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-rw-r--r--src/gallium/auxiliary/util/u_split_draw.c67
1 files changed, 67 insertions, 0 deletions
diff --git a/src/gallium/auxiliary/util/u_split_draw.c b/src/gallium/auxiliary/util/u_split_draw.c
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+/*
+ * 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, sublicense,
+ * 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 NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS 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 "pipe/p_defines.h"
+#include "util/u_debug.h"
+#include "util/u_split_draw.h"
+
+bool
+u_split_draw(const struct pipe_draw_info *info, uint32_t max_verts,
+ uint32_t *count, uint32_t *step)
+{
+ if (*count <= max_verts) {
+ *step = *count;
+ return false;
+ }
+
+ switch (info->mode) {
+ case PIPE_PRIM_POINTS:
+ *count = *step = max_verts;
+ break;
+ case PIPE_PRIM_LINES:
+ *count = *step = max_verts - (max_verts % 2);
+ break;
+ case PIPE_PRIM_LINE_STRIP:
+ *count = max_verts;
+ *step = max_verts - 1;
+ break;
+ case PIPE_PRIM_LINE_LOOP:
+ *count = max_verts;
+ *step = max_verts - 1;
+ debug_warn_once("unhandled line loop "
+ "looping behavior with "
+ ">max vert count\n");
+ break;
+ case PIPE_PRIM_TRIANGLES:
+ *count = *step = max_verts - (max_verts % 3);
+ break;
+ case PIPE_PRIM_TRIANGLE_STRIP:
+ *count = max_verts;
+ *step = max_verts - 2;
+ break;
+ default:
+ debug_warn_once("unhandled primitive "
+ "max vert count, truncating\n");
+ *count = *step = max_verts;
+ }
+
+ return true;
+}