#define DIFFERENT_SIGNS(x, y) ((x) * (y) <= 0.0F && (x) - (y) != 0.0F)
#endif
-#ifndef MAX_CLIPPED_VERTICES
#define MAX_CLIPPED_VERTICES ((2 * (6 + PIPE_MAX_CLIP_PLANES))+1)
-#endif
-struct clipper {
+struct clip_stage {
struct draw_stage stage; /**< base class */
/* Basically duplicate some of the flatshading logic here:
};
-/* This is a bit confusing:
- */
-static INLINE struct clipper *clipper_stage( struct draw_stage *stage )
+/** Cast wrapper */
+static INLINE struct clip_stage *clip_stage( struct draw_stage *stage )
{
- return (struct clipper *)stage;
+ return (struct clip_stage *)stage;
}
/* All attributes are float[4], so this is easy:
*/
-static void interp_attr( float *fdst,
+static void interp_attr( float dst[4],
float t,
- const float *fin,
- const float *fout )
+ const float in[4],
+ const float out[4] )
{
- fdst[0] = LINTERP( t, fout[0], fin[0] );
- fdst[1] = LINTERP( t, fout[1], fin[1] );
- fdst[2] = LINTERP( t, fout[2], fin[2] );
- fdst[3] = LINTERP( t, fout[3], fin[3] );
+ dst[0] = LINTERP( t, out[0], in[0] );
+ dst[1] = LINTERP( t, out[1], in[1] );
+ dst[2] = LINTERP( t, out[2], in[2] );
+ dst[3] = LINTERP( t, out[3], in[3] );
}
+
+/**
+ * Copy front/back, primary/secondary colors from src vertex to dst vertex.
+ * Used when flat shading.
+ */
static void copy_colors( struct draw_stage *stage,
struct vertex_header *dst,
const struct vertex_header *src )
{
- const struct clipper *clipper = clipper_stage(stage);
+ 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];
/* Interpolate between two vertices to produce a third.
*/
-static void interp( const struct clipper *clip,
+static void interp( const struct clip_stage *clip,
struct vertex_header *dst,
float t,
const struct vertex_header *out,
/* Vertex header.
*/
- {
- dst->clipmask = 0;
- dst->edgeflag = 0; /* will get overwritten later */
- dst->pad = 0;
- dst->vertex_id = UNDEFINED_VERTEX_ID;
- }
+ dst->clipmask = 0;
+ dst->edgeflag = 0; /* will get overwritten later */
+ dst->pad = 0;
+ dst->vertex_id = UNDEFINED_VERTEX_ID;
- /* Clip coordinates: interpolate normally
+ /* Interpolate the clip-space coords.
*/
- {
- interp_attr(dst->clip, t, in->clip, out->clip);
- }
+ interp_attr(dst->clip, t, in->clip, out->clip);
- /* Do the projective divide and insert window coordinates:
+ /* Do the projective divide and viewport transformation to get
+ * new window coordinates:
*/
{
const float *pos = dst->clip;
}
+/**
+ * Emit a post-clip polygon to the next pipeline stage. The polygon
+ * will be convex and the provoking vertex will always be vertex[0].
+ */
static void emit_poly( struct draw_stage *stage,
struct vertex_header **inlist,
+ const boolean *edgeflags,
unsigned n,
const struct prim_header *origPrim)
{
struct prim_header header;
unsigned i;
+ ushort edge_first, edge_middle, edge_last;
- const ushort edge_first = DRAW_PIPE_EDGE_FLAG_2;
- const ushort edge_middle = DRAW_PIPE_EDGE_FLAG_0;
- const ushort edge_last = DRAW_PIPE_EDGE_FLAG_1;
+ if (stage->draw->rasterizer->flatshade_first) {
+ edge_first = DRAW_PIPE_EDGE_FLAG_0;
+ edge_middle = DRAW_PIPE_EDGE_FLAG_1;
+ edge_last = DRAW_PIPE_EDGE_FLAG_2;
+ }
+ else {
+ edge_first = DRAW_PIPE_EDGE_FLAG_2;
+ edge_middle = DRAW_PIPE_EDGE_FLAG_0;
+ edge_last = DRAW_PIPE_EDGE_FLAG_1;
+ }
+
+ if (!edgeflags[0])
+ edge_first = 0;
/* later stages may need the determinant, but only the sign matters */
header.det = origPrim->det;
header.pad = 0;
for (i = 2; i < n; i++, header.flags = edge_middle) {
- header.v[0] = inlist[i-1];
- header.v[1] = inlist[i];
- header.v[2] = inlist[0]; /* keep in v[2] for flatshading */
+ /* 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[1] = inlist[i-1];
+ header.v[2] = inlist[i];
+ }
+ else {
+ header.v[0] = inlist[i-1];
+ header.v[1] = inlist[i];
+ header.v[2] = inlist[0]; /* the provoking vertex */
+ }
- if (i == n-1)
- header.flags |= edge_last;
+ 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;
uint j, k;
- debug_printf("Clipped tri:\n");
+ 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: Attr %d: %f %f %f %f\n", j, k,
}
}
+
static INLINE float
dot4(const float *a, const float *b)
{
- return (a[0]*b[0] +
- a[1]*b[1] +
- a[2]*b[2] +
- a[3]*b[3]);
+ return (a[0] * b[0] +
+ a[1] * b[1] +
+ a[2] * b[2] +
+ a[3] * b[3]);
}
struct prim_header *header,
unsigned clipmask )
{
- struct clipper *clipper = clipper_stage( stage );
+ struct clip_stage *clipper = clip_stage( stage );
struct vertex_header *a[MAX_CLIPPED_VERTICES];
struct vertex_header *b[MAX_CLIPPED_VERTICES];
struct vertex_header **inlist = a;
unsigned tmpnr = 0;
unsigned n = 3;
unsigned i;
+ boolean aEdges[MAX_CLIPPED_VERTICES];
+ boolean bEdges[MAX_CLIPPED_VERTICES];
+ boolean *inEdges = aEdges;
+ boolean *outEdges = bEdges;
inlist[0] = header->v[0];
inlist[1] = header->v[1];
inlist[2] = header->v[2];
+ /*
+ * 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
+ * were set during primitive decomposition. Put those flags into
+ * an edge flags array which parallels the vertex array.
+ * Later, in the 'unfilled' pipeline stage we'll draw the edge if both
+ * the header.flags bit is set AND the per-vertex edgeflag field is set.
+ */
+ inEdges[0] = !!(header->flags & DRAW_PIPE_EDGE_FLAG_0);
+ inEdges[1] = !!(header->flags & DRAW_PIPE_EDGE_FLAG_1);
+ inEdges[2] = !!(header->flags & DRAW_PIPE_EDGE_FLAG_2);
+
while (clipmask && n >= 3) {
const unsigned plane_idx = ffs(clipmask)-1;
+ const boolean is_user_clip_plane = plane_idx >= 6;
const float *plane = clipper->plane[plane_idx];
struct vertex_header *vert_prev = inlist[0];
+ boolean *edge_prev = &inEdges[0];
float dp_prev = dot4( vert_prev->clip, plane );
unsigned outcount = 0;
clipmask &= ~(1<<plane_idx);
+ assert(n < MAX_CLIPPED_VERTICES);
+ if (n >= MAX_CLIPPED_VERTICES)
+ return;
inlist[n] = inlist[0]; /* prevent rotation of vertices */
+ inEdges[n] = inEdges[0];
for (i = 1; i <= n; i++) {
struct vertex_header *vert = inlist[i];
+ boolean *edge = &inEdges[i];
float dp = dot4( vert->clip, plane );
if (!IS_NEGATIVE(dp_prev)) {
+ assert(outcount < MAX_CLIPPED_VERTICES);
+ if (outcount >= MAX_CLIPPED_VERTICES)
+ return;
+ outEdges[outcount] = *edge_prev;
outlist[outcount++] = vert_prev;
}
if (DIFFERENT_SIGNS(dp, dp_prev)) {
- struct vertex_header *new_vert = clipper->stage.tmp[tmpnr++];
+ struct vertex_header *new_vert;
+ boolean *new_edge;
+
+ assert(tmpnr < MAX_CLIPPED_VERTICES + 1);
+ if (tmpnr >= MAX_CLIPPED_VERTICES + 1)
+ return;
+ new_vert = clipper->stage.tmp[tmpnr++];
+
+ assert(outcount < MAX_CLIPPED_VERTICES);
+ if (outcount >= MAX_CLIPPED_VERTICES)
+ return;
+
+ new_edge = &outEdges[outcount];
outlist[outcount++] = new_vert;
if (IS_NEGATIVE(dp)) {
float t = dp / (dp - dp_prev);
interp( clipper, new_vert, t, vert, vert_prev );
- /* Force edgeflag true in this case:
+ /* Whether or not to set edge flag for the new vert depends
+ * on whether it's a user-defined clipping plane. We're
+ * copying NVIDIA's behaviour here.
*/
- new_vert->edgeflag = 1;
- } else {
+ if (is_user_clip_plane) {
+ /* we want to see an edge along the clip plane */
+ *new_edge = TRUE;
+ new_vert->edgeflag = TRUE;
+ }
+ else {
+ /* we don't want to see an edge along the frustum clip plane */
+ *new_edge = *edge_prev;
+ new_vert->edgeflag = FALSE;
+ }
+ }
+ else {
/* Coming back in.
*/
float t = dp_prev / (dp_prev - dp);
/* Copy starting vert's edgeflag:
*/
new_vert->edgeflag = vert_prev->edgeflag;
+ *new_edge = *edge_prev;
}
}
vert_prev = vert;
+ edge_prev = edge;
dp_prev = dp;
}
+ /* swap in/out lists */
{
struct vertex_header **tmp = inlist;
inlist = outlist;
outlist = tmp;
n = outcount;
}
- }
-
- /* If flat-shading, copy color to new provoking vertex.
- */
- if (clipper->flat && inlist[0] != header->v[2]) {
- if (1) {
- inlist[0] = dup_vert(stage, inlist[0], tmpnr++);
+ {
+ boolean *tmp = inEdges;
+ inEdges = outEdges;
+ outEdges = tmp;
}
- copy_colors(stage, inlist[0], header->v[2]);
}
-
-
- /* Emit the polygon as triangles to the setup stage:
+ /* If flat-shading, copy provoking vertex color to polygon vertex[0]
*/
- if (n >= 3)
- emit_poly( stage, inlist, n, header );
+ if (n >= 3) {
+ if (clipper->flat) {
+ 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]);
+ }
+ }
+ else {
+ if (inlist[0] != header->v[2]) {
+ 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[2]);
+ }
+ }
+ }
+
+ /* Emit the polygon as triangles to the setup stage:
+ */
+ emit_poly( stage, inlist, inEdges, n, header );
+ }
}
struct prim_header *header,
unsigned clipmask )
{
- const struct clipper *clipper = clipper_stage( stage );
+ const struct clip_stage *clipper = clip_stage( stage );
struct vertex_header *v0 = header->v[0];
struct vertex_header *v1 = header->v[1];
const float *pos0 = v0->clip;
}
}
+
/* Update state. Could further delay this until we hit the first
* primitive that really requires clipping.
*/
static void
clip_init_state( struct draw_stage *stage )
{
- struct clipper *clipper = clipper_stage( stage );
+ struct clip_stage *clipper = clip_stage( stage );
clipper->flat = stage->draw->rasterizer->flatshade ? TRUE : FALSE;
*/
struct draw_stage *draw_clip_stage( struct draw_context *draw )
{
- struct clipper *clipper = CALLOC_STRUCT(clipper);
+ struct clip_stage *clipper = CALLOC_STRUCT(clip_stage);
if (clipper == NULL)
goto fail;
- if (!draw_alloc_temp_verts( &clipper->stage, MAX_CLIPPED_VERTICES+1 ))
- goto fail;
-
clipper->stage.draw = draw;
clipper->stage.name = "clipper";
clipper->stage.point = clip_point;
clipper->plane = draw->plane;
+ if (!draw_alloc_temp_verts( &clipper->stage, MAX_CLIPPED_VERTICES+1 ))
+ goto fail;
+
return &clipper->stage;
fail:
projects / mesa.git / blobdiff