ureg_writemask(fragment, TGSI_WRITEMASK_X), ureg_src(texel));
   else
      ureg_MOV(shader, ureg_writemask(fragment, TGSI_WRITEMASK_XY),
                       ureg_swizzle(ureg_src(texel), TGSI_SWIZZLE_Y,
                               TGSI_SWIZZLE_Z, TGSI_SWIZZLE_W, TGSI_SWIZZLE_W));

   ureg_release_temporary(shader, texel);

   ureg_END(shader);

   return ureg_create_shader_and_destroy(shader, c->pipe);
}

void *
create_frag_shader_palette(struct vl_compositor *c, bool include_cc)
{
   struct ureg_program *shader;
   struct ureg_src csc[3];
   struct ureg_src tc;
   struct ureg_src sampler;
   struct ureg_src palette;
   struct ureg_dst texel;
   struct ureg_dst fragment;
   unsigned i;

   shader = ureg_create(PIPE_SHADER_FRAGMENT);
   if (!shader)
      return false;

   for (i = 0; include_cc && i < 3; ++i)
      csc[i] = ureg_DECL_constant(shader, i);

   tc = ureg_DECL_fs_input(shader, TGSI_SEMANTIC_GENERIC, VS_O_VTEX, TGSI_INTERPOLATE_LINEAR);
   sampler = ureg_DECL_sampler(shader, 0);
   ureg_DECL_sampler_view(shader, 0, TGSI_TEXTURE_2D,
                          TGSI_RETURN_TYPE_FLOAT,
                          TGSI_RETURN_TYPE_FLOAT,
                          TGSI_RETURN_TYPE_FLOAT,
                          TGSI_RETURN_TYPE_FLOAT);
   palette = ureg_DECL_sampler(shader, 1);
   ureg_DECL_sampler_view(shader, 1, TGSI_TEXTURE_1D,
                          TGSI_RETURN_TYPE_FLOAT,
                          TGSI_RETURN_TYPE_FLOAT,
                          TGSI_RETURN_TYPE_FLOAT,
                          TGSI_RETURN_TYPE_FLOAT);

   texel = ureg_DECL_temporary(shader);
   fragment = ureg_DECL_output(shader, TGSI_SEMANTIC_COLOR, 0);

   /*
    * texel = tex(tc, sampler)
    * fragment.xyz = tex(texel, palette) * csc
    * fragment.a = texel.a
    */
   ureg_TEX(shader, texel, TGSI_TEXTURE_2D, tc, sampler);
   ureg_MOV(shader, ureg_writemask(fragment, TGSI_WRITEMASK_W), ureg_src(texel));

   if (include_cc) {
      ureg_TEX(shader, texel, TGSI_TEXTURE_1D, ureg_src(texel), palette);
      for (i = 0; i < 3; ++i)
         ureg_DP4(shader, ureg_writemask(fragment, TGSI_WRITEMASK_X << i), csc[i], ureg_src(texel));
   } else {
      ureg_TEX(shader, ureg_writemask(fragment, TGSI_WRITEMASK_XYZ),
               TGSI_TEXTURE_1D, ureg_src(texel), palette);
   }

   ureg_release_temporary(shader, texel);
   ureg_END(shader);

   return ureg_create_shader_and_destroy(shader, c->pipe);
}

void *
create_frag_shader_rgba(struct vl_compositor *c)
{
   struct ureg_program *shader;
   struct ureg_src tc, color, sampler;
   struct ureg_dst texel, fragment;

   shader = ureg_create(PIPE_SHADER_FRAGMENT);
   if (!shader)
      return false;

   tc = ureg_DECL_fs_input(shader, TGSI_SEMANTIC_GENERIC, VS_O_VTEX, TGSI_INTERPOLATE_LINEAR);
   color = ureg_DECL_fs_input(shader, TGSI_SEMANTIC_COLOR, VS_O_COLOR, TGSI_INTERPOLATE_LINEAR);
   sampler = ureg_DECL_sampler(shader, 0);
   ureg_DECL_sampler_view(shader, 0, TGSI_TEXTURE_2D,
                          TGSI_RETURN_TYPE_FLOAT,
                          TGSI_RETURN_TYPE_FLOAT,
                          TGSI_RETURN_TYPE_FLOAT,
                          TGSI_RETURN_TYPE_FLOAT);
   texel = ureg_DECL_temporary(shader);
   fragment = ureg_DECL_output(shader, TGSI_SEMANTIC_COLOR, 0);

   /*
    * fragment = tex(tc, sampler)
    */
   ureg_TEX(shader, texel, TGSI_TEXTURE_2D, tc, sampler);
   ureg_MUL(shader, fragment, ureg_src(texel), color);
   ureg_END(shader);

   return ureg_create_shader_and_destroy(shader, c->pipe);
}

void *
create_frag_shader_rgb_yuv(struct vl_compositor *c, bool y)
{
   struct ureg_program *shader;
   struct ureg_src tc, sampler;
   struct ureg_dst texel, fragment;

   struct ureg_src csc[3];
   unsigned i;

   shader = ureg_create(PIPE_SHADER_FRAGMENT);
   if (!shader)
      return false;

   for (i = 0; i < 3; ++i)
      csc[i] = ureg_DECL_constant(shader, i);

   sampler = ureg_DECL_sampler(shader, 0);
   tc = ureg_DECL_fs_input(shader, TGSI_SEMANTIC_GENERIC, VS_O_VTEX, TGSI_INTERPOLATE_LINEAR);
   texel = ureg_DECL_temporary(shader);
   fragment = ureg_DECL_output(shader, TGSI_SEMANTIC_COLOR, 0);

   ureg_TEX(shader, texel, TGSI_TEXTURE_2D, tc, sampler);

   if (y) {
      ureg_DP4(shader, ureg_writemask(fragment, TGSI_WRITEMASK_X), csc[0], ureg_src(texel));
   } else {
      for (i = 0; i < 2; ++i)
         ureg_DP4(shader, ureg_writemask(fragment, TGSI_WRITEMASK_X << i), csc[i + 1], ureg_src(texel));
   }

   ureg_release_temporary(shader, texel);
   ureg_END(shader);

   return ureg_create_shader_and_destroy(shader, c->pipe);
}

static void
gen_rect_verts(struct vertex2f *vb, struct vl_compositor_layer *layer)
{
   struct vertex2f tl, tr, br, bl;

   assert(vb && layer);

   switch (layer->rotate) {
   default:
   case VL_COMPOSITOR_ROTATE_0:
      tl = layer->dst.tl;
      tr.x = layer->dst.br.x;
      tr.y = layer->dst.tl.y;
      br = layer->dst.br;
      bl.x = layer->dst.tl.x;
      bl.y = layer->dst.br.y;
      break;
   case VL_COMPOSITOR_ROTATE_90:
      tl.x = layer->dst.br.x;
      tl.y = layer->dst.tl.y;
      tr = layer->dst.br;
      br.x = layer->dst.tl.x;
      br.y = layer->dst.br.y;
      bl = layer->dst.tl;
      break;
   case VL_COMPOSITOR_ROTATE_180:
      tl = layer->dst.br;
      tr.x = layer->dst.tl.x;
      tr.y = layer->dst.br.y;
      br = layer->dst.tl;
      bl.x = layer->dst.br.x;
      bl.y = layer->dst.tl.y;
      break;
   case VL_COMPOSITOR_ROTATE_270:
      tl.x = layer->dst.tl.x;
      tl.y = layer->dst.br.y;
      tr = layer->dst.tl;
      br.x = layer->dst.br.x;
      br.y = layer->dst.tl.y;
      bl = layer->dst.br;
      break;
   }

   vb[ 0].x = tl.x;
   vb[ 0].y = tl.y;
   vb[ 1].x = layer->src.tl.x;
   vb[ 1].y = layer->src.tl.y;
   vb[ 2] = layer->zw;
   vb[ 3].x = layer->colors[0].x;
   vb[ 3].y = layer->colors[0].y;
   vb[ 4].x = layer->colors[0].z;
   vb[ 4].y = layer->colors[0].w;

   vb[ 5].x = tr.x;
   vb[ 5].y = tr.y;
   vb[ 6].x = layer->src.br.x;
   vb[ 6].y = layer->src.tl.y;
   vb[ 7] = layer->zw;
   vb[ 8].x = layer->colors[1].x;
   vb[ 8].y = layer->colors[1].y;
   vb[ 9].x = layer->colors[1].z;
   vb[ 9].y = layer->colors[1].w;

   vb[10].x = br.x;
   vb[10].y = br.y;
   vb[11].x = layer->src.br.x;
   vb[11].y = layer->src.br.y;
   vb[12] = layer->zw;
   vb[13].x = layer->colors[2].x;
   vb[13].y = layer->colors[2].y;
   vb[14].x = layer->colors[2].z;
   vb[14].y = layer->colors[2].w;

   vb[15].x = bl.x;
   vb[15].y = bl.y;
   vb[16].x = layer->src.tl.x;
   vb[16].y = layer->src.br.y;
   vb[17] = layer->zw;
   vb[18].x = layer->colors[3].x;
   vb[18].y = layer->colors[3].y;
   vb[19].x = layer->colors[3].z;
   vb[19].y = layer->colors[3].w;
}

static inline struct u_rect
calc_drawn_area(struct vl_compositor_state *s, struct vl_compositor_layer *layer)
{
   struct vertex2f tl, br;
   struct u_rect result;

   assert(s && layer);

   // rotate
   switch (layer->rotate) {
   default:
   case VL_COMPOSITOR_ROTATE_0:
      tl = layer->dst.tl;
      br = layer->dst.br;
      break;
   case VL_COMPOSITOR_ROTATE_90:
      tl.x = layer->dst.br.x;
      tl.y = layer->dst.tl.y;
      br.x = layer->dst.tl.x;
      br.y = layer->dst.br.y;
      break;
   case VL_COMPOSITOR_ROTATE_180:
      tl = layer->dst.br;
      br = layer->dst.tl;
      break;
   case VL_COMPOSITOR_ROTATE_270:
      tl.x = layer->dst.tl.x;
      tl.y = layer->dst.br.y;
      br.x = layer->dst.br.x;
      br.y = layer->dst.tl.y;
      break;
   }

   // scale
   result.x0 = tl.x * layer->viewport.scale[0] + layer->viewport.translate[0];
   result.y0 = tl.y * layer->viewport.scale[1] + layer->viewport.translate[1];
   result.x1 = br.x * layer->viewport.scale[0] + layer->viewport.translate[0];
   result.y1 = br.y * layer->viewport.scale[1] + layer->viewport.translate[1];

   // and clip
   result.x0 = MAX2(result.x0, s->scissor.minx);
   result.y0 = MAX2(result.y0, s->scissor.miny);
   result.x1 = MIN2(result.x1, s->scissor.maxx);
   result.y1 = MIN2(result.y1, s->scissor.maxy);
   return result;
}

static void
gen_vertex_data(struct vl_compositor *c, struct vl_compositor_state *s, struct u_rect *dirty)
{
   struct vertex2f *vb;
   unsigned i;

   assert(c);

   /* Allocate new memory for vertices. */
   u_upload_alloc(c->pipe->stream_uploader, 0,
                  c->vertex_buf.stride * VL_COMPOSITOR_MAX_LAYERS * 4, /* size */
                  4, /* alignment */
                  &c->vertex_buf.buffer_offset, &c->vertex_buf.buffer.resource,
                  (void **)&vb);

   for (i = 0; i < VL_COMPOSITOR_MAX_LAYERS; i++) {
      if (s->used_layers & (1 << i)) {
         struct vl_compositor_layer *layer = &s->layers[i];
         gen_rect_verts(vb, layer);
         vb += 20;

         if (!layer->viewport_valid) {
            layer->viewport.scale[0] = c->fb_state.width;
            layer->viewport.scale[1] = c->fb_state.height;
            layer->viewport.translate[0] = 0;
            layer->viewport.translate[1] = 0;
         }

         if (dirty && layer->clearing) {
            struct u_rect drawn = calc_drawn_area(s, layer);
            if (
             dirty->x0 >= drawn.x0 &&
             dirty->y0 >= drawn.y0 &&
             dirty->x1 <= drawn.x1 &&
             dirty->y1 <= drawn.y1) {

               // We clear the dirty area anyway, no need for clear_render_target
               dirty->x0 = dirty->y0 = VL_COMPOSITOR_MAX_DIRTY;
               dirty->x1 = dirty->y1 = VL_COMPOSITOR_MIN_DIRTY;
            }
         }
      }
   }

   u_upload_unmap(c->pipe->stream_uploader);
}

static void
draw_layers(struct vl_compositor *c, struct vl_compositor_state *s, struct u_rect *dirty)
{
   unsigned vb_index, i;

   assert(c);

   for (i = 0, vb_index = 0; i < VL_COMPOSITOR_MAX_LAYERS; ++i) {
      if (s->used_layers & (1 << i)) {
         struct vl_compositor_layer *layer = &s->layers[i];
         struct pipe_sampler_view **samplers = &layer->sampler_views[0];
         unsigned num_sampler_views = !samplers[1] ? 1 : !samplers[2] ? 2 : 3;
         void *blend = layer->blend ? layer->blend : i ? c->blend_add : c->blend_clear;

         c->pipe->bind_blend_state(c->pipe, blend);
         c->pipe->set_viewport_states(c->pipe, 0, 1, &layer->viewport);
         c->pipe->bind_fs_state(c->pipe, layer->fs);
         c->pipe->bind_sampler_states(c->pipe, PIPE_SHADER_FRAGMENT, 0,
                                      num_sampler_views, layer->samplers);
         c->pipe->set_sampler_views(c->pipe, PIPE_SHADER_FRAGMENT, 0,
                                    num_sampler_views, 0, false, samplers);

         util_draw_arrays(c->pipe, PIPE_PRIM_QUADS, vb_index * 4, 4);
         vb_index++;

         if (dirty) {
            // Remember the currently drawn area as dirty for the next draw command
            struct u_rect drawn = calc_drawn_area(s, layer);
            dirty->x0 = MIN2(drawn.x0, dirty->x0);
            dirty->y0 = MIN2(drawn.y0, dirty->y0);
            dirty->x1 = MAX2(drawn.x1, dirty->x1);
            dirty->y1 = MAX2(drawn.y1, dirty->y1);
         }
      }
   }
}

void
vl_compositor_gfx_render(struct vl_compositor_state *s,
                     struct vl_compositor           *c,
                     struct pipe_surface            *dst_surface,
                     struct u_rect                  *dirty_area,
                     bool                            clear_dirty)
{
   assert(c);
   assert(dst_surface);

   c->fb_state.width = dst_surface->width;
   c->fb_state.height = dst_surface->height;
   c->fb_state.cbufs[0] = dst_surface;

   if (!s->scissor_valid) {
      s->scissor.minx = 0;
      s->scissor.miny = 0;
      s->scissor.maxx = dst_surface->width;
      s->scissor.maxy = dst_surface->height;
   }
   c->pipe->set_scissor_states(c->pipe, 0, 1, &s->scissor);

   gen_vertex_data(c, s, dirty_area);

   if (clear_dirty && dirty_area &&
       (dirty_area->x0 < dirty_area->x1 || dirty_area->y0 < dirty_area->y1)) {

      c->pipe->clear_render_target(c->pipe, dst_surface, &s->clear_color,
                                   0, 0, dst_surface->width, dst_surface->height, false);
      dirty_area->x0 = dirty_area->y0 = VL_COMPOSITOR_MAX_DIRTY;
      dirty_area->x1 = dirty_area->y1 = VL_COMPOSITOR_MIN_DIRTY;
   }

   c->pipe->set_framebuffer_state(c->pipe, &c->fb_state);
   c->pipe->bind_vs_state(c->pipe, c->vs);
   c->pipe->set_vertex_buffers(c->pipe, 0, 1, 0, false, &c->vertex_buf);
   c->pipe->bind_vertex_elements_state(c->pipe, c->vertex_elems_state);
   pipe_set_constant_buffer(c->pipe, PIPE_SHADER_FRAGMENT, 0, s->shader_params);
   c->pipe->bind_rasterizer_state(c->pipe, c->rast);

   draw_layers(c, s, dirty_area);
}