/**************************************************************************
*
- * Copyright 2007 Tungsten Graphics, Inc., Cedar Park, Texas.
+ * Copyright 2007 VMware, Inc.
* All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* 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 TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS BE LIABLE FOR
+ * 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 <keith@tungstengraphics.com>
+ * \author Keith Whitwell <keithw@vmware.com>
* \author Brian Paul
*/
+#include "util/u_format.h"
#include "util/u_math.h"
#include "util/u_memory.h"
#include "draw_pipe.h"
float scale;
float units;
+ float clamp;
};
-static INLINE struct offset_stage *offset_stage( struct draw_stage *stage )
+static inline struct offset_stage *offset_stage( struct draw_stage *stage )
{
return (struct offset_stage *) stage;
}
static void do_offset_tri( struct draw_stage *stage,
struct prim_header *header )
{
- const unsigned pos = stage->draw->vs.position_output;
+ const unsigned pos = draw_current_shader_position_output(stage->draw);
struct offset_stage *offset = offset_stage(stage);
float inv_det = 1.0f / header->det;
float dzdx = fabsf(a * inv_det);
float dzdy = fabsf(b * inv_det);
- float zoffset = offset->units + MAX2(dzdx, dzdy) * offset->scale;
+ float zoffset, mult;
+
+ mult = MAX2(dzdx, dzdy) * offset->scale;
+
+ if (stage->draw->floating_point_depth) {
+ float bias;
+ union fi maxz;
+ maxz.f = MAX3(v0[2], v1[2], 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.
struct prim_header *header )
{
struct offset_stage *offset = offset_stage(stage);
- float mrd = 1.0f / 65535.0f; /* XXX this depends on depthbuffer bits! */
+ 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);
+ }
+ }
+ else {
+ offset->scale = 0.0f;
+ offset->clamp = 0.0f;
+ offset->units = 0.0f;
+ }
- offset->units = stage->draw->rasterizer->offset_units * mrd;
- offset->scale = stage->draw->rasterizer->offset_scale;
stage->tri = offset_tri;
stage->tri( stage, header );
struct draw_stage *draw_offset_stage( struct draw_context *draw )
{
struct offset_stage *offset = CALLOC_STRUCT(offset_stage);
- if (offset == NULL)
+ if (!offset)
goto fail;
- draw_alloc_temp_verts( &offset->stage, 3 );
-
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.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:
+fail:
if (offset)
offset->stage.destroy( &offset->stage );