/**********************************************************
 * Copyright 2008-2009 VMware, Inc.  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, 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 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.
 *
 **********************************************************/

#include "pipe/p_inlines.h"
#include "pipe/p_defines.h"
#include "util/u_math.h"

#include "svga_context.h"
#include "svga_state.h"
#include "svga_cmd.h"
#include "svga_debug.h"


/***********************************************************************
 * Hardware state update
 */


static int emit_framebuffer( struct svga_context *svga,
                             unsigned dirty )
{
   const struct pipe_framebuffer_state *curr = &svga->curr.framebuffer;
   struct pipe_framebuffer_state *hw = &svga->state.hw_clear.framebuffer;
   unsigned i;
   enum pipe_error ret;

   /* XXX: Need shadow state in svga->hw to eliminate redundant
    * uploads, especially of NULL buffers.
    */
   
   for(i = 0; i < PIPE_MAX_COLOR_BUFS; ++i) {
      if (curr->cbufs[i] != hw->cbufs[i]) {
         if (svga->curr.nr_fbs++ > 8)
            return PIPE_ERROR_OUT_OF_MEMORY;

         ret = SVGA3D_SetRenderTarget(svga->swc, SVGA3D_RT_COLOR0 + i, curr->cbufs[i]);
         if (ret != PIPE_OK)
            return ret;
         
         pipe_surface_reference(&hw->cbufs[i], curr->cbufs[i]);
      }
   }

   
   if (curr->zsbuf != hw->zsbuf) {
      ret = SVGA3D_SetRenderTarget(svga->swc, SVGA3D_RT_DEPTH, curr->zsbuf);
      if (ret != PIPE_OK)
         return ret;

      if (curr->zsbuf &&
          curr->zsbuf->format == PIPE_FORMAT_Z24S8_UNORM) {
         ret = SVGA3D_SetRenderTarget(svga->swc, SVGA3D_RT_STENCIL, curr->zsbuf);
         if (ret != PIPE_OK)
            return ret;
      }
      else {
         ret = SVGA3D_SetRenderTarget(svga->swc, SVGA3D_RT_STENCIL, NULL);
         if (ret != PIPE_OK)
            return ret;
      }
      
      pipe_surface_reference(&hw->zsbuf, curr->zsbuf);
   }


   return 0;
}


struct svga_tracked_state svga_hw_framebuffer = 
{
   "hw framebuffer state",
   SVGA_NEW_FRAME_BUFFER,
   emit_framebuffer
};




/*********************************************************************** 
 */

static int emit_viewport( struct svga_context *svga,
                          unsigned dirty )
{
   const struct pipe_viewport_state *viewport = &svga->curr.viewport;
   struct svga_prescale prescale;
   SVGA3dRect rect;
   /* Not sure if this state is relevant with POSITIONT.  Probably
    * not, but setting to 0,1 avoids some state pingponging.
    */
   float range_min = 0.0;
   float range_max = 1.0;
   float flip = -1.0;
   boolean degenerate = FALSE;
   enum pipe_error ret;

   float fb_width = svga->curr.framebuffer.width;
   float fb_height = svga->curr.framebuffer.height;

   memset( &prescale, 0, sizeof(prescale) );

   if (svga->curr.rast->templ.bypass_vs_clip_and_viewport) {

      /* Avoid POSITIONT as it has a non trivial implementation outside the D3D
       * API. Always generate a vertex shader.
       */
      rect.x = 0;
      rect.y = 0;
      rect.w = svga->curr.framebuffer.width;
      rect.h = svga->curr.framebuffer.height;

      prescale.scale[0] = 2.0 / (float)rect.w;
      prescale.scale[1] = - 2.0 / (float)rect.h;
      prescale.scale[2] = 1.0;
      prescale.scale[3] = 1.0;
      prescale.translate[0] = -1.0f;
      prescale.translate[1] = 1.0f;
      prescale.translate[2] = 0;
      prescale.translate[3] = 0;
      prescale.enabled = TRUE;
   } else {

      /* Examine gallium viewport transformation and produce a screen
       * rectangle and possibly vertex shader pre-transformation to
       * get the same results.
       */
      float fx =        viewport->scale[0] * -1.0 + viewport->translate[0];
      float fy = flip * viewport->scale[1] * -1.0 + viewport->translate[1];
      float fw =        viewport->scale[0] * 2; 
      float fh = flip * viewport->scale[1] * 2; 

      SVGA_DBG(DEBUG_VIEWPORT,
               "\ninitial %f,%f %fx%f\n",
               fx,
               fy,
               fw,
               fh);

      prescale.scale[0] = 1.0;
      prescale.scale[1] = 1.0;
      prescale.scale[2] = 1.0;
      prescale.scale[3] = 1.0;
      prescale.translate[0] = 0;
      prescale.translate[1] = 0;
      prescale.translate[2] = 0;
      prescale.translate[3] = 0;
      prescale.enabled = TRUE;



      if (fw < 0) {
         prescale.scale[0] *= -1.0;
         prescale.translate[0] += -fw;
         fw = -fw;
         fx =        viewport->scale[0] * 1.0 + viewport->translate[0];
      }

      if (fh < 0) {
         prescale.scale[1] *= -1.0;
         prescale.translate[1] += -fh;
         fh = -fh;
         fy = flip * viewport->scale[1] * 1.0 + viewport->translate[1];
      }

      if (fx < 0) {
         prescale.translate[0] += fx;
         prescale.scale[0] *= fw / (fw + fx); 
         fw += fx;
         fx = 0;
      }

      if (fy < 0) {
         prescale.translate[1] += fy;
         prescale.scale[1] *= fh / (fh + fy); 
         fh += fy;
         fy = 0;
      }

      if (fx + fw > fb_width) {
         prescale.scale[0] *= fw / (fb_width - fx); 
         prescale.translate[0] -= fx * (fw / (fb_width - fx));
         prescale.translate[0] += fx;
         fw = fb_width - fx;
         
      }

      if (fy + fh > fb_height) {
         prescale.scale[1] *= fh / (fb_height - fy);
         prescale.translate[1] -= fy * (fh / (fb_height - fy));
         prescale.translate[1] += fy;
         fh = fb_height - fy;
      }

      if (fw < 0 || fh < 0) {
         fw = fh = fx = fy = 0;
         degenerate = TRUE;
         goto out;
      }


      /* D3D viewport is integer space.  Convert fx,fy,etc. to
       * integers.
       *
       * TODO: adjust pretranslate correct for any subpixel error
       * introduced converting to integers.
       */
      rect.x = fx;
      rect.y = fy;
      rect.w = fw;
      rect.h = fh;

      SVGA_DBG(DEBUG_VIEWPORT,
               "viewport error %f,%f %fx%f\n",
               fabs((float)rect.x - fx),
               fabs((float)rect.y - fy),
               fabs((float)rect.w - fw),
               fabs((float)rect.h - fh));

      SVGA_DBG(DEBUG_VIEWPORT,
               "viewport %d,%d %dx%d\n",
               rect.x,
               rect.y,
               rect.w,
               rect.h);
      

      /* Finally, to get GL rasterization rules, need to tweak the
       * screen-space coordinates slightly relative to D3D which is
       * what hardware implements natively.
       */
      if (svga->curr.rast->templ.gl_rasterization_rules) {
         float adjust_x = 0.0;
         float adjust_y = 0.0;

         switch (svga->curr.reduced_prim) {
         case PIPE_PRIM_LINES:
            adjust_x = -0.5;
            adjust_y = 0;
            break;
         case PIPE_PRIM_POINTS:
         case PIPE_PRIM_TRIANGLES:
            adjust_x = -0.375;
            adjust_y = -0.5;
            break;
         }

         prescale.translate[0] += adjust_x;
         prescale.translate[1] += adjust_y;
         prescale.translate[2] = 0.5; /* D3D clip space */
         prescale.scale[2]     = 0.5; /* D3D clip space */
      }


      range_min = viewport->scale[2] * -1.0 + viewport->translate[2];
      range_max = viewport->scale[2] *  1.0 + viewport->translate[2];

      /* D3D (and by implication SVGA) doesn't like dealing with zmax
       * less than zmin.  Detect that case, flip the depth range and
       * invert our z-scale factor to achieve the same effect.
       */
      if (range_min > range_max) {
         float range_tmp;
         range_tmp = range_min; 
         range_min = range_max; 
         range_max = range_tmp;
         prescale.scale[2]     = -prescale.scale[2];
      }
   }

   if (prescale.enabled) {
      float H[2];
      float J[2];
      int i;

      SVGA_DBG(DEBUG_VIEWPORT,
               "prescale %f,%f %fx%f\n",
               prescale.translate[0],
               prescale.translate[1],
               prescale.scale[0],
               prescale.scale[1]);

      H[0] = (float)rect.w / 2.0;
      H[1] = -(float)rect.h / 2.0;
      J[0] = (float)rect.x + (float)rect.w / 2.0;
      J[1] = (float)rect.y + (float)rect.h / 2.0;

      SVGA_DBG(DEBUG_VIEWPORT,
               "H %f,%f\n"
               "J %fx%f\n",
               H[0],
               H[1],
               J[0],
               J[1]);

      /* Adjust prescale to take into account the fact that it is
       * going to be applied prior to the perspective divide and
       * viewport transformation.
       * 
       * Vwin = H(Vc/Vc.w) + J
       *
       * We want to tweak Vwin with scale and translation from above,
       * as in:
       *
       * Vwin' = S Vwin + T
       *
       * But we can only modify the values at Vc.  Plugging all the
       * above together, and rearranging, eventually we get:
       *
       *   Vwin' = H(Vc'/Vc'.w) + J
       * where:
       *   Vc' = SVc + KVc.w
       *   K = (T + (S-1)J) / H
       *
       * Overwrite prescale.translate with values for K:
       */
      for (i = 0; i < 2; i++) {
         prescale.translate[i] = ((prescale.translate[i] +
                                   (prescale.scale[i] - 1.0) * J[i]) / H[i]);
      }

      SVGA_DBG(DEBUG_VIEWPORT,
               "clipspace %f,%f %fx%f\n",
               prescale.translate[0],
               prescale.translate[1],
               prescale.scale[0],
               prescale.scale[1]);
   }

out:
   if (degenerate) {
      rect.x = 0;
      rect.y = 0;
      rect.w = 1;
      rect.h = 1;
      prescale.enabled = FALSE;
   }

   if (memcmp(&rect, &svga->state.hw_clear.viewport, sizeof(rect)) != 0) {
      ret = SVGA3D_SetViewport(svga->swc, &rect);
      if(ret != PIPE_OK)
         return ret;

      memcpy(&svga->state.hw_clear.viewport, &rect, sizeof(rect));
      assert(sizeof(rect) == sizeof(svga->state.hw_clear.viewport));
   }

   if (svga->state.hw_clear.depthrange.zmin != range_min ||
       svga->state.hw_clear.depthrange.zmax != range_max) 
   {
      ret = SVGA3D_SetZRange(svga->swc, range_min, range_max );
      if(ret != PIPE_OK)
         return ret;

      svga->state.hw_clear.depthrange.zmin = range_min;
      svga->state.hw_clear.depthrange.zmax = range_max;
   }

   if (memcmp(&prescale, &svga->state.hw_clear.prescale, sizeof prescale) != 0) {
      svga->dirty |= SVGA_NEW_PRESCALE;
      svga->state.hw_clear.prescale = prescale;
   }

   return 0;
}


struct svga_tracked_state svga_hw_viewport = 
{
   "hw viewport state",
   ( SVGA_NEW_FRAME_BUFFER |
     SVGA_NEW_VIEWPORT |
     SVGA_NEW_RAST |
     SVGA_NEW_REDUCED_PRIMITIVE ),
   emit_viewport
};


/***********************************************************************
 * Scissor state
 */
static int emit_scissor_rect( struct svga_context *svga,
                              unsigned dirty )
{
   const struct pipe_scissor_state *scissor = &svga->curr.scissor;
   SVGA3dRect rect;

   rect.x = scissor->minx;
   rect.y = scissor->miny;
   rect.w = scissor->maxx - scissor->minx; /* + 1 ?? */
   rect.h = scissor->maxy - scissor->miny; /* + 1 ?? */
   
   return SVGA3D_SetScissorRect(svga->swc, &rect);
}


struct svga_tracked_state svga_hw_scissor = 
{
   "hw scissor state",
   SVGA_NEW_SCISSOR,
   emit_scissor_rect
};


/***********************************************************************
 * Userclip state
 */

static int emit_clip_planes( struct svga_context *svga,
                             unsigned dirty )
{
   unsigned i;
   enum pipe_error ret;

   /* TODO: just emit directly from svga_set_clip_state()?
    */
   for (i = 0; i < svga->curr.clip.nr; i++) {
      ret = SVGA3D_SetClipPlane( svga->swc,
                                 i,
                                 svga->curr.clip.ucp[i] );
      if(ret != PIPE_OK)
         return ret;
   }

   return 0;
}


struct svga_tracked_state svga_hw_clip_planes = 
{
   "hw viewport state",
   SVGA_NEW_CLIP,
   emit_clip_planes
};
