path: root/src/mesa/pipe/softpipe/sp_quad_fs.c

/*
 * Mesa 3-D graphics library
 * Version:  6.5
 *
 * Copyright (C) 1999-2005  Brian Paul   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
 * BRIAN PAUL 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.
 */

/* Vertices are just an array of floats, with all the attributes
 * packed.  We currently assume a layout like:
 *
 * attr[0][0..3] - window position
 * attr[1..n][0..3] - remaining attributes.
 *
 * Attributes are assumed to be 4 floats wide but are packed so that
 * all the enabled attributes run contiguously.
 */

#include "glheader.h"
#include "imports.h"
#include "sp_context.h"
#include "sp_headers.h"
#include "sp_quad.h"
#include "core/tgsi_core.h"

#if defined __GNUC__
#define ALIGNED_ATTRIBS 1
#else
#define ALIGNED_ATTRIBS 0
#endif

struct exec_machine {
   const struct setup_coefficient *coef; /**< will point to quad->coef */

#if ALIGNED_ATTRIBS
   GLfloat attr[FRAG_ATTRIB_MAX][NUM_CHANNELS][QUAD_SIZE] __attribute__(( aligned( 16 ) ));
#else
   GLfloat attr[FRAG_ATTRIB_MAX][NUM_CHANNELS][QUAD_SIZE];
#endif
};


/**
 * Compute quad's attributes values, as constants (GL_FLAT shading).
 */
static INLINE void cinterp( struct exec_machine *exec,
			    GLuint attrib,
			    GLuint i )
{
   GLuint j;

   for (j = 0; j < QUAD_SIZE; j++) {
      exec->attr[attrib][i][j] = exec->coef[attrib].a0[i];
   }
}


/**
 * Compute quad's attribute values by linear interpolation.
 *
 * Push into the fp:
 * 
 *   INPUT[attr] = MAD COEF_A0[attr], COEF_DADX[attr], INPUT_WPOS.xxxx
 *   INPUT[attr] = MAD INPUT[attr],   COEF_DADY[attr], INPUT_WPOS.yyyy
 */
static INLINE void linterp( struct exec_machine *exec,
			    GLuint attrib,
			    GLuint i )
{
   GLuint j;

   for (j = 0; j < QUAD_SIZE; j++) {
      const GLfloat x = exec->attr[FRAG_ATTRIB_WPOS][0][j];
      const GLfloat y = exec->attr[FRAG_ATTRIB_WPOS][1][j];
      exec->attr[attrib][i][j] = (exec->coef[attrib].a0[i] +
				  exec->coef[attrib].dadx[i] * x + 
				  exec->coef[attrib].dady[i] * y);
   }
}


/**
 * Compute quad's attribute values by linear interpolation with
 * perspective correction.
 *
 * Push into the fp:
 * 
 *   INPUT[attr] = MAD COEF_DADX[attr], INPUT_WPOS.xxxx, COEF_A0[attr]
 *   INPUT[attr] = MAD COEF_DADY[attr], INPUT_WPOS.yyyy, INPUT[attr]
 *   TMP         = RCP INPUT_WPOS.w
 *   INPUT[attr] = MUL INPUT[attr], TMP.xxxx
 *
 */
static INLINE void pinterp( struct exec_machine *exec,
			    GLuint attrib,
			    GLuint i )
{
   GLuint j;

   for (j = 0; j < QUAD_SIZE; j++) {
      const GLfloat x = exec->attr[FRAG_ATTRIB_WPOS][0][j];
      const GLfloat y = exec->attr[FRAG_ATTRIB_WPOS][1][j];
      /* FRAG_ATTRIB_WPOS.w here is really 1/w */
      const GLfloat w = 1.0 / exec->attr[FRAG_ATTRIB_WPOS][3][j];
      exec->attr[attrib][i][j] = ((exec->coef[attrib].a0[i] +
				   exec->coef[attrib].dadx[i] * x + 
				   exec->coef[attrib].dady[i] * y) * w);
   }
}



/* This should be done by the fragment shader execution unit (code
 * generated from the decl instructions).  Do it here for now.
 */
static void
shade_quad( struct quad_stage *qs, struct quad_header *quad )
{
   const struct softpipe_context *softpipe = qs->softpipe;
   struct exec_machine exec;
   const GLfloat fx = quad->x0;
   const GLfloat fy = quad->y0;
   GLuint attr, i;

   exec.coef = quad->coef;

   /* Position:
    */
   exec.attr[FRAG_ATTRIB_WPOS][0][0] = fx;
   exec.attr[FRAG_ATTRIB_WPOS][0][1] = fx + 1.0;
   exec.attr[FRAG_ATTRIB_WPOS][0][2] = fx;
   exec.attr[FRAG_ATTRIB_WPOS][0][3] = fx + 1.0;

   exec.attr[FRAG_ATTRIB_WPOS][1][0] = fy;
   exec.attr[FRAG_ATTRIB_WPOS][1][1] = fy;
   exec.attr[FRAG_ATTRIB_WPOS][1][2] = fy + 1.0;
   exec.attr[FRAG_ATTRIB_WPOS][1][3] = fy + 1.0;

   /* Z and W are done by linear interpolation */
   if (softpipe->need_z) {
      linterp(&exec, 0, 2);   /* attr[0].z */
   }

   if (softpipe->need_w) {
      linterp(&exec, 0, 3);  /* attr[0].w */
      /*invert(&exec, 0, 3);*/
   }

   /* Interpolate all the remaining attributes.  This will get pushed
    * into the fragment program's responsibilities at some point.
    * Start at 1 to skip fragment position attribute (computed above).
    */
   for (attr = 1; attr < quad->nr_attrs; attr++) {
      switch (softpipe->interp[attr]) {
      case INTERP_CONSTANT:
	 for (i = 0; i < NUM_CHANNELS; i++)
	    cinterp(&exec, attr, i);
	 break;

      case INTERP_LINEAR:
	 for (i = 0; i < NUM_CHANNELS; i++)
	    linterp(&exec, attr, i);
	 break;

      case INTERP_PERSPECTIVE:
	 for (i = 0; i < NUM_CHANNELS; i++)
	    pinterp(&exec, attr, i);
	 break;
      }
   }

#if 1
   /*softpipe->run_fs( tri->fp, quad, &tri->outputs );*/

   {
      struct tgsi_exec_machine machine;
      struct tgsi_exec_vector outputs[FRAG_ATTRIB_MAX + 1];
      struct tgsi_exec_vector *aoutputs;
      GLuint i;

#if !ALIGNED_ATTRIBS
      struct tgsi_exec_vector inputs[FRAG_ATTRIB_MAX + 1];
      struct tgsi_exec_vector *ainputs;
#endif

#ifdef DEBUG
      memset(&machine, 0, sizeof(machine));
#endif

      /* init machine state */
      tgsi_exec_machine_init(
         &machine,
         softpipe->fs.tokens );

      /* Consts does not require 16 byte alignment. */
      machine.Consts = softpipe->fs.constants->constant;

      aoutputs = (struct tgsi_exec_vector *) tgsi_align_128bit( outputs );
      machine.Outputs = aoutputs;

      assert( sizeof( struct tgsi_exec_vector ) == sizeof( exec.attr[0] ) );

#if ALIGNED_ATTRIBS
      machine.Inputs = (struct tgsi_exec_vector *) exec.attr;

      for (i = 0; i < softpipe->nr_attrs; i++) {
         /* Make sure fp_attr_to_slot[] is an identity transform. */
         assert( softpipe->fp_attr_to_slot[i] == i );
      }
#else
      ainputs = (struct tgsi_exec_vector *) tgsi_align_128bit( inputs );
      machine.Inputs = ainputs;

      /* load input registers */
      for (i = 0; i < softpipe->nr_attrs; i++) {
         /* Make sure fp_attr_to_slot[] is an identity transform. */
         assert( softpipe->fp_attr_to_slot[i] == i );

         memcpy(
            &ainputs[i],
            exec.attr[i],
            sizeof( ainputs[0] ) );
      }
#endif

      /* run shader */
      tgsi_exec_machine_run( &machine );

      /* store result color */
      memcpy(quad->outputs.color,
             &aoutputs[FRAG_ATTRIB_COL0].xyzw[0].f[0],
             sizeof(quad->outputs.color));
      if (softpipe->need_z) {
         /* XXX temporary */
         quad->outputs.depth[0] = exec.attr[0][2][0];
         quad->outputs.depth[1] = exec.attr[0][2][1];
         quad->outputs.depth[2] = exec.attr[0][2][2];
         quad->outputs.depth[3] = exec.attr[0][2][3];
      }
   }
#else
   {
      GLuint attr = softpipe->fp_attr_to_slot[FRAG_ATTRIB_COL0];
      assert(attr);

      memcpy(quad->outputs.color, 
	     exec.attr[attr], 
	     sizeof(quad->outputs.color));

      if (softpipe->need_z) {
         quad->outputs.depth[0] = exec.attr[0][2][0];
         quad->outputs.depth[1] = exec.attr[0][2][1];
         quad->outputs.depth[2] = exec.attr[0][2][2];
         quad->outputs.depth[3] = exec.attr[0][2][3];
      }
   }
#endif

   /* shader may cull fragments */
   if (quad->mask)
      qs->next->run(qs->next, quad);
}



struct quad_stage *sp_quad_shade_stage( struct softpipe_context *softpipe )
{
   struct quad_stage *stage = CALLOC_STRUCT(quad_stage);

   stage->softpipe = softpipe;
   stage->run = shade_quad;

   return stage;
}