brw_sf_emit.c

Mesa is an open-source implementation of the OpenGL specification - a system for rendering interacti

/*
 Copyright (C) Intel Corp.  2006.  All Rights Reserved.
 Intel funded Tungsten Graphics (http://www.tungstengraphics.com) to
 develop this 3D driver.
 
 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 COPYRIGHT OWNER(S) 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.
 
 **********************************************************************/
 /*
  * Authors:
  *   Keith Whitwell <[e-mail]>
  */
   

#include "glheader.h"
#include "macros.h"
#include "enums.h"

#include "intel_batchbuffer.h"

#include "brw_defines.h"
#include "brw_context.h"
#include "brw_eu.h"
#include "brw_util.h"
#include "brw_sf.h"


static struct brw_reg get_vert_attr(struct brw_sf_compile *c,
				    struct brw_reg vert,
				    GLuint attr)
{
   GLuint off = c->attr_to_idx[attr] / 2;
   GLuint sub = c->attr_to_idx[attr] % 2;

   return brw_vec4_grf(vert.nr + off, sub * 4);
}

static GLboolean have_attr(struct brw_sf_compile *c,
			   GLuint attr)
{
   return (c->key.attrs & (1<<attr)) ? 1 : 0;
}

/**
 * Sets VERT_RESULT_FOGC.Y  for gl_FrontFacing
 *
 * This is currently executed if the fragment program uses VERT_RESULT_FOGC
 * at all, but this could be eliminated with a scan of the FP contents.
 */
static void
do_front_facing( struct brw_sf_compile *c )
{
   struct brw_compile *p = &c->func; 
   int i;

   if (!have_attr(c, VERT_RESULT_FOGC))
      return;

   brw_push_insn_state(p);
   brw_CMP(p, brw_null_reg(), 
        c->key.frontface_ccw ? BRW_CONDITIONAL_G : BRW_CONDITIONAL_L,
        c->det, brw_imm_f(0));
   brw_set_predicate_control(p, BRW_PREDICATE_NONE);
   for (i = 0; i < 3; i++) {
       struct brw_reg fogc = get_vert_attr(c, c->vert[i],FRAG_ATTRIB_FOGC);
       brw_MOV(p, get_element(fogc, 1), brw_imm_f(0));
       brw_set_predicate_control(p, BRW_PREDICATE_NORMAL);
       brw_MOV(p, get_element(fogc, 1), brw_imm_f(1));
       brw_set_predicate_control(p, BRW_PREDICATE_NONE);
   }
   brw_pop_insn_state(p);
}

			 
/*********************************************************************** 
 * Twoside lighting
 */
static void copy_bfc( struct brw_sf_compile *c,
		      struct brw_reg vert )
{
   struct brw_compile *p = &c->func;
   GLuint i;

   for (i = 0; i < 2; i++) {
      if (have_attr(c, VERT_RESULT_COL0+i) &&
	  have_attr(c, VERT_RESULT_BFC0+i))
	 brw_MOV(p, 
		 get_vert_attr(c, vert, VERT_RESULT_COL0+i), 
		 get_vert_attr(c, vert, VERT_RESULT_BFC0+i));
   }
}


static void do_twoside_color( struct brw_sf_compile *c )
{
   struct brw_compile *p = &c->func;
   struct brw_instruction *if_insn;
   GLuint backface_conditional = c->key.frontface_ccw ? BRW_CONDITIONAL_G : BRW_CONDITIONAL_L;

   /* Already done in clip program:
    */
   if (c->key.primitive == SF_UNFILLED_TRIS)
      return;

   /* XXX: What happens if BFC isn't present?  This could only happen
    * for user-supplied vertex programs, as t_vp_build.c always does
    * the right thing.
    */
   if (!(have_attr(c, VERT_RESULT_COL0) && have_attr(c, VERT_RESULT_BFC0)) &&
       !(have_attr(c, VERT_RESULT_COL1) && have_attr(c, VERT_RESULT_BFC1)))
      return;
   
   /* Need to use BRW_EXECUTE_4 and also do an 4-wide compare in order
    * to get all channels active inside the IF.  In the clipping code
    * we run with NoMask, so it's not an option and we can use
    * BRW_EXECUTE_1 for all comparisions.
    */
   brw_push_insn_state(p);
   brw_CMP(p, vec4(brw_null_reg()), backface_conditional, c->det, brw_imm_f(0));
   if_insn = brw_IF(p, BRW_EXECUTE_4); 
   {
      switch (c->nr_verts) {
      case 3: copy_bfc(c, c->vert[2]);
      case 2: copy_bfc(c, c->vert[1]);
      case 1: copy_bfc(c, c->vert[0]);
      }
   }
   brw_ENDIF(p, if_insn);
   brw_pop_insn_state(p);
}



/***********************************************************************
 * Flat shading
 */

#define VERT_RESULT_COLOR_BITS ((1<<VERT_RESULT_COL0) | \
                                 (1<<VERT_RESULT_COL1))

static void copy_colors( struct brw_sf_compile *c,
		     struct brw_reg dst,
		     struct brw_reg src)
{
   struct brw_compile *p = &c->func;
   GLuint i;

   for (i = VERT_RESULT_COL0; i <= VERT_RESULT_COL1; i++) {
      if (have_attr(c,i))
	 brw_MOV(p, 
		 get_vert_attr(c, dst, i), 
		 get_vert_attr(c, src, i));
   }
}



/* Need to use a computed jump to copy flatshaded attributes as the
 * vertices are ordered according to y-coordinate before reaching this
 * point, so the PV could be anywhere.
 */
static void do_flatshade_triangle( struct brw_sf_compile *c )
{
   struct brw_compile *p = &c->func;
   struct brw_reg ip = brw_ip_reg();
   GLuint nr = brw_count_bits(c->key.attrs & VERT_RESULT_COLOR_BITS);
   if (!nr)
      return;

   /* Already done in clip program:
    */
   if (c->key.primitive == SF_UNFILLED_TRIS)
      return;

   brw_push_insn_state(p);
   
   brw_MUL(p, c->pv, c->pv, brw_imm_ud(nr*2+1));
   brw_JMPI(p, ip, ip, c->pv);

   copy_colors(c, c->vert[1], c->vert[0]);
   copy_colors(c, c->vert[2], c->vert[0]);
   brw_JMPI(p, ip, ip, brw_imm_ud(nr*4+1));

   copy_colors(c, c->vert[0], c->vert[1]);
   copy_colors(c, c->vert[2], c->vert[1]);
   brw_JMPI(p, ip, ip, brw_imm_ud(nr*2));

   copy_colors(c, c->vert[0], c->vert[2]);
   copy_colors(c, c->vert[1], c->vert[2]);

   brw_pop_insn_state(p);
}
	

static void do_flatshade_line( struct brw_sf_compile *c )
{
   struct brw_compile *p = &c->func;
   struct brw_reg ip = brw_ip_reg();
   GLuint nr = brw_count_bits(c->key.attrs & VERT_RESULT_COLOR_BITS);
   
   if (!nr)
      return;

   /* Already done in clip program: 
    */
   if (c->key.primitive == SF_UNFILLED_TRIS)
      return;

   brw_push_insn_state(p);
   
   brw_MUL(p, c->pv, c->pv, brw_imm_ud(nr+1));
   brw_JMPI(p, ip, ip, c->pv);
   copy_colors(c, c->vert[1], c->vert[0]);

   brw_JMPI(p, ip, ip, brw_imm_ud(nr));
   copy_colors(c, c->vert[0], c->vert[1]);

   brw_pop_insn_state(p);
}

	

/***********************************************************************
 * Triangle setup.
 */


static void alloc_regs( struct brw_sf_compile *c )
{
   GLuint reg, i;

   /* Values computed by fixed function unit:
    */
   c->pv  = retype(brw_vec1_grf(1, 1), BRW_REGISTER_TYPE_UD);
   c->det = brw_vec1_grf(1, 2);
   c->dx0 = brw_vec1_grf(1, 3);
   c->dx2 = brw_vec1_grf(1, 4);
   c->dy0 = brw_vec1_grf(1, 5);
   c->dy2 = brw_vec1_grf(1, 6);

   /* z and 1/w passed in seperately:
    */
   c->z[0]     = brw_vec1_grf(2, 0);
   c->inv_w[0] = brw_vec1_grf(2, 1);
   c->z[1]     = brw_vec1_grf(2, 2);
   c->inv_w[1] = brw_vec1_grf(2, 3);
   c->z[2]     = brw_vec1_grf(2, 4);
   c->inv_w[2] = brw_vec1_grf(2, 5);
   
   /* The vertices:
    */
   reg = 3;
   for (i = 0; i < c->nr_verts; i++) {
      c->vert[i] = brw_vec8_grf(reg, 0);
      reg += c->nr_attr_regs;
   }

   /* Temporaries, allocated after last vertex reg.
    */
   c->inv_det = brw_vec1_grf(reg, 0);  reg++;
   c->a1_sub_a0 = brw_vec8_grf(reg, 0);  reg++;
   c->a2_sub_a0 = brw_vec8_grf(reg, 0);  reg++;
   c->tmp = brw_vec8_grf(reg, 0);  reg++;

   /* Note grf allocation:
    */
   c->prog_data.total_grf = reg;
   

   /* Outputs of this program - interpolation coefficients for
    * rasterization:
    */
   c->m1Cx = brw_vec8_reg(BRW_MESSAGE_REGISTER_FILE, 1, 0);
   c->m2Cy = brw_vec8_reg(BRW_MESSAGE_REGISTER_FILE, 2, 0);
   c->m3C0 = brw_vec8_reg(BRW_MESSAGE_REGISTER_FILE, 3, 0);
}


static void copy_z_inv_w( struct brw_sf_compile *c )
{
   struct brw_compile *p = &c->func;
   GLuint i;

   brw_push_insn_state(p);
	
   /* Copy both scalars with a single MOV:
    */
   for (i = 0; i < c->nr_verts; i++)
      brw_MOV(p, vec2(suboffset(c->vert[i], 2)), vec2(c->z[i]));
	 
   brw_pop_insn_state(p);
}


static void invert_det( struct brw_sf_compile *c)
{
   /* Looks like we invert all 8 elements just to get 1/det in
    * position 2 !?!
    */
   brw_math(&c->func, 
	    c->inv_det, 
	    BRW_MATH_FUNCTION_INV,
	    BRW_MATH_SATURATE_NONE,
	    0, 
	    c->det,
	    BRW_MATH_DATA_SCALAR,
	    BRW_MATH_PRECISION_FULL);

}

#define NON_PERPECTIVE_ATTRS  (FRAG_BIT_WPOS | \
                               FRAG_BIT_COL0 | \
			       FRAG_BIT_COL1)

static GLboolean calculate_masks( struct brw_sf_compile *c,
				  GLuint reg,
				  GLushort *pc,
				  GLushort *pc_persp,
				  GLushort *pc_linear)
{
   GLboolean is_last_attr = (reg == c->nr_setup_regs - 1);
   GLuint persp_mask = c->key.attrs & ~NON_PERPECTIVE_ATTRS;
   GLuint linear_mask;

   if (c->key.do_flat_shading)
      linear_mask = c->key.attrs & ~(FRAG_BIT_COL0|FRAG_BIT_COL1);
   else
      linear_mask = c->key.attrs;

   *pc_persp = 0;
   *pc_linear = 0;
   *pc = 0xf;
      
   if (persp_mask & (1 << c->idx_to_attr[reg*2])) 
      *pc_persp = 0xf;

   if (linear_mask & (1 << c->idx_to_attr[reg*2])) 
      *pc_linear = 0xf;

   /* Maybe only processs one attribute on the final round:
    */
   if (reg*2+1 < c->nr_setup_attrs) {
      *pc |= 0xf0;

      if (persp_mask & (1 << c->idx_to_attr[reg*2+1])) 
	 *pc_persp |= 0xf0;

      if (linear_mask & (1 << c->idx_to_attr[reg*2+1])) 
	 *pc_linear |= 0xf0;
   }

   return is_last_attr;
}



void brw_emit_tri_setup( struct brw_sf_compile *c, GLboolean allocate)
{
   struct brw_compile *p = &c->func;
   GLuint i;

   c->nr_verts = 3;