draw_pipe_wide_line.c File Reference

Include dependency graph for draw_pipe_wide_line.c:

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Data Structures
struct	wideline_stage
Functions
static struct wideline_stage *	wideline_stage (struct draw_stage *stage)
static void	wideline_line (struct draw_stage *stage, struct prim_header *header)
	Draw a wide line by drawing a quad (two triangles).
static void	wideline_flush (struct draw_stage *stage, unsigned flags)
static void	wideline_reset_stipple_counter (struct draw_stage *stage)
static void	wideline_destroy (struct draw_stage *stage)
struct draw_stage *	draw_wide_line_stage (struct draw_context *draw)

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Function Documentation

struct draw_stage* draw_wide_line_stage

(

struct draw_context *

draw

)

[read]

Definition at line 164 of file draw_pipe_wide_line.c.

References CALLOC_STRUCT, draw_stage::destroy, draw_stage::draw, draw_alloc_temp_verts(), draw_pipe_passthrough_point(), draw_pipe_passthrough_tri(), draw_stage::flush, draw_stage::line, draw_stage::next, draw_stage::point, draw_stage::reset_stipple_counter, wideline_stage::stage, draw_stage::tri, wideline_destroy(), wideline_flush(), wideline_line(), and wideline_reset_stipple_counter().

{
   struct wideline_stage *wide = CALLOC_STRUCT(wideline_stage);

   draw_alloc_temp_verts( &wide->stage, 4 );

   wide->stage.draw = draw;
   wide->stage.next = NULL;
   wide->stage.point = draw_pipe_passthrough_point;
   wide->stage.line = wideline_line;
   wide->stage.tri = draw_pipe_passthrough_tri;
   wide->stage.flush = wideline_flush;
   wide->stage.reset_stipple_counter = wideline_reset_stipple_counter;
   wide->stage.destroy = wideline_destroy;

   return &wide->stage;
}

static void wideline_destroy

(

struct draw_stage *

stage

)

[static]

Definition at line 157 of file draw_pipe_wide_line.c.

References draw_free_temp_verts(), and FREE.

{
   draw_free_temp_verts( stage );
   FREE( stage );
}

static void wideline_flush	(	struct draw_stage *	stage,
		unsigned	flags
	)			[static]

Definition at line 145 of file draw_pipe_wide_line.c.

References draw_stage::flush, and draw_stage::next.

{
   stage->next->flush( stage->next, flags );
}

static void wideline_line	(	struct draw_stage *	stage,
		struct prim_header *	header
	)			[static]

Draw a wide line by drawing a quad (two triangles).

XXX need to disable polygon stipple.

Definition at line 58 of file draw_pipe_wide_line.c.

References vertex_header::data, prim_header::det, draw_stage::draw, dup_vert(), pipe_rasterizer_state::line_width, draw_stage::next, draw_context::position_output, draw_context::rasterizer, draw_stage::tri, prim_header::v, and draw_context::vs.

{
   /*const struct wideline_stage *wide = wideline_stage(stage);*/
   const unsigned pos = stage->draw->vs.position_output;
   const float half_width = 0.5f * stage->draw->rasterizer->line_width;

   struct prim_header tri;

   struct vertex_header *v0 = dup_vert(stage, header->v[0], 0);
   struct vertex_header *v1 = dup_vert(stage, header->v[0], 1);
   struct vertex_header *v2 = dup_vert(stage, header->v[1], 2);
   struct vertex_header *v3 = dup_vert(stage, header->v[1], 3);

   float *pos0 = v0->data[pos];
   float *pos1 = v1->data[pos];
   float *pos2 = v2->data[pos];
   float *pos3 = v3->data[pos];

   const float dx = fabsf(pos0[0] - pos2[0]);
   const float dy = fabsf(pos0[1] - pos2[1]);

   /* small tweak to meet GL specification */
   const float bias = 0.125f;

   /*
    * Draw wide line as a quad (two tris) by "stretching" the line along
    * X or Y.
    * We need to tweak coords in several ways to be conformant here.
    */

   if (dx > dy) {
      /* x-major line */
      pos0[1] = pos0[1] - half_width - bias;
      pos1[1] = pos1[1] + half_width - bias;
      pos2[1] = pos2[1] - half_width - bias;
      pos3[1] = pos3[1] + half_width - bias;
      if (pos0[0] < pos2[0]) {
         /* left to right line */
         pos0[0] -= 0.5f;
         pos1[0] -= 0.5f;
         pos2[0] -= 0.5f;
         pos3[0] -= 0.5f;
      }
      else {
         /* right to left line */
         pos0[0] += 0.5f;
         pos1[0] += 0.5f;
         pos2[0] += 0.5f;
         pos3[0] += 0.5f;
      }
   }
   else {
      /* y-major line */
      pos0[0] = pos0[0] - half_width + bias;
      pos1[0] = pos1[0] + half_width + bias;
      pos2[0] = pos2[0] - half_width + bias;
      pos3[0] = pos3[0] + half_width + bias;
      if (pos0[1] < pos2[1]) {
         /* top to bottom line */
         pos0[1] -= 0.5f;
         pos1[1] -= 0.5f;
         pos2[1] -= 0.5f;
         pos3[1] -= 0.5f;
      }
      else {
         /* bottom to top line */
         pos0[1] += 0.5f;
         pos1[1] += 0.5f;
         pos2[1] += 0.5f;
         pos3[1] += 0.5f;
      }
   }

   tri.det = header->det;  /* only the sign matters */
   tri.v[0] = v0;
   tri.v[1] = v2;
   tri.v[2] = v3;
   stage->next->tri( stage->next, &tri );

   tri.v[0] = v0;
   tri.v[1] = v3;
   tri.v[2] = v1;
   stage->next->tri( stage->next, &tri );
}

static void wideline_reset_stipple_counter

(

struct draw_stage *

stage

)

[static]

Definition at line 151 of file draw_pipe_wide_line.c.

References draw_stage::next, and draw_stage::reset_stipple_counter.

{
   stage->next->reset_stipple_counter( stage->next );
}

static struct wideline_stage* wideline_stage

(

struct draw_stage *

stage

)

[static, read]

Definition at line 47 of file draw_pipe_wide_line.c.

{
   return (struct wideline_stage *)stage;
}

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