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authorBrian <brian.paul@tungstengraphics.com>2007-09-06 17:03:54 -0600
committerBrian <brian.paul@tungstengraphics.com>2007-09-06 17:03:54 -0600
commit41ddd76b98e9e236a796f1bb9480ea0b2fb18010 (patch)
treede243a9a2475fea272655073932fcbdae5bb8dff
parent4c01d498fac14bba751dd87bff235efb5409dca9 (diff)
Initial work for post-transform vertex feedback buffers.
This will be used for: GL_NV_transform_feedback, or GL3 equivalent. RasterPos GL select/feedback modes
-rw-r--r--src/mesa/pipe/draw/draw_feedback.c247
1 files changed, 247 insertions, 0 deletions
diff --git a/src/mesa/pipe/draw/draw_feedback.c b/src/mesa/pipe/draw/draw_feedback.c
new file mode 100644
index 0000000000..2729f44dc6
--- /dev/null
+++ b/src/mesa/pipe/draw/draw_feedback.c
@@ -0,0 +1,247 @@
+/**************************************************************************
+ *
+ * Copyright 2007 Tungsten Graphics, Inc., Cedar Park, Texas.
+ * 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 TUNGSTEN GRAPHICS 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.
+ *
+ **************************************************************************/
+
+/**
+ * Primitive/vertex feedback (and/or discard) stage.
+ * Used to implement transformation feedback/streaming and other things
+ * which require a post-transformed vertex position (such as rasterpos,
+ * selection and feedback modes).
+ *
+ * Authors:
+ * Brian Paul
+ */
+
+
+#include "pipe/p_util.h"
+#include "draw_private.h"
+
+
+struct feedback_stage {
+ struct draw_stage stage; /**< base class */
+ uint num_prim_generated; /**< number of primitives received */
+ uint num_prim_emitted; /**< number of primitives fed back */
+ uint num_vert_emitted; /**< number of vertices fed back */
+ uint max_vert_emit; /**< max number of verts we can emit */
+ float *dest[PIPE_MAX_FEEDBACK_ATTRIBS]; /**< dests for vertex attribs */
+};
+
+
+
+/**
+ * Check if there's space to store 'numVerts' in the feedback buffer(s).
+ */
+static boolean
+check_space(const struct draw_stage *stage, uint numVerts)
+{
+ const struct feedback_stage *fs = (struct feedback_stage *) stage;
+ return fs->num_vert_emitted + numVerts <= fs->max_vert_emit;
+}
+
+
+/**
+ * Record the given vertex's attributes into the feedback buffer(s).
+ */
+static void
+feedback_vertex(struct draw_stage *stage, const struct vertex_header *vertex)
+{
+ struct feedback_stage *fs = (struct feedback_stage *) stage;
+ const struct pipe_feedback_state *feedback = &stage->draw->feedback;
+ const uint select = feedback->interleaved ? 0 : 1;
+ uint i;
+
+ /*
+ * Note: 'select' is either 0 or 1. By multiplying 'i' by 'select'
+ * we can either address output buffer 0 (for interleaving) or
+ * output buffer i (for non-interleaved).
+ */
+
+ for (i = 0; i < feedback->num_attribs; i++) {
+ const uint attr = feedback->attrib[i];
+ const float *src = attr ? vertex->data[attr] : vertex->clip;
+ const uint size = feedback->size[i];
+ float *dest = fs->dest[i * select];
+
+ switch (size) {
+ case 4:
+ dest[3] = src[3];
+ /* fall-through */
+ case 3:
+ dest[2] = src[2];
+ /* fall-through */
+ case 2:
+ dest[1] = src[1];
+ /* fall-through */
+ case 1:
+ dest[0] = src[0];
+ /* fall-through */
+ default:
+ ;
+ }
+ fs->dest[i * select] += size;
+ }
+
+ fs->num_vert_emitted++;
+}
+
+
+static void feedback_begin( struct draw_stage *stage )
+{
+ struct feedback_stage *fs = (struct feedback_stage *) stage;
+ const struct pipe_feedback_state *feedback = &stage->draw->feedback;
+
+ fs->num_prim_generated = 0;
+ fs->num_prim_emitted = 0;
+ fs->num_vert_emitted = 0;
+
+ assert(feedback->enabled);
+
+ /* Compute max_vert_emit, the max number of vertices we can emit.
+ * And, setup dest[] pointers.
+ */
+ if (stage->draw->feedback.interleaved) {
+ uint i, vertex_size = 0;
+ /* compute size of each interleaved vertex, in floats */
+ for (i = 0; i < feedback->num_attribs; i++) {
+ vertex_size += feedback->size[i];
+ }
+ /* compute max number of vertices we can feedback */
+ fs->max_vert_emit = stage->draw->mapped_feedback_buffer_size[0]
+ / sizeof(float) / vertex_size;
+
+ fs->dest[0] = (float *) stage->draw->mapped_feedback_buffer[0];
+ }
+ else {
+ uint i;
+ uint max = ~0;
+ for (i = 0; i < feedback->num_attribs; i++) {
+ uint n = stage->draw->mapped_feedback_buffer_size[i]
+ / sizeof(float) / feedback->size[i];
+ if (n < max)
+ max = n;
+ fs->dest[i] = (float *) stage->draw->mapped_feedback_buffer[i];
+ }
+ fs->max_vert_emit = max;
+ }
+
+ if (!feedback->discard)
+ stage->next->begin( stage->next );
+}
+
+
+static void feedback_tri( struct draw_stage *stage,
+ struct prim_header *header )
+{
+ struct feedback_stage *fs = (struct feedback_stage *) stage;
+
+ fs->num_prim_generated++;
+
+ if (stage->draw->feedback.enabled && check_space(stage, 3)) {
+ feedback_vertex(stage, header->v[0]);
+ feedback_vertex(stage, header->v[1]);
+ feedback_vertex(stage, header->v[2]);
+ fs->num_prim_emitted++;
+ }
+
+ if (!stage->draw->feedback.discard)
+ stage->next->tri( stage->next, header );
+}
+
+
+static void feedback_line( struct draw_stage *stage,
+ struct prim_header *header )
+{
+ struct feedback_stage *fs = (struct feedback_stage *) stage;
+
+ fs->num_prim_generated++;
+
+ if (stage->draw->feedback.enabled && check_space(stage, 2)) {
+ feedback_vertex(stage, header->v[0]);
+ feedback_vertex(stage, header->v[1]);
+ fs->num_prim_emitted++;
+ }
+
+ if (!stage->draw->feedback.discard)
+ stage->next->line( stage->next, header );
+}
+
+
+static void feedback_point( struct draw_stage *stage,
+ struct prim_header *header )
+{
+ struct feedback_stage *fs = (struct feedback_stage *) stage;
+
+ fs->num_prim_generated++;
+
+ if (stage->draw->feedback.enabled && check_space(stage, 1)) {
+ feedback_vertex(stage, header->v[0]);
+ fs->num_prim_emitted++;
+ }
+
+ if (!stage->draw->feedback.discard)
+ stage->next->point( stage->next, header );
+}
+
+
+static void feedback_end( struct draw_stage *stage )
+{
+
+ /* XXX Unmap the vertex feedback buffers so we can write to them */
+
+
+ if (!stage->draw->feedback.discard)
+ stage->next->end( stage->next );
+}
+
+
+
+static void feedback_reset_stipple_counter( struct draw_stage *stage )
+{
+ if (!stage->draw->feedback.discard)
+ stage->next->reset_stipple_counter( stage->next );
+}
+
+
+/**
+ * Create feedback drawing stage.
+ */
+struct draw_stage *draw_feedback_stage( struct draw_context *draw )
+{
+ struct feedback_stage *feedback = CALLOC_STRUCT(feedback_stage);
+
+ feedback->stage.draw = draw;
+ feedback->stage.next = NULL;
+ feedback->stage.begin = feedback_begin;
+ feedback->stage.point = feedback_point;
+ feedback->stage.line = feedback_line;
+ feedback->stage.tri = feedback_tri;
+ feedback->stage.end = feedback_end;
+ feedback->stage.reset_stipple_counter = feedback_reset_stipple_counter;
+
+ return &feedback->stage;
+}
+
+