0,0 → 1,261 |
/************************************************************************** |
* |
* Copyright 2007 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, sub license, 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 NON-INFRINGEMENT. |
* IN NO EVENT SHALL VMWARE 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 <keithw@vmware.com> |
*/ |
|
/* Implement line stipple by cutting lines up into smaller lines. |
* There are hundreds of ways to implement line stipple, this is one |
* choice that should work in all situations, requires no state |
* manipulations, but with a penalty in terms of large amounts of |
* generated geometry. |
*/ |
|
|
#include "pipe/p_defines.h" |
#include "pipe/p_shader_tokens.h" |
#include "util/u_math.h" |
#include "util/u_memory.h" |
|
#include "draw/draw_pipe.h" |
|
|
/** Subclass of draw_stage */ |
struct stipple_stage { |
struct draw_stage stage; |
float counter; |
uint pattern; |
uint factor; |
}; |
|
|
static INLINE struct stipple_stage * |
stipple_stage(struct draw_stage *stage) |
{ |
return (struct stipple_stage *) stage; |
} |
|
|
/** |
* Compute interpolated vertex attributes for 'dst' at position 't' |
* between 'v0' and 'v1'. |
* XXX using linear interpolation for all attribs at this time. |
*/ |
static void |
screen_interp( struct draw_context *draw, |
struct vertex_header *dst, |
float t, |
const struct vertex_header *v0, |
const struct vertex_header *v1 ) |
{ |
uint attr; |
uint num_outputs = draw_current_shader_outputs(draw); |
for (attr = 0; attr < num_outputs; attr++) { |
const float *val0 = v0->data[attr]; |
const float *val1 = v1->data[attr]; |
float *newv = dst->data[attr]; |
uint i; |
for (i = 0; i < 4; i++) { |
newv[i] = val0[i] + t * (val1[i] - val0[i]); |
} |
} |
} |
|
|
static void |
emit_segment(struct draw_stage *stage, struct prim_header *header, |
float t0, float t1) |
{ |
struct vertex_header *v0new = dup_vert(stage, header->v[0], 0); |
struct vertex_header *v1new = dup_vert(stage, header->v[1], 1); |
struct prim_header newprim = *header; |
|
if (t0 > 0.0) { |
screen_interp( stage->draw, v0new, t0, header->v[0], header->v[1] ); |
newprim.v[0] = v0new; |
} |
|
if (t1 < 1.0) { |
screen_interp( stage->draw, v1new, t1, header->v[0], header->v[1] ); |
newprim.v[1] = v1new; |
} |
|
stage->next->line( stage->next, &newprim ); |
} |
|
|
static INLINE unsigned |
stipple_test(int counter, ushort pattern, int factor) |
{ |
int b = (counter / factor) & 0xf; |
return (1 << b) & pattern; |
} |
|
|
static void |
stipple_line(struct draw_stage *stage, struct prim_header *header) |
{ |
struct stipple_stage *stipple = stipple_stage(stage); |
struct vertex_header *v0 = header->v[0]; |
struct vertex_header *v1 = header->v[1]; |
const unsigned pos = draw_current_shader_position_output(stage->draw); |
const float *pos0 = v0->data[pos]; |
const float *pos1 = v1->data[pos]; |
float start = 0; |
int state = 0; |
|
float x0 = pos0[0]; |
float x1 = pos1[0]; |
float y0 = pos0[1]; |
float y1 = pos1[1]; |
|
float dx = x0 > x1 ? x0 - x1 : x1 - x0; |
float dy = y0 > y1 ? y0 - y1 : y1 - y0; |
|
float length = MAX2(dx, dy); |
int i; |
|
if (header->flags & DRAW_PIPE_RESET_STIPPLE) |
stipple->counter = 0; |
|
|
/* XXX ToDo: intead of iterating pixel-by-pixel, use a look-up table. |
*/ |
for (i = 0; i < length; i++) { |
int result = stipple_test( (int) stipple->counter+i, |
(ushort) stipple->pattern, stipple->factor ); |
if (result != state) { |
/* changing from "off" to "on" or vice versa */ |
if (state) { |
if (start != i) { |
/* finishing an "on" segment */ |
emit_segment( stage, header, start / length, i / length ); |
} |
} |
else { |
/* starting an "on" segment */ |
start = (float) i; |
} |
state = result; |
} |
} |
|
if (state && start < length) |
emit_segment( stage, header, start / length, 1.0 ); |
|
stipple->counter += length; |
} |
|
|
static void |
reset_stipple_counter(struct draw_stage *stage) |
{ |
struct stipple_stage *stipple = stipple_stage(stage); |
stipple->counter = 0; |
stage->next->reset_stipple_counter( stage->next ); |
} |
|
static void |
stipple_reset_point(struct draw_stage *stage, struct prim_header *header) |
{ |
struct stipple_stage *stipple = stipple_stage(stage); |
stipple->counter = 0; |
stage->next->point(stage->next, header); |
} |
|
static void |
stipple_reset_tri(struct draw_stage *stage, struct prim_header *header) |
{ |
struct stipple_stage *stipple = stipple_stage(stage); |
stipple->counter = 0; |
stage->next->tri(stage->next, header); |
} |
|
|
static void |
stipple_first_line(struct draw_stage *stage, |
struct prim_header *header) |
{ |
struct stipple_stage *stipple = stipple_stage(stage); |
struct draw_context *draw = stage->draw; |
|
stipple->pattern = draw->rasterizer->line_stipple_pattern; |
stipple->factor = draw->rasterizer->line_stipple_factor + 1; |
|
stage->line = stipple_line; |
stage->line( stage, header ); |
} |
|
|
static void |
stipple_flush(struct draw_stage *stage, unsigned flags) |
{ |
stage->line = stipple_first_line; |
stage->next->flush( stage->next, flags ); |
} |
|
|
|
|
static void |
stipple_destroy( struct draw_stage *stage ) |
{ |
draw_free_temp_verts( stage ); |
FREE( stage ); |
} |
|
|
/** |
* Create line stippler stage |
*/ |
struct draw_stage *draw_stipple_stage( struct draw_context *draw ) |
{ |
struct stipple_stage *stipple = CALLOC_STRUCT(stipple_stage); |
if (stipple == NULL) |
goto fail; |
|
stipple->stage.draw = draw; |
stipple->stage.name = "stipple"; |
stipple->stage.next = NULL; |
stipple->stage.point = stipple_reset_point; |
stipple->stage.line = stipple_first_line; |
stipple->stage.tri = stipple_reset_tri; |
stipple->stage.reset_stipple_counter = reset_stipple_counter; |
stipple->stage.flush = stipple_flush; |
stipple->stage.destroy = stipple_destroy; |
|
if (!draw_alloc_temp_verts( &stipple->stage, 2 )) |
goto fail; |
|
return &stipple->stage; |
|
fail: |
if (stipple) |
stipple->stage.destroy( &stipple->stage ); |
|
return NULL; |
} |