258 lines
6.9 KiB
C
258 lines
6.9 KiB
C
/**************************************************************************
|
|
*
|
|
* 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.
|
|
*
|
|
**************************************************************************/
|
|
|
|
/**
|
|
* \brief polygon offset state
|
|
*
|
|
* \author Keith Whitwell <keithw@vmware.com>
|
|
* \author Brian Paul
|
|
*/
|
|
|
|
#include "util/format/u_format.h"
|
|
#include "util/u_math.h"
|
|
#include "util/u_memory.h"
|
|
#include "draw_pipe.h"
|
|
|
|
|
|
|
|
struct offset_stage {
|
|
struct draw_stage stage;
|
|
|
|
float scale;
|
|
float units;
|
|
float clamp;
|
|
};
|
|
|
|
|
|
|
|
static inline struct offset_stage *offset_stage( struct draw_stage *stage )
|
|
{
|
|
return (struct offset_stage *) stage;
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
/**
|
|
* Offset tri Z. Some hardware can handle this, but not usually when
|
|
* doing unfilled rendering.
|
|
*/
|
|
static void do_offset_tri( struct draw_stage *stage,
|
|
struct prim_header *header )
|
|
{
|
|
const unsigned pos = draw_current_shader_position_output(stage->draw);
|
|
struct offset_stage *offset = offset_stage(stage);
|
|
float inv_det = 1.0f / header->det;
|
|
|
|
/* Window coords:
|
|
*/
|
|
float *v0 = header->v[0]->data[pos];
|
|
float *v1 = header->v[1]->data[pos];
|
|
float *v2 = header->v[2]->data[pos];
|
|
|
|
/* edge vectors e = v0 - v2, f = v1 - v2 */
|
|
float ex = v0[0] - v2[0];
|
|
float ey = v0[1] - v2[1];
|
|
float ez = v0[2] - v2[2];
|
|
float fx = v1[0] - v2[0];
|
|
float fy = v1[1] - v2[1];
|
|
float fz = v1[2] - v2[2];
|
|
|
|
/* (a,b) = cross(e,f).xy */
|
|
float a = ey*fz - ez*fy;
|
|
float b = ez*fx - ex*fz;
|
|
|
|
float dzdx = fabsf(a * inv_det);
|
|
float dzdy = fabsf(b * inv_det);
|
|
|
|
float zoffset, mult;
|
|
|
|
mult = MAX2(dzdx, dzdy) * offset->scale;
|
|
|
|
if (stage->draw->floating_point_depth) {
|
|
float bias;
|
|
union fi maxz;
|
|
maxz.f = MAX3(fabs(v0[2]), fabs(v1[2]), fabs(v2[2]));
|
|
/* just do the math directly on shifted number */
|
|
maxz.ui &= 0xff << 23;
|
|
maxz.i -= 23 << 23;
|
|
/* Clamping to zero means mrd will be zero for very small numbers,
|
|
* but specs do not indicate this should be prevented by clamping
|
|
* mrd to smallest normal number instead. */
|
|
maxz.i = MAX2(maxz.i, 0);
|
|
|
|
bias = offset->units * maxz.f;
|
|
zoffset = bias + mult;
|
|
} else {
|
|
zoffset = offset->units + mult;
|
|
}
|
|
|
|
if (offset->clamp)
|
|
zoffset = (offset->clamp < 0.0f) ? MAX2(zoffset, offset->clamp) :
|
|
MIN2(zoffset, offset->clamp);
|
|
|
|
/*
|
|
* Note: we're applying the offset and clamping per-vertex.
|
|
* Ideally, the offset is applied per-fragment prior to fragment shading.
|
|
*/
|
|
v0[2] = SATURATE(v0[2] + zoffset);
|
|
v1[2] = SATURATE(v1[2] + zoffset);
|
|
v2[2] = SATURATE(v2[2] + zoffset);
|
|
|
|
stage->next->tri( stage->next, header );
|
|
}
|
|
|
|
|
|
static void offset_tri( struct draw_stage *stage,
|
|
struct prim_header *header )
|
|
{
|
|
struct prim_header tmp;
|
|
|
|
tmp.det = header->det;
|
|
tmp.flags = header->flags;
|
|
tmp.pad = header->pad;
|
|
tmp.v[0] = dup_vert(stage, header->v[0], 0);
|
|
tmp.v[1] = dup_vert(stage, header->v[1], 1);
|
|
tmp.v[2] = dup_vert(stage, header->v[2], 2);
|
|
|
|
do_offset_tri( stage, &tmp );
|
|
}
|
|
|
|
|
|
static void offset_first_tri( struct draw_stage *stage,
|
|
struct prim_header *header )
|
|
{
|
|
struct offset_stage *offset = offset_stage(stage);
|
|
const struct pipe_rasterizer_state *rast = stage->draw->rasterizer;
|
|
unsigned fill_mode = rast->fill_front;
|
|
boolean do_offset;
|
|
|
|
if (rast->fill_back != rast->fill_front) {
|
|
/* Need to check for back-facing triangle */
|
|
boolean ccw = header->det < 0.0f;
|
|
if (ccw != rast->front_ccw)
|
|
fill_mode = rast->fill_back;
|
|
}
|
|
|
|
/* Now determine if we need to do offsetting for the point/line/fill mode */
|
|
switch (fill_mode) {
|
|
case PIPE_POLYGON_MODE_FILL:
|
|
do_offset = rast->offset_tri;
|
|
break;
|
|
case PIPE_POLYGON_MODE_LINE:
|
|
do_offset = rast->offset_line;
|
|
break;
|
|
case PIPE_POLYGON_MODE_POINT:
|
|
do_offset = rast->offset_point;
|
|
break;
|
|
default:
|
|
assert(!"invalid fill_mode in offset_first_tri()");
|
|
do_offset = rast->offset_tri;
|
|
}
|
|
|
|
if (do_offset) {
|
|
offset->scale = rast->offset_scale;
|
|
offset->clamp = rast->offset_clamp;
|
|
|
|
/*
|
|
* If depth is floating point, depth bias is calculated with respect
|
|
* to the primitive's maximum Z value. Retain the original depth bias
|
|
* value until that stage.
|
|
*/
|
|
if (stage->draw->floating_point_depth) {
|
|
offset->units = (float) rast->offset_units;
|
|
} else {
|
|
offset->units = (float) (rast->offset_units * stage->draw->mrd * 2);
|
|
}
|
|
}
|
|
else {
|
|
offset->scale = 0.0f;
|
|
offset->clamp = 0.0f;
|
|
offset->units = 0.0f;
|
|
}
|
|
|
|
|
|
stage->tri = offset_tri;
|
|
stage->tri( stage, header );
|
|
}
|
|
|
|
|
|
|
|
|
|
static void offset_flush( struct draw_stage *stage,
|
|
unsigned flags )
|
|
{
|
|
stage->tri = offset_first_tri;
|
|
stage->next->flush( stage->next, flags );
|
|
}
|
|
|
|
|
|
static void offset_reset_stipple_counter( struct draw_stage *stage )
|
|
{
|
|
stage->next->reset_stipple_counter( stage->next );
|
|
}
|
|
|
|
|
|
static void offset_destroy( struct draw_stage *stage )
|
|
{
|
|
draw_free_temp_verts( stage );
|
|
FREE( stage );
|
|
}
|
|
|
|
|
|
/**
|
|
* Create polygon offset drawing stage.
|
|
*/
|
|
struct draw_stage *draw_offset_stage( struct draw_context *draw )
|
|
{
|
|
struct offset_stage *offset = CALLOC_STRUCT(offset_stage);
|
|
if (!offset)
|
|
goto fail;
|
|
|
|
offset->stage.draw = draw;
|
|
offset->stage.name = "offset";
|
|
offset->stage.next = NULL;
|
|
offset->stage.point = draw_pipe_passthrough_point;
|
|
offset->stage.line = draw_pipe_passthrough_line;
|
|
offset->stage.tri = offset_first_tri;
|
|
offset->stage.flush = offset_flush;
|
|
offset->stage.reset_stipple_counter = offset_reset_stipple_counter;
|
|
offset->stage.destroy = offset_destroy;
|
|
|
|
if (!draw_alloc_temp_verts( &offset->stage, 3 ))
|
|
goto fail;
|
|
|
|
return &offset->stage;
|
|
|
|
fail:
|
|
if (offset)
|
|
offset->stage.destroy( &offset->stage );
|
|
|
|
return NULL;
|
|
}
|