/**************************************************************************
*
- * 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 Clipping stage
*
- * \author Keith Whitwell <keith@tungstengraphics.com>
+ * \author Keith Whitwell <keithw@vmware.com>
*/
#include "draw_vs.h"
#include "draw_pipe.h"
+#include "draw_fs.h"
+#include "draw_gs.h"
+
+
+/** Set to 1 to enable printing of coords before/after clipping */
+#define DEBUG_CLIP 0
#ifndef IS_NEGATIVE
struct clip_stage {
struct draw_stage stage; /**< base class */
- /* Basically duplicate some of the flatshading logic here:
- */
- boolean flat;
- uint num_color_attribs;
- uint color_attribs[4]; /* front/back primary/secondary colors */
+ /* List of the attributes to be flatshaded. */
+ uint num_flat_attribs;
+ uint flat_attribs[PIPE_MAX_SHADER_OUTPUTS];
+
+ /* Mask of attributes in noperspective mode */
+ boolean noperspective_attribs[PIPE_MAX_SHADER_OUTPUTS];
float (*plane)[4];
};
return (struct clip_stage *)stage;
}
+static INLINE unsigned
+draw_viewport_index(struct draw_context *draw,
+ const struct vertex_header *leading_vertex)
+{
+ if (draw_current_shader_uses_viewport_index(draw)) {
+ unsigned viewport_index_output =
+ draw_current_shader_viewport_index_output(draw);
+ unsigned viewport_index =
+ *((unsigned*)leading_vertex->data[viewport_index_output]);
+ return draw_clamp_viewport_idx(viewport_index);
+ } else {
+ return 0;
+ }
+}
+
#define LINTERP(T, OUT, IN) ((OUT) + (T) * ((IN) - (OUT)))
float t,
const float in[4],
const float out[4] )
-{
+{
dst[0] = LINTERP( t, out[0], in[0] );
dst[1] = LINTERP( t, out[1], in[1] );
dst[2] = LINTERP( t, out[2], in[2] );
/**
- * Copy front/back, primary/secondary colors from src vertex to dst vertex.
- * Used when flat shading.
+ * Copy flat shaded attributes src vertex to dst vertex.
*/
-static void copy_colors( struct draw_stage *stage,
- struct vertex_header *dst,
- const struct vertex_header *src )
+static void copy_flat( struct draw_stage *stage,
+ struct vertex_header *dst,
+ const struct vertex_header *src )
{
const struct clip_stage *clipper = clip_stage(stage);
uint i;
- for (i = 0; i < clipper->num_color_attribs; i++) {
- const uint attr = clipper->color_attribs[i];
+ for (i = 0; i < clipper->num_flat_attribs; i++) {
+ const uint attr = clipper->flat_attribs[i];
COPY_4FV(dst->data[attr], src->data[attr]);
}
}
-
-
/* Interpolate between two vertices to produce a third.
*/
static void interp( const struct clip_stage *clip,
struct vertex_header *dst,
float t,
const struct vertex_header *out,
- const struct vertex_header *in )
+ const struct vertex_header *in,
+ unsigned viewport_index )
{
- const unsigned nr_attrs = draw_current_shader_outputs(clip->stage.draw);
+ const unsigned nr_attrs = draw_num_shader_outputs(clip->stage.draw);
const unsigned pos_attr = draw_current_shader_position_output(clip->stage.draw);
const unsigned clip_attr = draw_current_shader_clipvertex_output(clip->stage.draw);
unsigned j;
+ float t_nopersp;
/* Vertex header.
*/
*/
{
const float *pos = dst->pre_clip_pos;
- const float *scale = clip->stage.draw->viewport.scale;
- const float *trans = clip->stage.draw->viewport.translate;
+ const float *scale =
+ clip->stage.draw->viewports[viewport_index].scale;
+ const float *trans =
+ clip->stage.draw->viewports[viewport_index].translate;
const float oow = 1.0f / pos[3];
dst->data[pos_attr][0] = pos[0] * oow * scale[0] + trans[0];
dst->data[pos_attr][2] = pos[2] * oow * scale[2] + trans[2];
dst->data[pos_attr][3] = oow;
}
+
+ /**
+ * Compute the t in screen-space instead of 3d space to use
+ * for noperspective interpolation.
+ *
+ * The points can be aligned with the X axis, so in that case try
+ * the Y. When both points are at the same screen position, we can
+ * pick whatever value (the interpolated point won't be in front
+ * anyway), so just use the 3d t.
+ */
+ {
+ int k;
+ t_nopersp = t;
+ /* find either in.x != out.x or in.y != out.y */
+ for (k = 0; k < 2; k++) {
+ if (in->clip[k] != out->clip[k]) {
+ /* do divide by W, then compute linear interpolation factor */
+ float in_coord = in->clip[k] / in->clip[3];
+ float out_coord = out->clip[k] / out->clip[3];
+ float dst_coord = dst->clip[k] / dst->clip[3];
+ t_nopersp = (dst_coord - out_coord) / (in_coord - out_coord);
+ break;
+ }
+ }
+ }
/* Other attributes
*/
for (j = 0; j < nr_attrs; j++) {
- if (j != pos_attr && j != clip_attr)
- interp_attr(dst->data[j], t, in->data[j], out->data[j]);
+ if (j != pos_attr && j != clip_attr) {
+ if (clip->noperspective_attribs[j])
+ interp_attr(dst->data[j], t_nopersp, in->data[j], out->data[j]);
+ else
+ interp_attr(dst->data[j], t, in->data[j], out->data[j]);
+ }
}
}
+/**
+ * Checks whether the specifed triangle is empty and if it is returns
+ * true, otherwise returns false.
+ * Triangle is considered null/empty if it's area is qual to zero.
+ */
+static INLINE boolean
+is_tri_null(struct draw_context *draw, const struct prim_header *header)
+{
+ const unsigned pos_attr = draw_current_shader_position_output(draw);
+ float x1 = header->v[1]->data[pos_attr][0] - header->v[0]->data[pos_attr][0];
+ float y1 = header->v[1]->data[pos_attr][1] - header->v[0]->data[pos_attr][1];
+ float z1 = header->v[1]->data[pos_attr][2] - header->v[0]->data[pos_attr][2];
+
+ float x2 = header->v[2]->data[pos_attr][0] - header->v[0]->data[pos_attr][0];
+ float y2 = header->v[2]->data[pos_attr][1] - header->v[0]->data[pos_attr][1];
+ float z2 = header->v[2]->data[pos_attr][2] - header->v[0]->data[pos_attr][2];
+
+ float vx = y1 * z2 - z1 * y2;
+ float vy = x1 * z2 - z1 * x2;
+ float vz = x1 * y2 - y1 * x2;
+
+ return (vx*vx + vy*vy + vz*vz) == 0.f;
+}
/**
* Emit a post-clip polygon to the next pipeline stage. The polygon
struct prim_header header;
unsigned i;
ushort edge_first, edge_middle, edge_last;
+ boolean last_tri_was_null = FALSE;
+ boolean tri_was_not_null = FALSE;
if (stage->draw->rasterizer->flatshade_first) {
edge_first = DRAW_PIPE_EDGE_FLAG_0;
header.pad = 0;
for (i = 2; i < n; i++, header.flags = edge_middle) {
+ boolean tri_null;
/* order the triangle verts to respect the provoking vertex mode */
if (stage->draw->rasterizer->flatshade_first) {
header.v[0] = inlist[0]; /* the provoking vertex */
header.v[2] = inlist[0]; /* the provoking vertex */
}
+ tri_null = is_tri_null(stage->draw, &header);
+ /* If we generated a triangle with an area, aka. non-null triangle,
+ * or if the previous triangle was also null then skip all subsequent
+ * null triangles */
+ if ((tri_was_not_null && tri_null) || (last_tri_was_null && tri_null)) {
+ last_tri_was_null = tri_null;
+ continue;
+ }
+ last_tri_was_null = tri_null;
+ if (!tri_null) {
+ tri_was_not_null = TRUE;
+ }
+
if (!edgeflags[i-1]) {
header.flags &= ~edge_middle;
}
if (i == n - 1 && edgeflags[i])
header.flags |= edge_last;
- if (0) {
- const struct draw_vertex_shader *vs = stage->draw->vs.vertex_shader;
+ if (DEBUG_CLIP) {
uint j, k;
debug_printf("Clipped tri: (flat-shade-first = %d)\n",
stage->draw->rasterizer->flatshade_first);
for (j = 0; j < 3; j++) {
- for (k = 0; k < vs->info.num_outputs; k++) {
+ debug_printf(" Vert %d: clip: %f %f %f %f\n", j,
+ header.v[j]->clip[0],
+ header.v[j]->clip[1],
+ header.v[j]->clip[2],
+ header.v[j]->clip[3]);
+ for (k = 0; k < draw_num_shader_outputs(stage->draw); k++) {
debug_printf(" Vert %d: Attr %d: %f %f %f %f\n", j, k,
header.v[j]->data[k][0],
header.v[j]->data[k][1],
}
}
}
-
stage->next->tri( stage->next, &header );
}
}
boolean bEdges[MAX_CLIPPED_VERTICES];
boolean *inEdges = aEdges;
boolean *outEdges = bEdges;
+ int viewport_index = 0;
inlist[0] = header->v[0];
inlist[1] = header->v[1];
inlist[2] = header->v[2];
+ viewport_index = draw_viewport_index(clipper->stage.draw, inlist[0]);
+
+ if (DEBUG_CLIP) {
+ const float *v0 = header->v[0]->clip;
+ const float *v1 = header->v[1]->clip;
+ const float *v2 = header->v[2]->clip;
+ debug_printf("Clip triangle:\n");
+ debug_printf(" %f, %f, %f, %f\n", v0[0], v0[1], v0[2], v0[3]);
+ debug_printf(" %f, %f, %f, %f\n", v1[0], v1[1], v1[2], v1[3]);
+ debug_printf(" %f, %f, %f, %f\n", v2[0], v2[1], v2[2], v2[3]);
+ }
+
/*
* Note: at this point we can't just use the per-vertex edge flags.
* We have to observe the edge flag bits set in header->flags which
dp_prev = getclipdist(clipper, vert_prev, plane_idx);
clipmask &= ~(1<<plane_idx);
+ if (util_is_inf_or_nan(dp_prev))
+ return; //discard nan
+
assert(n < MAX_CLIPPED_VERTICES);
if (n >= MAX_CLIPPED_VERTICES)
return;
float dp = getclipdist(clipper, vert, plane_idx);
+ if (util_is_inf_or_nan(dp))
+ return; //discard nan
+
if (!IS_NEGATIVE(dp_prev)) {
assert(outcount < MAX_CLIPPED_VERTICES);
if (outcount >= MAX_CLIPPED_VERTICES)
* know dp != dp_prev from DIFFERENT_SIGNS, above.
*/
float t = dp / (dp - dp_prev);
- interp( clipper, new_vert, t, vert, vert_prev );
+ interp( clipper, new_vert, t, vert, vert_prev, viewport_index );
/* Whether or not to set edge flag for the new vert depends
* on whether it's a user-defined clipping plane. We're
/* Coming back in.
*/
float t = dp_prev / (dp_prev - dp);
- interp( clipper, new_vert, t, vert_prev, vert );
+ interp( clipper, new_vert, t, vert_prev, vert, viewport_index );
/* Copy starting vert's edgeflag:
*/
/* If flat-shading, copy provoking vertex color to polygon vertex[0]
*/
if (n >= 3) {
- if (clipper->flat) {
+ if (clipper->num_flat_attribs) {
if (stage->draw->rasterizer->flatshade_first) {
if (inlist[0] != header->v[0]) {
assert(tmpnr < MAX_CLIPPED_VERTICES + 1);
if (tmpnr >= MAX_CLIPPED_VERTICES + 1)
return;
inlist[0] = dup_vert(stage, inlist[0], tmpnr++);
- copy_colors(stage, inlist[0], header->v[0]);
+ copy_flat(stage, inlist[0], header->v[0]);
}
}
else {
if (tmpnr >= MAX_CLIPPED_VERTICES + 1)
return;
inlist[0] = dup_vert(stage, inlist[0], tmpnr++);
- copy_colors(stage, inlist[0], header->v[2]);
+ copy_flat(stage, inlist[0], header->v[2]);
}
}
}
float t0 = 0.0F;
float t1 = 0.0F;
struct prim_header newprim;
+ int viewport_index = draw_viewport_index(clipper->stage.draw, v0);
while (clipmask) {
const unsigned plane_idx = ffs(clipmask)-1;
const float dp0 = getclipdist(clipper, v0, plane_idx);
const float dp1 = getclipdist(clipper, v1, plane_idx);
+ if (util_is_inf_or_nan(dp0) || util_is_inf_or_nan(dp1))
+ return; //discard nan
+
if (dp1 < 0.0F) {
float t = dp1 / (dp1 - dp0);
t1 = MAX2(t1, t);
}
if (v0->clipmask) {
- interp( clipper, stage->tmp[0], t0, v0, v1 );
-
- if (clipper->flat)
- copy_colors(stage, stage->tmp[0], v0);
-
+ interp( clipper, stage->tmp[0], t0, v0, v1, viewport_index );
+ if (stage->draw->rasterizer->flatshade_first) {
+ copy_flat(stage, stage->tmp[0], v0); /* copy v0 color to tmp[0] */
+ }
+ else {
+ copy_flat(stage, stage->tmp[0], v1); /* copy v1 color to tmp[0] */
+ }
newprim.v[0] = stage->tmp[0];
}
else {
}
if (v1->clipmask) {
- interp( clipper, stage->tmp[1], t1, v1, v0 );
+ interp( clipper, stage->tmp[1], t1, v1, v0, viewport_index );
+ if (stage->draw->rasterizer->flatshade_first) {
+ copy_flat(stage, stage->tmp[1], v0); /* copy v0 color to tmp[1] */
+ }
+ else {
+ copy_flat(stage, stage->tmp[1], v1); /* copy v1 color to tmp[1] */
+ }
newprim.v[1] = stage->tmp[1];
}
else {
static void
clip_point( struct draw_stage *stage,
- struct prim_header *header )
+ struct prim_header *header )
{
- if (header->v[0]->clipmask == 0)
+ if (header->v[0]->clipmask == 0)
stage->next->point( stage->next, header );
}
+/*
+ * Clip points but ignore the first 4 (xy) clip planes.
+ * (Because the generated clip mask is completely unaffacted by guard band,
+ * we still need to manually evaluate the x/y planes if they are outside
+ * the guard band and not just outside the vp.)
+ */
+static void
+clip_point_guard_xy( struct draw_stage *stage,
+ struct prim_header *header )
+{
+ unsigned clipmask = header->v[0]->clipmask;
+ if ((clipmask & 0xffffffff) == 0)
+ stage->next->point(stage->next, header);
+ else if ((clipmask & 0xfffffff0) == 0) {
+ while (clipmask) {
+ const unsigned plane_idx = ffs(clipmask)-1;
+ clipmask &= ~(1 << plane_idx); /* turn off this plane's bit */
+ /* TODO: this should really do proper guardband clipping,
+ * currently just throw out infs/nans.
+ * Also note that vertices with negative w values MUST be tossed
+ * out (not sure if proper guardband clipping would do this
+ * automatically). These would usually be captured by depth clip
+ * too but this can be disabled.
+ */
+ if (header->v[0]->clip[3] <= 0.0f ||
+ util_is_inf_or_nan(header->v[0]->clip[0]) ||
+ util_is_inf_or_nan(header->v[0]->clip[1]))
+ return;
+ }
+ stage->next->point(stage->next, header);
+ }
+}
+
+
+static void
+clip_first_point( struct draw_stage *stage,
+ struct prim_header *header )
+{
+ stage->point = stage->draw->guard_band_points_xy ? clip_point_guard_xy : clip_point;
+ stage->point(stage, header);
+}
+
+
static void
clip_line( struct draw_stage *stage,
struct prim_header *header )
{
unsigned clipmask = (header->v[0]->clipmask |
header->v[1]->clipmask);
-
+
if (clipmask == 0) {
/* no clipping needed */
stage->next->line( stage->next, header );
static void
clip_tri( struct draw_stage *stage,
- struct prim_header *header )
+ struct prim_header *header )
{
unsigned clipmask = (header->v[0]->clipmask |
header->v[1]->clipmask |
header->v[2]->clipmask);
-
+
if (clipmask == 0) {
/* no clipping needed */
stage->next->tri( stage->next, header );
}
+static int
+find_interp(const struct draw_fragment_shader *fs, int *indexed_interp,
+ uint semantic_name, uint semantic_index)
+{
+ int interp;
+ /* If it's gl_{Front,Back}{,Secondary}Color, pick up the mode
+ * from the array we've filled before. */
+ if (semantic_name == TGSI_SEMANTIC_COLOR ||
+ semantic_name == TGSI_SEMANTIC_BCOLOR) {
+ interp = indexed_interp[semantic_index];
+ } else {
+ /* Otherwise, search in the FS inputs, with a decent default
+ * if we don't find it.
+ */
+ uint j;
+ interp = TGSI_INTERPOLATE_PERSPECTIVE;
+ if (fs) {
+ for (j = 0; j < fs->info.num_inputs; j++) {
+ if (semantic_name == fs->info.input_semantic_name[j] &&
+ semantic_index == fs->info.input_semantic_index[j]) {
+ interp = fs->info.input_interpolate[j];
+ break;
+ }
+ }
+ }
+ }
+ return interp;
+}
+
/* Update state. Could further delay this until we hit the first
* primitive that really requires clipping.
*/
clip_init_state( struct draw_stage *stage )
{
struct clip_stage *clipper = clip_stage( stage );
+ const struct draw_fragment_shader *fs = stage->draw->fs.fragment_shader;
+ uint i, j;
+ const struct tgsi_shader_info *info = draw_get_shader_info(stage->draw);
+
+ /* We need to know for each attribute what kind of interpolation is
+ * done on it (flat, smooth or noperspective). But the information
+ * is not directly accessible for outputs, only for inputs. So we
+ * have to match semantic name and index between the VS (or GS/ES)
+ * outputs and the FS inputs to get to the interpolation mode.
+ *
+ * The only hitch is with gl_FrontColor/gl_BackColor which map to
+ * gl_Color, and their Secondary versions. First there are (up to)
+ * two outputs for one input, so we tuck the information in a
+ * specific array. Second if they don't have qualifiers, the
+ * default value has to be picked from the global shade mode.
+ *
+ * Of course, if we don't have a fragment shader in the first
+ * place, defaults should be used.
+ */
- clipper->flat = stage->draw->rasterizer->flatshade ? TRUE : FALSE;
+ /* First pick up the interpolation mode for
+ * gl_Color/gl_SecondaryColor, with the correct default.
+ */
+ int indexed_interp[2];
+ indexed_interp[0] = indexed_interp[1] = stage->draw->rasterizer->flatshade ?
+ TGSI_INTERPOLATE_CONSTANT : TGSI_INTERPOLATE_PERSPECTIVE;
+
+ if (fs) {
+ for (i = 0; i < fs->info.num_inputs; i++) {
+ if (fs->info.input_semantic_name[i] == TGSI_SEMANTIC_COLOR) {
+ if (fs->info.input_interpolate[i] != TGSI_INTERPOLATE_COLOR)
+ indexed_interp[fs->info.input_semantic_index[i]] = fs->info.input_interpolate[i];
+ }
+ }
+ }
- if (clipper->flat) {
- const struct draw_vertex_shader *vs = stage->draw->vs.vertex_shader;
- uint i;
+ /* Then resolve the interpolation mode for every output attribute.
+ *
+ * Given how the rest of the code, the most efficient way is to
+ * have a vector of flat-mode attributes, and a mask for
+ * noperspective attributes.
+ */
- clipper->num_color_attribs = 0;
- for (i = 0; i < vs->info.num_outputs; i++) {
- if (vs->info.output_semantic_name[i] == TGSI_SEMANTIC_COLOR ||
- vs->info.output_semantic_name[i] == TGSI_SEMANTIC_BCOLOR) {
- clipper->color_attribs[clipper->num_color_attribs++] = i;
- }
- }
+ clipper->num_flat_attribs = 0;
+ memset(clipper->noperspective_attribs, 0, sizeof(clipper->noperspective_attribs));
+ for (i = 0; i < info->num_outputs; i++) {
+ /* Find the interpolation mode for a specific attribute */
+ int interp = find_interp(fs, indexed_interp,
+ info->output_semantic_name[i],
+ info->output_semantic_index[i]);
+ /* If it's flat, add it to the flat vector. Otherwise update
+ * the noperspective mask.
+ */
+
+ if (interp == TGSI_INTERPOLATE_CONSTANT) {
+ clipper->flat_attribs[clipper->num_flat_attribs] = i;
+ clipper->num_flat_attribs++;
+ } else
+ clipper->noperspective_attribs[i] = interp == TGSI_INTERPOLATE_LINEAR;
+ }
+ /* Search the extra vertex attributes */
+ for (j = 0; j < stage->draw->extra_shader_outputs.num; j++) {
+ /* Find the interpolation mode for a specific attribute */
+ int interp = find_interp(fs, indexed_interp,
+ stage->draw->extra_shader_outputs.semantic_name[j],
+ stage->draw->extra_shader_outputs.semantic_index[j]);
+ /* If it's flat, add it to the flat vector. Otherwise update
+ * the noperspective mask.
+ */
+ if (interp == TGSI_INTERPOLATE_CONSTANT) {
+ clipper->flat_attribs[clipper->num_flat_attribs] = i + j;
+ clipper->num_flat_attribs++;
+ } else
+ clipper->noperspective_attribs[i + j] = interp == TGSI_INTERPOLATE_LINEAR;
}
stage->tri = clip_tri;
clipper->stage.draw = draw;
clipper->stage.name = "clipper";
- clipper->stage.point = clip_point;
+ clipper->stage.point = clip_first_point;
clipper->stage.line = clip_first_line;
clipper->stage.tri = clip_first_tri;
clipper->stage.flush = clip_flush;
projects / mesa.git / blobdiff