sp_setup.c File Reference

Include dependency graph for sp_setup.c:

Go to the source code of this file.

Data Structures
struct	edge
	Triangle edge info. More...
struct	setup_context
	Triangle setup info (derived from draw_stage). More...
Defines
#define	DEBUG_VERTS   0
	Primitive rasterization/rendering (points, lines, triangles).
#define	DEBUG_FRAGS   0
#define	WAIT_FOR_COMPLETION(setup)   ((void) 0)
#define	CLIP_EMIT_QUAD(setup)   clip_emit_quad( setup, &setup->quad, 0 )
#define	EMIT_QUAD(setup, x, y, mask)
Functions
static boolean	is_inf_or_nan (float x)
	Test if x is NaN or +/- infinity.
static boolean	cull_tri (struct setup_context *setup, float det)
static void	quad_clip (struct setup_context *setup, struct quad_header *quad)
	Clip setup->quad against the scissor/surface bounds.
static void	clip_emit_quad (struct setup_context *setup, struct quad_header *quad, uint thread)
	Emit a quad (pass to next stage) with clipping.
static void	emit_quad (struct setup_context *setup, struct quad_header *quad, uint thread)
	Emit a quad (pass to next stage).
static int	block (int x)
	Given an X or Y coordinate, return the block/quad coordinate that it belongs to.
static void	flush_spans (struct setup_context *setup)
	Render a horizontal span of quads.
static boolean	setup_sort_vertices (struct setup_context *setup, float det, const float(*v0)[4], const float(*v1)[4], const float(*v2)[4])
	Returns: FALSE if coords are inf/nan (cull the tri), TRUE otherwise
static void	const_coeff (struct setup_context *setup, struct tgsi_interp_coef *coef, uint vertSlot, uint i)
	Compute a0 for a constant-valued coefficient (GL_FLAT shading).
static void	tri_linear_coeff (struct setup_context *setup, struct tgsi_interp_coef *coef, uint vertSlot, uint i)
	Compute a0, dadx and dady for a linearly interpolated coefficient, for a triangle.
static void	tri_persp_coeff (struct setup_context *setup, struct tgsi_interp_coef *coef, uint vertSlot, uint i)
	Compute a0, dadx and dady for a perspective-corrected interpolant, for a triangle.
static void	setup_fragcoord_coeff (struct setup_context *setup, uint slot)
	Special coefficient setup for gl_FragCoord.
static void	setup_tri_coefficients (struct setup_context *setup)
	Compute the setup->coef[] array dadx, dady, a0 values.
static void	setup_tri_edges (struct setup_context *setup)
static void	subtriangle (struct setup_context *setup, struct edge *eleft, struct edge *eright, unsigned lines)
	Render the upper or lower half of a triangle.
static float	calc_det (const float(*v0)[4], const float(*v1)[4], const float(*v2)[4])
	Recalculate prim's determinant.
void	setup_tri (struct setup_context *setup, const float(*v0)[4], const float(*v1)[4], const float(*v2)[4])
	Do setup for triangle rasterization, then render the triangle.
static void	line_linear_coeff (struct setup_context *setup, struct tgsi_interp_coef *coef, uint vertSlot, uint i)
	Compute a0, dadx and dady for a linearly interpolated coefficient, for a line.
static void	line_persp_coeff (struct setup_context *setup, struct tgsi_interp_coef *coef, uint vertSlot, uint i)
	Compute a0, dadx and dady for a perspective-corrected interpolant, for a line.
static boolean	setup_line_coefficients (struct setup_context *setup, const float(*v0)[4], const float(*v1)[4])
	Compute the setup->coef[] array dadx, dady, a0 values.
static void	plot (struct setup_context *setup, int x, int y)
	Plot a pixel in a line segment.
void	setup_line (struct setup_context *setup, const float(*v0)[4], const float(*v1)[4])
	Do setup for line rasterization, then render the line.
static void	point_persp_coeff (struct setup_context *setup, const float(*vert)[4], struct tgsi_interp_coef *coef, uint vertSlot, uint i)
void	setup_point (struct setup_context *setup, const float(*v0)[4])
	Do setup for point rasterization, then render the point.
void	setup_prepare (struct setup_context *setup)
void	setup_destroy_context (struct setup_context *setup)
struct setup_context *	setup_create_context (struct softpipe_context *softpipe)
	Create a new primitive setup/render stage.

---

Define Documentation

#define CLIP_EMIT_QUAD

(

setup

)

clip_emit_quad( setup, &setup->quad, 0 )

Definition at line 352 of file sp_setup.c.

#define DEBUG_FRAGS   0

Definition at line 52 of file sp_setup.c.

#define DEBUG_VERTS   0

Primitive rasterization/rendering (points, lines, triangles).

Author:

Keith Whitwell <keith@tungstengraphics.com>

Brian Paul

Definition at line 51 of file sp_setup.c.

#define EMIT_QUAD	(	setup,
		x,
		y,
		mask		)

Value:

do {\
      setup->quad.input.x0 = x;\
      setup->quad.input.y0 = y;\
      setup->quad.inout.mask = mask;\
      emit_quad( setup, &setup->quad, 0 );\
   } while (0)

Definition at line 407 of file sp_setup.c.

#define WAIT_FOR_COMPLETION

(

setup

)

((void) 0)

Definition at line 251 of file sp_setup.c.

---

Function Documentation

static int block

(

int

x

)

[static]

Given an X or Y coordinate, return the block/quad coordinate that it belongs to.

Definition at line 420 of file sp_setup.c.

{
   return x & ~1;

static float calc_det	(	const float *	v0[4],
		const float *	v1[4],
		const float *	v2[4]
	)			[static]

Recalculate prim's determinant.

This is needed as we don't have get this information through the vbuf_render interface & we must calculate it here.

Definition at line 917 of file sp_setup.c.

{
   /* edge vectors e = v0 - v2, f = v1 - v2 */
   const float ex = v0[0][0] - v2[0][0];
   const float ey = v0[0][1] - v2[0][1];
   const float fx = v1[0][0] - v2[0][0];
   const float fy = v1[0][1] - v2[0][1];

   /* det = cross(e,f).z */
   return ex * fy - ey * fx;

static void clip_emit_quad	(	struct setup_context *	setup,
		struct quad_header *	quad,
		uint	thread
	)			[static]

Emit a quad (pass to next stage) with clipping.

Definition at line 323 of file sp_setup.c.

References softpipe_context::first, quad_header::inout, quad_header_inout::mask, softpipe_context::quad, quad_clip(), quad_stage::run, and setup_context::softpipe.

{
   quad_clip( setup, quad );
   if (quad->inout.mask) {
      struct softpipe_context *sp = setup->softpipe;

      sp->quad[thread].first->run( sp->quad[thread].first, quad );
   }

static void const_coeff	(	struct setup_context *	setup,
		struct tgsi_interp_coef *	coef,
		uint	vertSlot,
		uint	i
	)			[static]

Compute a0 for a constant-valued coefficient (GL_FLAT shading).

The value value comes from vertex[slot][i]. The result will be put into setup->coef[slot].a0[i].

Parameters:

	slot	which attribute slot
	i	which component of the slot (0..3)

Definition at line 616 of file sp_setup.c.

{
   assert(i <= 3);

   coef->dadx[i] = 0;
   coef->dady[i] = 0;

   /* need provoking vertex info!
    */
   coef->a0[i] = setup->vprovoke[vertSlot][i];

static boolean cull_tri	(	struct setup_context *	setup,
		float	det
	)			[static]

Definition at line 267 of file sp_setup.c.

References FALSE, PIPE_WINDING_CCW, PIPE_WINDING_CW, TRUE, and setup_context::winding.

{
   if (det != 0) 
   {   
      /* if (det < 0 then Z points toward camera and triangle is 
       * counter-clockwise winding.
       */
      unsigned winding = (det < 0) ? PIPE_WINDING_CCW : PIPE_WINDING_CW;
      
      if ((winding & setup->winding) == 0) 
         return FALSE;
   }

   /* Culled:
    */
   return TRUE;

static void emit_quad	(	struct setup_context *	setup,
		struct quad_header *	quad,
		uint	thread
	)			[static]

Emit a quad (pass to next stage).

No clipping is done.

Definition at line 360 of file sp_setup.c.

References softpipe_context::first, quad_header::inout, quad_header_inout::mask, softpipe_context::quad, quad_stage::run, and setup_context::softpipe.

{
   struct softpipe_context *sp = setup->softpipe;
#if DEBUG_FRAGS
   uint mask = quad->inout.mask;
#endif

#if DEBUG_FRAGS
   if (mask & 1) setup->numFragsEmitted++;
   if (mask & 2) setup->numFragsEmitted++;
   if (mask & 4) setup->numFragsEmitted++;
   if (mask & 8) setup->numFragsEmitted++;
#endif
   sp->quad[thread].first->run( sp->quad[thread].first, quad );
#if DEBUG_FRAGS
   mask = quad->inout.mask;
   if (mask & 1) setup->numFragsWritten++;
   if (mask & 2) setup->numFragsWritten++;
   if (mask & 4) setup->numFragsWritten++;
   if (mask & 8) setup->numFragsWritten++;
#endif

static void flush_spans

(

struct setup_context *

setup

)

[static]

Render a horizontal span of quads.

Definition at line 429 of file sp_setup.c.

{
   const int xleft0 = setup->span.left[0];
   const int xleft1 = setup->span.left[1];
   const int xright0 = setup->span.right[0];
   const int xright1 = setup->span.right[1];
   int minleft, maxright;
   int x;

   switch (setup->span.y_flags) {
   case 0x3:
      /* both odd and even lines written (both quad rows) */
      minleft = block(MIN2(xleft0, xleft1));
      maxright = block(MAX2(xright0, xright1));
      for (x = minleft; x <= maxright; x += 2) {
         /* determine which of the four pixels is inside the span bounds */
         uint mask = 0x0;
         if (x >= xleft0 && x < xright0)
            mask |= MASK_TOP_LEFT;
         if (x >= xleft1 && x < xright1)
            mask |= MASK_BOTTOM_LEFT;
         if (x+1 >= xleft0 && x+1 < xright0)
            mask |= MASK_TOP_RIGHT;
         if (x+1 >= xleft1 && x+1 < xright1)
            mask |= MASK_BOTTOM_RIGHT;
         EMIT_QUAD( setup, x, setup->span.y, mask );
      }
      break;

   case 0x1:
      /* only even line written (quad top row) */
      minleft = block(xleft0);
      maxright = block(xright0);
      for (x = minleft; x <= maxright; x += 2) {
         uint mask = 0x0;
         if (x >= xleft0 && x < xright0)
            mask |= MASK_TOP_LEFT;
         if (x+1 >= xleft0 && x+1 < xright0)
            mask |= MASK_TOP_RIGHT;
         EMIT_QUAD( setup, x, setup->span.y, mask );
      }
      break;

   case 0x2:
      /* only odd line written (quad bottom row) */
      minleft = block(xleft1);
      maxright = block(xright1);
      for (x = minleft; x <= maxright; x += 2) {
         uint mask = 0x0;
         if (x >= xleft1 && x < xright1)
            mask |= MASK_BOTTOM_LEFT;
         if (x+1 >= xleft1 && x+1 < xright1)
            mask |= MASK_BOTTOM_RIGHT;
         EMIT_QUAD( setup, x, setup->span.y, mask );
      }
      break;

   default:
      return;
   }

   setup->span.y = 0;
   setup->span.y_flags = 0;
   setup->span.right[0] = 0;
   setup->span.right[1] = 0;

static boolean is_inf_or_nan

(

float

x

)

[static]

Test if x is NaN or +/- infinity.

Definition at line 259 of file sp_setup.c.

References fi::f, and fi::i.

{
   union fi tmp;
   tmp.f = x;
   return !(int)((unsigned int)((tmp.i & 0x7fffffff)-0x7f800000) >> 31);

static void line_linear_coeff	(	struct setup_context *	setup,
		struct tgsi_interp_coef *	coef,
		uint	vertSlot,
		uint	i
	)			[static]

Compute a0, dadx and dady for a linearly interpolated coefficient, for a line.

Definition at line 1011 of file sp_setup.c.

References tgsi_interp_coef::a0, tgsi_interp_coef::dadx, tgsi_interp_coef::dady, edge::dx, edge::dy, setup_context::emaj, setup_context::oneoverarea, setup_context::vmax, and setup_context::vmin.

{
   const float da = setup->vmax[vertSlot][i] - setup->vmin[vertSlot][i];
   const float dadx = da * setup->emaj.dx * setup->oneoverarea;
   const float dady = da * setup->emaj.dy * setup->oneoverarea;
   coef->dadx[i] = dadx;
   coef->dady[i] = dady;
   coef->a0[i] = (setup->vmin[vertSlot][i] -
                  (dadx * (setup->vmin[0][0] - 0.5f) +
                   dady * (setup->vmin[0][1] - 0.5f)));

static void line_persp_coeff	(	struct setup_context *	setup,
		struct tgsi_interp_coef *	coef,
		uint	vertSlot,
		uint	i
	)			[static]

Compute a0, dadx and dady for a perspective-corrected interpolant, for a line.

Definition at line 1031 of file sp_setup.c.

References tgsi_interp_coef::a0, tgsi_interp_coef::dadx, tgsi_interp_coef::dady, edge::dx, edge::dy, setup_context::emaj, setup_context::oneoverarea, setup_context::vmax, and setup_context::vmin.

{
   /* XXX double-check/verify this arithmetic */
   const float a0 = setup->vmin[vertSlot][i] * setup->vmin[0][3];
   const float a1 = setup->vmax[vertSlot][i] * setup->vmax[0][3];
   const float da = a1 - a0;
   const float dadx = da * setup->emaj.dx * setup->oneoverarea;
   const float dady = da * setup->emaj.dy * setup->oneoverarea;
   coef->dadx[i] = dadx;
   coef->dady[i] = dady;
   coef->a0[i] = (setup->vmin[vertSlot][i] -
                  (dadx * (setup->vmin[0][0] - 0.5f) +
                   dady * (setup->vmin[0][1] - 0.5f)));

static void plot	(	struct setup_context *	setup,
		int	x,
		int	y
	)			[static]

Plot a pixel in a line segment.

Definition at line 1124 of file sp_setup.c.

References CLIP_EMIT_QUAD, quad_header::inout, quad_header::input, quad_header_inout::mask, setup_context::quad, quad_header_input::x0, and quad_header_input::y0.

{
   const int iy = y & 1;
   const int ix = x & 1;
   const int quadX = x - ix;
   const int quadY = y - iy;
   const int mask = (1 << ix) << (2 * iy);

   if (quadX != setup->quad.input.x0 ||
       quadY != setup->quad.input.y0)
   {
      /* flush prev quad, start new quad */

      if (setup->quad.input.x0 != -1)
         CLIP_EMIT_QUAD(setup);

      setup->quad.input.x0 = quadX;
      setup->quad.input.y0 = quadY;
      setup->quad.inout.mask = 0x0;
   }

   setup->quad.inout.mask |= mask;

static void point_persp_coeff	(	struct setup_context *	setup,
		const float *	vert[4],
		struct tgsi_interp_coef *	coef,
		uint	vertSlot,
		uint	i
	)			[static]

Definition at line 1268 of file sp_setup.c.

References tgsi_interp_coef::a0, assert, tgsi_interp_coef::dadx, and tgsi_interp_coef::dady.

{
   assert(i <= 3);
   coef->dadx[i] = 0.0F;
   coef->dady[i] = 0.0F;
   coef->a0[i] = vert[vertSlot][i] * vert[0][3];

static void quad_clip	(	struct setup_context *	setup,
		struct quad_header *	quad
	)			[static]

Clip setup->quad against the scissor/surface bounds.

Definition at line 292 of file sp_setup.c.

References softpipe_context::cliprect, quad_header::inout, quad_header::input, quad_header_inout::mask, MASK_BOTTOM_LEFT, MASK_BOTTOM_RIGHT, MASK_TOP_LEFT, MASK_TOP_RIGHT, pipe_scissor_state::maxx, pipe_scissor_state::maxy, pipe_scissor_state::minx, pipe_scissor_state::miny, setup_context::softpipe, quad_header_input::x0, and quad_header_input::y0.

{
   const struct pipe_scissor_state *cliprect = &setup->softpipe->cliprect;
   const int minx = (int) cliprect->minx;
   const int maxx = (int) cliprect->maxx;
   const int miny = (int) cliprect->miny;
   const int maxy = (int) cliprect->maxy;

   if (quad->input.x0 >= maxx ||
       quad->input.y0 >= maxy ||
       quad->input.x0 + 1 < minx ||
       quad->input.y0 + 1 < miny) {
      /* totally clipped */
      quad->inout.mask = 0x0;
      return;
   }
   if (quad->input.x0 < minx)
      quad->inout.mask &= (MASK_BOTTOM_RIGHT | MASK_TOP_RIGHT);
   if (quad->input.y0 < miny)
      quad->inout.mask &= (MASK_BOTTOM_LEFT | MASK_BOTTOM_RIGHT);
   if (quad->input.x0 == maxx - 1)
      quad->inout.mask &= (MASK_BOTTOM_LEFT | MASK_TOP_LEFT);
   if (quad->input.y0 == maxy - 1)
      quad->inout.mask &= (MASK_TOP_LEFT | MASK_TOP_RIGHT);

struct setup_context* setup_create_context

(

struct softpipe_context *

softpipe

)

[read]

Create a new primitive setup/render stage.

Definition at line 1538 of file sp_setup.c.

{
   struct setup_context *setup = CALLOC_STRUCT(setup_context);
#if SP_NUM_QUAD_THREADS > 1
   uint i;
#endif

   setup->softpipe = softpipe;

   setup->quad.coef = setup->coef;
   setup->quad.posCoef = &setup->posCoef;

#if SP_NUM_QUAD_THREADS > 1
   setup->que.first = 0;
   setup->que.last = 0;
   pipe_mutex_init( setup->que.que_mutex );
   pipe_condvar_init( setup->que.que_notfull_condvar );
   pipe_condvar_init( setup->que.que_notempty_condvar );
   setup->que.jobs_added = 0;
   setup->que.jobs_done = 0;
   pipe_condvar_init( setup->que.que_done_condvar );
   for (i = 0; i < SP_NUM_QUAD_THREADS; i++) {
      setup->threads[i].setup = setup;
      setup->threads[i].id = i;
      setup->threads[i].handle = pipe_thread_create( quad_thread, &setup->threads[i] );
   }
#endif

   return setup;

void setup_destroy_context

(

struct setup_context *

setup

)

Definition at line 1529 of file sp_setup.c.

References FREE.

{
   FREE( setup );

static void setup_fragcoord_coeff	(	struct setup_context *	setup,
		uint	slot
	)			[static]

Special coefficient setup for gl_FragCoord.

X and Y are trivial, though Y has to be inverted for OpenGL. Z and W are copied from posCoef which should have already been computed. We could do a bit less work if we'd examine gl_FragCoord's swizzle mask.

Definition at line 725 of file sp_setup.c.

References tgsi_interp_coef::a0, setup_context::coef, tgsi_interp_coef::dadx, tgsi_interp_coef::dady, softpipe_context::framebuffer, pipe_framebuffer_state::height, pipe_rasterizer_state::origin_lower_left, setup_context::posCoef, softpipe_context::rasterizer, and setup_context::softpipe.

{
   /*X*/
   setup->coef[slot].a0[0] = 0;
   setup->coef[slot].dadx[0] = 1.0;
   setup->coef[slot].dady[0] = 0.0;
   /*Y*/
   if (setup->softpipe->rasterizer->origin_lower_left) {
      /* y=0=bottom */
      const int winHeight = setup->softpipe->framebuffer.height;
      setup->coef[slot].a0[1] = (float) (winHeight - 1);
      setup->coef[slot].dady[1] = -1.0;
   }
   else {
      /* y=0=top */
      setup->coef[slot].a0[1] = 0.0;
      setup->coef[slot].dady[1] = 1.0;
   }
   setup->coef[slot].dadx[1] = 0.0;
   /*Z*/
   setup->coef[slot].a0[2] = setup->posCoef.a0[2];
   setup->coef[slot].dadx[2] = setup->posCoef.dadx[2];
   setup->coef[slot].dady[2] = setup->posCoef.dady[2];
   /*W*/
   setup->coef[slot].a0[3] = setup->posCoef.a0[3];
   setup->coef[slot].dadx[3] = setup->posCoef.dadx[3];
   setup->coef[slot].dady[3] = setup->posCoef.dady[3];

void setup_line	(	struct setup_context *	setup,
		const float *	v0[4],
		const float *	v1[4]
	)

Do setup for line rasterization, then render the line.

Single-pixel width, no stipple, etc. We rely on the 'draw' module to handle stippling and wide lines.

Definition at line 1155 of file sp_setup.c.

References assert, CLIP_EMIT_QUAD, quad_header_input::coverage, debug_printf(), quad_header::inout, quad_header::input, quad_header_inout::mask, softpipe_context::no_rast, plot(), quad_header_input::prim, PRIM_LINE, setup_context::quad, setup_line_coefficients(), setup_context::softpipe, WAIT_FOR_COMPLETION, quad_header_input::x0, and quad_header_input::y0.

{
   int x0 = (int) v0[0][0];
   int x1 = (int) v1[0][0];
   int y0 = (int) v0[0][1];
   int y1 = (int) v1[0][1];
   int dx = x1 - x0;
   int dy = y1 - y0;
   int xstep, ystep;

#if DEBUG_VERTS
   debug_printf("Setup line:\n");
   print_vertex(setup, v0);
   print_vertex(setup, v1);
#endif

   if (setup->softpipe->no_rast)
      return;

   if (dx == 0 && dy == 0)
      return;

   if (!setup_line_coefficients(setup, v0, v1))
      return;

   assert(v0[0][0] < 1.0e9);
   assert(v0[0][1] < 1.0e9);
   assert(v1[0][0] < 1.0e9);
   assert(v1[0][1] < 1.0e9);

   if (dx < 0) {
      dx = -dx;   /* make positive */
      xstep = -1;
   }
   else {
      xstep = 1;
   }

   if (dy < 0) {
      dy = -dy;   /* make positive */
      ystep = -1;
   }
   else {
      ystep = 1;
   }

   assert(dx >= 0);
   assert(dy >= 0);

   setup->quad.input.x0 = setup->quad.input.y0 = -1;
   setup->quad.inout.mask = 0x0;
   setup->quad.input.prim = PRIM_LINE;
   /* XXX temporary: set coverage to 1.0 so the line appears
    * if AA mode happens to be enabled.
    */
   setup->quad.input.coverage[0] =
   setup->quad.input.coverage[1] =
   setup->quad.input.coverage[2] =
   setup->quad.input.coverage[3] = 1.0;

   if (dx > dy) {
      /*** X-major line ***/
      int i;
      const int errorInc = dy + dy;
      int error = errorInc - dx;
      const int errorDec = error - dx;

      for (i = 0; i < dx; i++) {
         plot(setup, x0, y0);

         x0 += xstep;
         if (error < 0) {
            error += errorInc;
         }
         else {
            error += errorDec;
            y0 += ystep;
         }
      }
   }
   else {
      /*** Y-major line ***/
      int i;
      const int errorInc = dx + dx;
      int error = errorInc - dy;
      const int errorDec = error - dy;

      for (i = 0; i < dy; i++) {
         plot(setup, x0, y0);

         y0 += ystep;
         if (error < 0) {
            error += errorInc;
         }
         else {
            error += errorDec;
            x0 += xstep;
         }
      }
   }

   /* draw final quad */
   if (setup->quad.inout.mask) {
      CLIP_EMIT_QUAD(setup);
   }

   WAIT_FOR_COMPLETION(setup);

static boolean setup_line_coefficients	(	struct setup_context *	setup,
		const float *	v0[4],
		const float *	v1[4]
	)			[static]

Compute the setup->coef[] array dadx, dady, a0 values.

Must be called after setup->vmin,vmax are initialized.

Definition at line 1054 of file sp_setup.c.

References tgsi_interp_coef::a0, assert, vertex_info::attrib, setup_context::coef, const_coeff(), tgsi_interp_coef::dadx, tgsi_interp_coef::dady, edge::dx, edge::dy, setup_context::emaj, quad_header_input::facing, FALSE, softpipe_context::fs, sp_fragment_shader::info, quad_header::input, tgsi_shader_info::input_semantic_name, INTERP_CONSTANT, INTERP_LINEAR, vertex_info::interp_mode, INTERP_PERSPECTIVE, INTERP_POS, is_inf_or_nan(), line_linear_coeff(), line_persp_coeff(), tgsi_shader_info::num_inputs, setup_context::oneoverarea, setup_context::posCoef, setup_context::quad, setup_fragcoord_coeff(), setup_context::softpipe, softpipe_get_vertex_info(), vertex_info::src_index, TGSI_SEMANTIC_FOG, TRUE, setup_context::vmax, setup_context::vmin, and setup_context::vprovoke.

{
   struct softpipe_context *softpipe = setup->softpipe;
   const struct sp_fragment_shader *spfs = softpipe->fs;
   const struct vertex_info *vinfo = softpipe_get_vertex_info(softpipe);
   uint fragSlot;
   float area;

   /* use setup->vmin, vmax to point to vertices */
   setup->vprovoke = v1;
   setup->vmin = v0;
   setup->vmax = v1;

   setup->emaj.dx = setup->vmax[0][0] - setup->vmin[0][0];
   setup->emaj.dy = setup->vmax[0][1] - setup->vmin[0][1];

   /* NOTE: this is not really area but something proportional to it */
   area = setup->emaj.dx * setup->emaj.dx + setup->emaj.dy * setup->emaj.dy;
   if (area == 0.0f || is_inf_or_nan(area))
      return FALSE;
   setup->oneoverarea = 1.0f / area;

   /* z and w are done by linear interpolation:
    */
   line_linear_coeff(setup, &setup->posCoef, 0, 2);
   line_linear_coeff(setup, &setup->posCoef, 0, 3);

   /* setup interpolation for all the remaining attributes:
    */
   for (fragSlot = 0; fragSlot < spfs->info.num_inputs; fragSlot++) {
      const uint vertSlot = vinfo->attrib[fragSlot].src_index;
      uint j;

      switch (vinfo->attrib[fragSlot].interp_mode) {
      case INTERP_CONSTANT:
         for (j = 0; j < NUM_CHANNELS; j++)
            const_coeff(setup, &setup->coef[fragSlot], vertSlot, j);
         break;
      case INTERP_LINEAR:
         for (j = 0; j < NUM_CHANNELS; j++)
            line_linear_coeff(setup, &setup->coef[fragSlot], vertSlot, j);
         break;
      case INTERP_PERSPECTIVE:
         for (j = 0; j < NUM_CHANNELS; j++)
            line_persp_coeff(setup, &setup->coef[fragSlot], vertSlot, j);
         break;
      case INTERP_POS:
         setup_fragcoord_coeff(setup, fragSlot);
         break;
      default:
         assert(0);
      }

      if (spfs->info.input_semantic_name[fragSlot] == TGSI_SEMANTIC_FOG) {
         /* FOG.y = front/back facing  XXX fix this */
         setup->coef[fragSlot].a0[1] = 1.0f - setup->quad.input.facing;
         setup->coef[fragSlot].dadx[1] = 0.0;
         setup->coef[fragSlot].dady[1] = 0.0;
      }
   }
   return TRUE;

void setup_point	(	struct setup_context *	setup,
		const float *	v0[4]
	)

Do setup for point rasterization, then render the point.

Round or square points... XXX could optimize a lot for 1-pixel points.

Definition at line 1286 of file sp_setup.c.

References tgsi_interp_coef::a0, assert, vertex_info::attrib, block(), CLIP_EMIT_QUAD, setup_context::coef, const_coeff(), quad_header_input::coverage, tgsi_interp_coef::dadx, tgsi_interp_coef::dady, debug_printf(), quad_header_input::facing, softpipe_context::fs, sp_fragment_shader::info, quad_header::inout, quad_header::input, tgsi_shader_info::input_semantic_name, INTERP_CONSTANT, INTERP_LINEAR, vertex_info::interp_mode, INTERP_PERSPECTIVE, INTERP_POS, quad_header_inout::mask, MASK_BOTTOM_LEFT, MASK_BOTTOM_RIGHT, MASK_TOP_LEFT, MASK_TOP_RIGHT, MAX2, MIN2, softpipe_context::no_rast, tgsi_shader_info::num_inputs, point_persp_coeff(), pipe_rasterizer_state::point_size, pipe_rasterizer_state::point_smooth, setup_context::posCoef, quad_header_input::prim, PRIM_POINT, softpipe_context::psize_slot, setup_context::quad, QUAD_BOTTOM_LEFT, QUAD_BOTTOM_RIGHT, QUAD_TOP_LEFT, QUAD_TOP_RIGHT, softpipe_context::rasterizer, setup_fragcoord_coeff(), setup_context::softpipe, softpipe_get_vertex_info(), vertex_info::src_index, TGSI_SEMANTIC_FOG, setup_context::vprovoke, WAIT_FOR_COMPLETION, quad_header_input::x0, and quad_header_input::y0.

{
   struct softpipe_context *softpipe = setup->softpipe;
   const struct sp_fragment_shader *spfs = softpipe->fs;
   const int sizeAttr = setup->softpipe->psize_slot;
   const float size
      = sizeAttr > 0 ? v0[sizeAttr][0]
      : setup->softpipe->rasterizer->point_size;
   const float halfSize = 0.5F * size;
   const boolean round = (boolean) setup->softpipe->rasterizer->point_smooth;
   const float x = v0[0][0];  /* Note: data[0] is always position */
   const float y = v0[0][1];
   const struct vertex_info *vinfo = softpipe_get_vertex_info(softpipe);
   uint fragSlot;

#if DEBUG_VERTS
   debug_printf("Setup point:\n");
   print_vertex(setup, v0);
#endif

   if (softpipe->no_rast)
      return;

   /* For points, all interpolants are constant-valued.
    * However, for point sprites, we'll need to setup texcoords appropriately.
    * XXX: which coefficients are the texcoords???
    * We may do point sprites as textured quads...
    *
    * KW: We don't know which coefficients are texcoords - ultimately
    * the choice of what interpolation mode to use for each attribute
    * should be determined by the fragment program, using
    * per-attribute declaration statements that include interpolation
    * mode as a parameter.  So either the fragment program will have
    * to be adjusted for pointsprite vs normal point behaviour, or
    * otherwise a special interpolation mode will have to be defined
    * which matches the required behaviour for point sprites.  But -
    * the latter is not a feature of normal hardware, and as such
    * probably should be ruled out on that basis.
    */
   setup->vprovoke = v0;

   /* setup Z, W */
   const_coeff(setup, &setup->posCoef, 0, 2);
   const_coeff(setup, &setup->posCoef, 0, 3);

   for (fragSlot = 0; fragSlot < spfs->info.num_inputs; fragSlot++) {
      const uint vertSlot = vinfo->attrib[fragSlot].src_index;
      uint j;

      switch (vinfo->attrib[fragSlot].interp_mode) {
      case INTERP_CONSTANT:
         /* fall-through */
      case INTERP_LINEAR:
         for (j = 0; j < NUM_CHANNELS; j++)
            const_coeff(setup, &setup->coef[fragSlot], vertSlot, j);
         break;
      case INTERP_PERSPECTIVE:
         for (j = 0; j < NUM_CHANNELS; j++)
            point_persp_coeff(setup, setup->vprovoke,
                              &setup->coef[fragSlot], vertSlot, j);
         break;
      case INTERP_POS:
         setup_fragcoord_coeff(setup, fragSlot);
         break;
      default:
         assert(0);
      }

      if (spfs->info.input_semantic_name[fragSlot] == TGSI_SEMANTIC_FOG) {
         /* FOG.y = front/back facing  XXX fix this */
         setup->coef[fragSlot].a0[1] = 1.0f - setup->quad.input.facing;
         setup->coef[fragSlot].dadx[1] = 0.0;
         setup->coef[fragSlot].dady[1] = 0.0;
      }
   }

   setup->quad.input.prim = PRIM_POINT;

   if (halfSize <= 0.5 && !round) {
      /* special case for 1-pixel points */
      const int ix = ((int) x) & 1;
      const int iy = ((int) y) & 1;
      setup->quad.input.x0 = (int) x - ix;
      setup->quad.input.y0 = (int) y - iy;
      setup->quad.inout.mask = (1 << ix) << (2 * iy);
      CLIP_EMIT_QUAD(setup);
   }
   else {
      if (round) {
         /* rounded points */
         const int ixmin = block((int) (x - halfSize));
         const int ixmax = block((int) (x + halfSize));
         const int iymin = block((int) (y - halfSize));
         const int iymax = block((int) (y + halfSize));
         const float rmin = halfSize - 0.7071F;  /* 0.7071 = sqrt(2)/2 */
         const float rmax = halfSize + 0.7071F;
         const float rmin2 = MAX2(0.0F, rmin * rmin);
         const float rmax2 = rmax * rmax;
         const float cscale = 1.0F / (rmax2 - rmin2);
         int ix, iy;

         for (iy = iymin; iy <= iymax; iy += 2) {
            for (ix = ixmin; ix <= ixmax; ix += 2) {
               float dx, dy, dist2, cover;

               setup->quad.inout.mask = 0x0;

               dx = (ix + 0.5f) - x;
               dy = (iy + 0.5f) - y;
               dist2 = dx * dx + dy * dy;
               if (dist2 <= rmax2) {
                  cover = 1.0F - (dist2 - rmin2) * cscale;
                  setup->quad.input.coverage[QUAD_TOP_LEFT] = MIN2(cover, 1.0f);
                  setup->quad.inout.mask |= MASK_TOP_LEFT;
               }

               dx = (ix + 1.5f) - x;
               dy = (iy + 0.5f) - y;
               dist2 = dx * dx + dy * dy;
               if (dist2 <= rmax2) {
                  cover = 1.0F - (dist2 - rmin2) * cscale;
                  setup->quad.input.coverage[QUAD_TOP_RIGHT] = MIN2(cover, 1.0f);
                  setup->quad.inout.mask |= MASK_TOP_RIGHT;
               }

               dx = (ix + 0.5f) - x;
               dy = (iy + 1.5f) - y;
               dist2 = dx * dx + dy * dy;
               if (dist2 <= rmax2) {
                  cover = 1.0F - (dist2 - rmin2) * cscale;
                  setup->quad.input.coverage[QUAD_BOTTOM_LEFT] = MIN2(cover, 1.0f);
                  setup->quad.inout.mask |= MASK_BOTTOM_LEFT;
               }

               dx = (ix + 1.5f) - x;
               dy = (iy + 1.5f) - y;
               dist2 = dx * dx + dy * dy;
               if (dist2 <= rmax2) {
                  cover = 1.0F - (dist2 - rmin2) * cscale;
                  setup->quad.input.coverage[QUAD_BOTTOM_RIGHT] = MIN2(cover, 1.0f);
                  setup->quad.inout.mask |= MASK_BOTTOM_RIGHT;
               }

               if (setup->quad.inout.mask) {
                  setup->quad.input.x0 = ix;
                  setup->quad.input.y0 = iy;
                  CLIP_EMIT_QUAD(setup);
               }
            }
         }
      }
      else {
         /* square points */
         const int xmin = (int) (x + 0.75 - halfSize);
         const int ymin = (int) (y + 0.25 - halfSize);
         const int xmax = xmin + (int) size;
         const int ymax = ymin + (int) size;
         /* XXX could apply scissor to xmin,ymin,xmax,ymax now */
         const int ixmin = block(xmin);
         const int ixmax = block(xmax - 1);
         const int iymin = block(ymin);
         const int iymax = block(ymax - 1);
         int ix, iy;

         /*
         debug_printf("(%f, %f) -> X:%d..%d Y:%d..%d\n", x, y, xmin, xmax,ymin,ymax);
         */
         for (iy = iymin; iy <= iymax; iy += 2) {
            uint rowMask = 0xf;
            if (iy < ymin) {
               /* above the top edge */
               rowMask &= (MASK_BOTTOM_LEFT | MASK_BOTTOM_RIGHT);
            }
            if (iy + 1 >= ymax) {
               /* below the bottom edge */
               rowMask &= (MASK_TOP_LEFT | MASK_TOP_RIGHT);
            }

            for (ix = ixmin; ix <= ixmax; ix += 2) {
               uint mask = rowMask;

               if (ix < xmin) {
                  /* fragment is past left edge of point, turn off left bits */
                  mask &= (MASK_BOTTOM_RIGHT | MASK_TOP_RIGHT);
               }
               if (ix + 1 >= xmax) {
                  /* past the right edge */
                  mask &= (MASK_BOTTOM_LEFT | MASK_TOP_LEFT);
               }

               setup->quad.inout.mask = mask;
               setup->quad.input.x0 = ix;
               setup->quad.input.y0 = iy;
               CLIP_EMIT_QUAD(setup);
            }
         }
      }
   }

   WAIT_FOR_COMPLETION(setup);

void setup_prepare

(

struct setup_context *

setup

)

Definition at line 1489 of file sp_setup.c.

References quad_stage::begin, pipe_framebuffer_state::cbufs, pipe_rasterizer_state::cull_mode, softpipe_context::dirty, softpipe_context::draw, draw_num_vs_outputs(), pipe_rasterizer_state::fill_ccw, pipe_rasterizer_state::fill_cw, softpipe_context::first, softpipe_context::framebuffer, quad_header::nr_attrs, pipe_framebuffer_state::num_cbufs, PIPE_POLYGON_MODE_FILL, PIPE_PRIM_TRIANGLES, PIPE_SURFACE_STATUS_DEFINED, PIPE_WINDING_NONE, softpipe_context::quad, setup_context::quad, softpipe_context::rasterizer, softpipe_context::reduced_api_prim, setup_context::softpipe, softpipe_update_derived(), SP_NUM_QUAD_THREADS, pipe_surface::status, setup_context::winding, and pipe_framebuffer_state::zsbuf.

{
   struct softpipe_context *sp = setup->softpipe;
   unsigned i;

   if (sp->dirty) {
      softpipe_update_derived(sp);
   }

   /* Mark surfaces as defined now */
   for (i = 0; i < sp->framebuffer.num_cbufs; i++){
      if (sp->framebuffer.cbufs[i]) {
         sp->framebuffer.cbufs[i]->status = PIPE_SURFACE_STATUS_DEFINED;
      }
   }
   if (sp->framebuffer.zsbuf) {
      sp->framebuffer.zsbuf->status = PIPE_SURFACE_STATUS_DEFINED;
   }

   /* Note: nr_attrs is only used for debugging (vertex printing) */
   setup->quad.nr_attrs = draw_num_vs_outputs(sp->draw);

   for (i = 0; i < SP_NUM_QUAD_THREADS; i++) {
      sp->quad[i].first->begin( sp->quad[i].first );
   }

   if (sp->reduced_api_prim == PIPE_PRIM_TRIANGLES &&
       sp->rasterizer->fill_cw == PIPE_POLYGON_MODE_FILL &&
       sp->rasterizer->fill_ccw == PIPE_POLYGON_MODE_FILL) {
      /* we'll do culling */
      setup->winding = sp->rasterizer->cull_mode;
   }
   else {
      /* 'draw' will do culling */
      setup->winding = PIPE_WINDING_NONE;
   }

static boolean setup_sort_vertices	(	struct setup_context *	setup,
		float	det,
		const float *	v0[4],
		const float *	v1[4],
		const float *	v2[4]
	)			[static]

Returns:

FALSE if coords are inf/nan (cull the tri), TRUE otherwise

Definition at line 513 of file sp_setup.c.

{
   setup->vprovoke = v2;

   /* determine bottom to top order of vertices */
   {
      float y0 = v0[0][1];
      float y1 = v1[0][1];
      float y2 = v2[0][1];
      if (y0 <= y1) {
         if (y1 <= y2) {
            /* y0<=y1<=y2 */
            setup->vmin = v0;
            setup->vmid = v1;
            setup->vmax = v2;
         }
         else if (y2 <= y0) {
            /* y2<=y0<=y1 */
            setup->vmin = v2;
            setup->vmid = v0;
            setup->vmax = v1;
         }
         else {
            /* y0<=y2<=y1 */
            setup->vmin = v0;
            setup->vmid = v2;
            setup->vmax = v1;
         }
      }
      else {
         if (y0 <= y2) {
            /* y1<=y0<=y2 */
            setup->vmin = v1;
            setup->vmid = v0;
            setup->vmax = v2;
         }
         else if (y2 <= y1) {
            /* y2<=y1<=y0 */
            setup->vmin = v2;
            setup->vmid = v1;
            setup->vmax = v0;
         }
         else {
            /* y1<=y2<=y0 */
            setup->vmin = v1;
            setup->vmid = v2;
            setup->vmax = v0;
         }
      }
   }

   setup->ebot.dx = setup->vmid[0][0] - setup->vmin[0][0];
   setup->ebot.dy = setup->vmid[0][1] - setup->vmin[0][1];
   setup->emaj.dx = setup->vmax[0][0] - setup->vmin[0][0];
   setup->emaj.dy = setup->vmax[0][1] - setup->vmin[0][1];
   setup->etop.dx = setup->vmax[0][0] - setup->vmid[0][0];
   setup->etop.dy = setup->vmax[0][1] - setup->vmid[0][1];

   /*
    * Compute triangle's area.  Use 1/area to compute partial
    * derivatives of attributes later.
    *
    * The area will be the same as prim->det, but the sign may be
    * different depending on how the vertices get sorted above.
    *
    * To determine whether the primitive is front or back facing we
    * use the prim->det value because its sign is correct.
    */
   {
      const float area = (setup->emaj.dx * setup->ebot.dy -
                            setup->ebot.dx * setup->emaj.dy);

      setup->oneoverarea = 1.0f / area;

      /*
      debug_printf("%s one-over-area %f  area %f  det %f\n",
                   __FUNCTION__, setup->oneoverarea, area, det );
      */
      if (is_inf_or_nan(setup->oneoverarea))
         return FALSE;
   }

   /* We need to know if this is a front or back-facing triangle for:
    *  - the GLSL gl_FrontFacing fragment attribute (bool)
    *  - two-sided stencil test
    */
   setup->quad.input.facing = (det > 0.0) ^ (setup->softpipe->rasterizer->front_winding == PIPE_WINDING_CW);

   return TRUE;

void setup_tri	(	struct setup_context *	setup,
		const float *	v0[4],
		const float *	v1[4],
		const float *	v2[4]
	)

Do setup for triangle rasterization, then render the triangle.

Definition at line 935 of file sp_setup.c.

{
   float det;

#if DEBUG_VERTS
   debug_printf("Setup triangle:\n");
   print_vertex(setup, v0);
   print_vertex(setup, v1);
   print_vertex(setup, v2);
#endif

   if (setup->softpipe->no_rast)
      return;
   
   det = calc_det(v0, v1, v2);
   /*
   debug_printf("%s\n", __FUNCTION__ );
   */

#if DEBUG_FRAGS
   setup->numFragsEmitted = 0;
   setup->numFragsWritten = 0;
#endif

   if (cull_tri( setup, det ))
      return;

   if (!setup_sort_vertices( setup, det, v0, v1, v2 ))
      return;
   setup_tri_coefficients( setup );
   setup_tri_edges( setup );

   setup->quad.input.prim = PRIM_TRI;

   setup->span.y = 0;
   setup->span.y_flags = 0;
   setup->span.right[0] = 0;
   setup->span.right[1] = 0;
   /*   setup->span.z_mode = tri_z_mode( setup->ctx ); */

   /*   init_constant_attribs( setup ); */

   if (setup->oneoverarea < 0.0) {
      /* emaj on left:
       */
      subtriangle( setup, &setup->emaj, &setup->ebot, setup->ebot.lines );
      subtriangle( setup, &setup->emaj, &setup->etop, setup->etop.lines );
   }
   else {
      /* emaj on right:
       */
      subtriangle( setup, &setup->ebot, &setup->emaj, setup->ebot.lines );
      subtriangle( setup, &setup->etop, &setup->emaj, setup->etop.lines );
   }

   flush_spans( setup );

   WAIT_FOR_COMPLETION(setup);

#if DEBUG_FRAGS
   printf("Tri: %u frags emitted, %u written\n",
          setup->numFragsEmitted,
          setup->numFragsWritten);
#endif

static void setup_tri_coefficients

(

struct setup_context *

setup

)

[static]

Compute the setup->coef[] array dadx, dady, a0 values.

Must be called after setup->vmin,vmid,vmax,vprovoke are initialized.

Definition at line 760 of file sp_setup.c.

{
   struct softpipe_context *softpipe = setup->softpipe;
   const struct sp_fragment_shader *spfs = softpipe->fs;
   const struct vertex_info *vinfo = softpipe_get_vertex_info(softpipe);
   uint fragSlot;

   /* z and w are done by linear interpolation:
    */
   tri_linear_coeff(setup, &setup->posCoef, 0, 2);
   tri_linear_coeff(setup, &setup->posCoef, 0, 3);

   /* setup interpolation for all the remaining attributes:
    */
   for (fragSlot = 0; fragSlot < spfs->info.num_inputs; fragSlot++) {
      const uint vertSlot = vinfo->attrib[fragSlot].src_index;
      uint j;

      switch (vinfo->attrib[fragSlot].interp_mode) {
      case INTERP_CONSTANT:
         for (j = 0; j < NUM_CHANNELS; j++)
            const_coeff(setup, &setup->coef[fragSlot], vertSlot, j);
         break;
      case INTERP_LINEAR:
         for (j = 0; j < NUM_CHANNELS; j++)
            tri_linear_coeff(setup, &setup->coef[fragSlot], vertSlot, j);
         break;
      case INTERP_PERSPECTIVE:
         for (j = 0; j < NUM_CHANNELS; j++)
            tri_persp_coeff(setup, &setup->coef[fragSlot], vertSlot, j);
         break;
      case INTERP_POS:
         setup_fragcoord_coeff(setup, fragSlot);
         break;
      default:
         assert(0);
      }

      if (spfs->info.input_semantic_name[fragSlot] == TGSI_SEMANTIC_FOG) {
         /* FOG.y = front/back facing  XXX fix this */
         setup->coef[fragSlot].a0[1] = 1.0f - setup->quad.input.facing;
         setup->coef[fragSlot].dadx[1] = 0.0;
         setup->coef[fragSlot].dady[1] = 0.0;
      }
   }

static void setup_tri_edges

(

struct setup_context *

setup

)

[static]

Definition at line 809 of file sp_setup.c.

References edge::dx, edge::dxdy, edge::dy, setup_context::ebot, setup_context::emaj, setup_context::etop, edge::lines, edge::sx, edge::sy, setup_context::vmax, setup_context::vmid, and setup_context::vmin.

{
   float vmin_x = setup->vmin[0][0] + 0.5f;
   float vmid_x = setup->vmid[0][0] + 0.5f;

   float vmin_y = setup->vmin[0][1] - 0.5f;
   float vmid_y = setup->vmid[0][1] - 0.5f;
   float vmax_y = setup->vmax[0][1] - 0.5f;

   setup->emaj.sy = ceilf(vmin_y);
   setup->emaj.lines = (int) ceilf(vmax_y - setup->emaj.sy);
   setup->emaj.dxdy = setup->emaj.dx / setup->emaj.dy;
   setup->emaj.sx = vmin_x + (setup->emaj.sy - vmin_y) * setup->emaj.dxdy;

   setup->etop.sy = ceilf(vmid_y);
   setup->etop.lines = (int) ceilf(vmax_y - setup->etop.sy);
   setup->etop.dxdy = setup->etop.dx / setup->etop.dy;
   setup->etop.sx = vmid_x + (setup->etop.sy - vmid_y) * setup->etop.dxdy;

   setup->ebot.sy = ceilf(vmin_y);
   setup->ebot.lines = (int) ceilf(vmid_y - setup->ebot.sy);
   setup->ebot.dxdy = setup->ebot.dx / setup->ebot.dy;
   setup->ebot.sx = vmin_x + (setup->ebot.sy - vmin_y) * setup->ebot.dxdy;

static void subtriangle	(	struct setup_context *	setup,
		struct edge *	eleft,
		struct edge *	eright,
		unsigned	lines
	)			[static]

Render the upper or lower half of a triangle.

Scissoring/cliprect is applied here too.

Definition at line 839 of file sp_setup.c.

{
   const struct pipe_scissor_state *cliprect = &setup->softpipe->cliprect;
   const int minx = (int) cliprect->minx;
   const int maxx = (int) cliprect->maxx;
   const int miny = (int) cliprect->miny;
   const int maxy = (int) cliprect->maxy;
   int y, start_y, finish_y;
   int sy = (int)eleft->sy;

   assert((int)eleft->sy == (int) eright->sy);

   /* clip top/bottom */
   start_y = sy;
   finish_y = sy + lines;

   if (start_y < miny)
      start_y = miny;

   if (finish_y > maxy)
      finish_y = maxy;

   start_y -= sy;
   finish_y -= sy;

   /*
   debug_printf("%s %d %d\n", __FUNCTION__, start_y, finish_y);
   */

   for (y = start_y; y < finish_y; y++) {

      /* avoid accumulating adds as floats don't have the precision to
       * accurately iterate large triangle edges that way.  luckily we
       * can just multiply these days.
       *
       * this is all drowned out by the attribute interpolation anyway.
       */
      int left = (int)(eleft->sx + y * eleft->dxdy);
      int right = (int)(eright->sx + y * eright->dxdy);

      /* clip left/right */
      if (left < minx)
         left = minx;
      if (right > maxx)
         right = maxx;

      if (left < right) {
         int _y = sy + y;
         if (block(_y) != setup->span.y) {
            flush_spans(setup);
            setup->span.y = block(_y);
         }

         setup->span.left[_y&1] = left;
         setup->span.right[_y&1] = right;
         setup->span.y_flags |= 1<<(_y&1);
      }
   }


   /* save the values so that emaj can be restarted:
    */
   eleft->sx += lines * eleft->dxdy;
   eright->sx += lines * eright->dxdy;
   eleft->sy += lines;
   eright->sy += lines;

static void tri_linear_coeff	(	struct setup_context *	setup,
		struct tgsi_interp_coef *	coef,
		uint	vertSlot,
		uint	i
	)			[static]

Compute a0, dadx and dady for a linearly interpolated coefficient, for a triangle.

Definition at line 635 of file sp_setup.c.

{
   float botda = setup->vmid[vertSlot][i] - setup->vmin[vertSlot][i];
   float majda = setup->vmax[vertSlot][i] - setup->vmin[vertSlot][i];
   float a = setup->ebot.dy * majda - botda * setup->emaj.dy;
   float b = setup->emaj.dx * botda - majda * setup->ebot.dx;
   float dadx = a * setup->oneoverarea;
   float dady = b * setup->oneoverarea;

   assert(i <= 3);

   coef->dadx[i] = dadx;
   coef->dady[i] = dady;

   /* calculate a0 as the value which would be sampled for the
    * fragment at (0,0), taking into account that we want to sample at
    * pixel centers, in other words (0.5, 0.5).
    *
    * this is neat but unfortunately not a good way to do things for
    * triangles with very large values of dadx or dady as it will
    * result in the subtraction and re-addition from a0 of a very
    * large number, which means we'll end up loosing a lot of the
    * fractional bits and precision from a0.  the way to fix this is
    * to define a0 as the sample at a pixel center somewhere near vmin
    * instead - i'll switch to this later.
    */
   coef->a0[i] = (setup->vmin[vertSlot][i] -
                  (dadx * (setup->vmin[0][0] - 0.5f) +
                   dady * (setup->vmin[0][1] - 0.5f)));

   /*
   debug_printf("attr[%d].%c: %f dx:%f dy:%f\n",
                slot, "xyzw"[i],
                setup->coef[slot].a0[i],
                setup->coef[slot].dadx[i],
                setup->coef[slot].dady[i]);
   */

static void tri_persp_coeff	(	struct setup_context *	setup,
		struct tgsi_interp_coef *	coef,
		uint	vertSlot,
		uint	i
	)			[static]

Compute a0, dadx and dady for a perspective-corrected interpolant, for a triangle.

We basically multiply the vertex value by 1/w before computing the plane coefficients (a0, dadx, dady). Later, when we compute the value at a particular fragment position we'll divide the interpolated value by the interpolated W at that fragment.

Definition at line 685 of file sp_setup.c.

{
   /* premultiply by 1/w  (v[0][3] is always W):
    */
   float mina = setup->vmin[vertSlot][i] * setup->vmin[0][3];
   float mida = setup->vmid[vertSlot][i] * setup->vmid[0][3];
   float maxa = setup->vmax[vertSlot][i] * setup->vmax[0][3];
   float botda = mida - mina;
   float majda = maxa - mina;
   float a = setup->ebot.dy * majda - botda * setup->emaj.dy;
   float b = setup->emaj.dx * botda - majda * setup->ebot.dx;
   float dadx = a * setup->oneoverarea;
   float dady = b * setup->oneoverarea;

   /*
   debug_printf("tri persp %d,%d: %f %f %f\n", vertSlot, i,
                setup->vmin[vertSlot][i],
                setup->vmid[vertSlot][i],
                setup->vmax[vertSlot][i]
          );
   */
   assert(i <= 3);

   coef->dadx[i] = dadx;
   coef->dady[i] = dady;
   coef->a0[i] = (mina -
                  (dadx * (setup->vmin[0][0] - 0.5f) +
                   dady * (setup->vmin[0][1] - 0.5f)));

---