util: add a couple primitive restart helper functions

The first function translates prim restart indexes to be 0xffff or
0xffffffff.

The second splits indexed primitives with restart indexes into sub-
primitives without restart indexes.

Reviewed-by: Roland Scheidegger <[email protected]>

2 files changed, 329 insertions, 0 deletions

diff --git a/src/gallium/auxiliary/util/u_prim_restart.c b/src/gallium/auxiliary/util/u_prim_restart.c
new file mode 100644
index 00000000000..a4d7c1433d9
--- /dev/null
+++ b/src/gallium/auxiliary/util/u_prim_restart.c
@@ -0,0 +1,267 @@
+/*
+ * Copyright 2014 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.
+ */
+
+
+
+#include "u_inlines.h"
+#include "u_memory.h"
+#include "u_prim_restart.h"
+
+
+/**
+ * Translate an index buffer for primitive restart.
+ * Create a new index buffer which is a copy of the original index buffer
+ * except that instances of 'restart_index' are converted to 0xffff or
+ * 0xffffffff.
+ * Also, index buffers using 1-byte indexes are converted to 2-byte indexes.
+ */
+enum pipe_error
+util_translate_prim_restart_ib(struct pipe_context *context,
+                               struct pipe_index_buffer *src_buffer,
+                               struct pipe_resource **dst_buffer,
+                               unsigned num_indexes,
+                               unsigned restart_index)
+{
+   struct pipe_screen *screen = context->screen;
+   struct pipe_transfer *src_transfer = NULL, *dst_transfer = NULL;
+   void *src_map = NULL, *dst_map = NULL;
+   const unsigned src_index_size = src_buffer->index_size;
+   unsigned dst_index_size;
+
+   /* 1-byte indexes are converted to 2-byte indexes, 4-byte stays 4-byte */
+   dst_index_size = MAX2(2, src_buffer->index_size);
+   assert(dst_index_size == 2 || dst_index_size == 4);
+
+   /* no user buffers for now */
+   assert(src_buffer->user_buffer == NULL);
+
+   /* Create new index buffer */
+   *dst_buffer = pipe_buffer_create(screen, PIPE_BIND_INDEX_BUFFER,
+                                    PIPE_USAGE_STREAM,
+                                    num_indexes * dst_index_size);
+   if (!*dst_buffer)
+      goto error;
+
+   /* Map new / dest index buffer */
+   dst_map = pipe_buffer_map(context, *dst_buffer,
+                             PIPE_TRANSFER_WRITE, &dst_transfer);
+   if (!dst_map)
+      goto error;
+
+   /* Map original / src index buffer */
+   src_map = pipe_buffer_map_range(context, src_buffer->buffer,
+                                   src_buffer->offset,
+                                   num_indexes * src_index_size,
+                                   PIPE_TRANSFER_READ,
+                                   &src_transfer);
+   if (!src_map)
+      goto error;
+
+   if (src_index_size == 1 && dst_index_size == 2) {
+      uint8_t *src = (uint8_t *) src_map;
+      uint16_t *dst = (uint16_t *) dst_map;
+      unsigned i;
+      for (i = 0; i < num_indexes; i++) {
+         dst[i] = (src[i] == restart_index) ? 0xffff : src[i];
+      }
+   }
+   else if (src_index_size == 2 && dst_index_size == 2) {
+      uint16_t *src = (uint16_t *) src_map;
+      uint16_t *dst = (uint16_t *) dst_map;
+      unsigned i;
+      for (i = 0; i < num_indexes; i++) {
+         dst[i] = (src[i] == restart_index) ? 0xffff : src[i];
+      }
+   }
+   else {
+      uint32_t *src = (uint32_t *) src_map;
+      uint32_t *dst = (uint32_t *) dst_map;
+      unsigned i;
+      assert(src_index_size == 4);
+      assert(dst_index_size == 4);
+      for (i = 0; i < num_indexes; i++) {
+         dst[i] = (src[i] == restart_index) ? 0xffffffff : src[i];
+      }
+   }
+
+   pipe_buffer_unmap(context, src_transfer);
+   pipe_buffer_unmap(context, dst_transfer);
+
+   return PIPE_OK;
+
+error:
+   if (src_transfer)
+      pipe_buffer_unmap(context, src_transfer);
+   if (dst_transfer)
+      pipe_buffer_unmap(context, dst_transfer);
+   if (*dst_buffer)
+      screen->resource_destroy(screen, *dst_buffer);
+   return PIPE_ERROR_OUT_OF_MEMORY;
+}
+
+
+/** Helper structs for util_draw_vbo_without_prim_restart() */
+
+struct range {
+   unsigned start, count;
+};
+
+struct range_info {
+   struct range *ranges;
+   unsigned count, max;
+};
+
+
+/**
+ * Helper function for util_draw_vbo_without_prim_restart()
+ * \return true for success, false if out of memory
+ */
+static boolean
+add_range(struct range_info *info, unsigned start, unsigned count)
+{
+   if (info->max == 0) {
+      info->max = 10;
+      info->ranges = MALLOC(info->max * sizeof(struct range));
+      if (!info->ranges) {
+         return FALSE;
+      }
+   }
+   else if (info->count == info->max) {
+      /* grow the ranges[] array */
+      info->ranges = REALLOC(info->ranges,
+                             info->max * sizeof(struct range),
+                             2 * info->max * sizeof(struct range));
+      if (!info->ranges) {
+         return FALSE;
+      }
+
+      info->max *= 2;
+   }
+
+   /* save the range */
+   info->ranges[info->count].start = start;
+   info->ranges[info->count].count = count;
+   info->count++;
+
+   return TRUE;
+}
+
+
+/**
+ * Implement primitive restart by breaking an indexed primitive into
+ * pieces which do not contain restart indexes.  Each piece is then
+ * drawn by calling pipe_context::draw_vbo().
+ * \return PIPE_OK if no error, an error code otherwise.
+ */
+enum pipe_error
+util_draw_vbo_without_prim_restart(struct pipe_context *context,
+                                   const struct pipe_index_buffer *ib,
+                                   const struct pipe_draw_info *info)
+{
+   const void *src_map;
+   struct range_info ranges = {0};
+   struct pipe_draw_info new_info;
+   struct pipe_transfer *src_transfer = NULL;
+   unsigned i, start, count;
+
+   assert(info->indexed);
+   assert(info->primitive_restart);
+
+   /* Get pointer to the index data */
+   if (ib->buffer) {
+      /* map the index buffer (only the range we need to scan) */
+      src_map = pipe_buffer_map_range(context, ib->buffer,
+                                      ib->offset + info->start * ib->index_size,
+                                      info->count * ib->index_size,
+                                      PIPE_TRANSFER_READ,
+                                      &src_transfer);
+      if (!src_map) {
+         return PIPE_ERROR_OUT_OF_MEMORY;
+      }
+   }
+   else {
+      if (!ib->user_buffer) {
+         debug_printf("User-space index buffer is null!");
+         return PIPE_ERROR_BAD_INPUT;
+      }
+      src_map = (const uint8_t *) ib->user_buffer
+         + ib->offset
+         + info->start * ib->index_size;
+   }
+
+#define SCAN_INDEXES(TYPE) \
+   for (i = 0; i <= info->count; i++) { \
+      if (i == info->count || \
+          ((const TYPE *) src_map)[i] == info->restart_index) { \
+         /* cut / restart */ \
+         if (count > 0) { \
+            if (!add_range(&ranges, info->start + start, count)) { \
+               if (src_transfer) \
+                  pipe_buffer_unmap(context, src_transfer); \
+               return PIPE_ERROR_OUT_OF_MEMORY; \
+            } \
+         } \
+         start = i + 1; \
+         count = 0; \
+      } \
+      else { \
+         count++; \
+      } \
+   }
+
+   start = info->start;
+   count = 0;
+   switch (ib->index_size) {
+   case 1:
+      SCAN_INDEXES(uint8_t);
+      break;
+   case 2:
+      SCAN_INDEXES(uint16_t);
+      break;
+   case 4:
+      SCAN_INDEXES(uint32_t);
+      break;
+   default:
+      assert(!"Bad index size");
+      return PIPE_ERROR_BAD_INPUT;
+   }
+
+   /* unmap index buffer */
+   if (src_transfer)
+      pipe_buffer_unmap(context, src_transfer);
+
+   /* draw ranges between the restart indexes */
+   new_info = *info;
+   new_info.primitive_restart = FALSE;
+   for (i = 0; i < ranges.count; i++) {
+      new_info.start = ranges.ranges[i].start;
+      new_info.count = ranges.ranges[i].count;
+      context->draw_vbo(context, &new_info);
+   }
+
+   FREE(ranges.ranges);
+
+   return PIPE_OK;
+}
diff --git a/src/gallium/auxiliary/util/u_prim_restart.h b/src/gallium/auxiliary/util/u_prim_restart.h
new file mode 100644
index 00000000000..1e98e0e1b22
--- /dev/null
+++ b/src/gallium/auxiliary/util/u_prim_restart.h
@@ -0,0 +1,62 @@
+/*
+ * Copyright 2014 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.
+ */
+
+
+#ifndef U_PRIM_RESTART_H
+#define U_PRIM_RESTART_H
+
+
+#include "pipe/p_defines.h"
+
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+
+struct pipe_context;
+struct pipe_draw_info;
+struct pipe_index_buffer;
+struct pipe_resource;
+
+
+enum pipe_error
+util_translate_prim_restart_ib(struct pipe_context *context,
+                               struct pipe_index_buffer *src_buffer,
+                               struct pipe_resource **dst_buffer,
+                               unsigned num_indexes,
+                               unsigned restart_index);
+
+enum pipe_error
+util_draw_vbo_without_prim_restart(struct pipe_context *context,
+                                   const struct pipe_index_buffer *ib,
+                                   const struct pipe_draw_info *info);
+
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif