glamor: Extract the streamed vertex data code used by Render.

We should be uploading any vertex data using this kind of upload
style, since it saves a bunch of extra copies of our vertex data.

v2:
  - Add a simple comment about what the function does.
  - Use get_vbo_space()'s return in trapezoids, instead of dereffing
    glamor_priv->vb (by Markus Wick).
  - Fix the double-unmapping by moving put_vbo_space() outside of
    flush_composite_rects().
  - Remove the rest of the composite_vbo_offset usage, and just always
    use get_vbo_space()'s return value.
v3:
  - Fix failure to put_vbo_space in traps when no prims were
    generated.
  - Unbind the VBO from put_vbo_space().  Keeps callers from
    forgetting to do so.
v4:
  - Split out some changes into the previous 3 commits while trying to
    track down a regression.
  - Fix regression due to rebase fail where glamor_priv->vbo_offset
    wasn't incremented.
v5:
  - Fix GLES2 VBO sizing.
  - Add a comment about resize behavior.
  - Move glamor_vbo.c init code to glamor_vbo.c from
    glamor_render.c. (Derived from Markus's changes, but the GLES2 fix
    dropped almost all of the code in the functions).
v6:
  - Drop the initial BufferData on GLES2 (it happens at put() time).
  - Don't forget to set vbo_offset to the size on GLES2.
  - Use char * instead of void * in the cast to return the vbo_offset.
  - Resize the default FBO to 512kb, to be similar to previous
    behavior.  +1.66124% +/- 0.284223% (n=679) on aa10text.

Signed-off-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Markus Wick <markus at selfnet.de>

1 files changed, 137 insertions, 0 deletions

diff --git a/glamor/glamor_vbo.c b/glamor/glamor_vbo.c
new file mode 100644
index 000000000..78c9033f6
--- /dev/null
+++ b/glamor/glamor_vbo.c
@@ -0,0 +1,137 @@
+/*
+ * Copyright © 2014 Intel Corporation
+ *
+ * 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.
+ */
+
+/**
+ * @file glamor_vbo.c
+ *
+ * Helpers for managing streamed vertex bufffers used in glamor.
+ */
+
+#include "glamor_priv.h"
+
+/** Default size of the VBO, in bytes.
+ *
+ * If a single request is larger than this size, we'll resize the VBO
+ * and return an appropriate mapping, but we'll resize back down after
+ * that to avoid hogging that memory forever.  We don't anticipate
+ * normal usage actually requiring larger VBO sizes.
+ */
+#define GLAMOR_VBO_SIZE (512 * 1024)
+
+/**
+ * Returns a pointer to @size bytes of VBO storage, which should be
+ * accessed by the GL using vbo_offset within the VBO.
+ */
+void *
+glamor_get_vbo_space(ScreenPtr screen, unsigned size, char **vbo_offset)
+{
+    glamor_screen_private *glamor_priv = glamor_get_screen_private(screen);
+    void *data;
+
+    glamor_get_context(glamor_priv);
+
+    glBindBuffer(GL_ARRAY_BUFFER, glamor_priv->vbo);
+
+    if (glamor_priv->gl_flavor == GLAMOR_GL_DESKTOP) {
+        if (glamor_priv->vbo_size < glamor_priv->vbo_offset + size) {
+            glamor_priv->vbo_size = MAX(GLAMOR_VBO_SIZE, size);
+            glamor_priv->vbo_offset = 0;
+            glBufferData(GL_ARRAY_BUFFER,
+                         glamor_priv->vbo_size, NULL, GL_STREAM_DRAW);
+        }
+
+        data = glMapBufferRange(GL_ARRAY_BUFFER,
+                                glamor_priv->vbo_offset,
+                                size,
+                                GL_MAP_WRITE_BIT |
+                                GL_MAP_UNSYNCHRONIZED_BIT |
+                                GL_MAP_INVALIDATE_RANGE_BIT);
+        assert(data != NULL);
+        *vbo_offset = (char *)(uintptr_t)glamor_priv->vbo_offset;
+        glamor_priv->vbo_offset += size;
+    } else {
+        /* Return a pointer to the statically allocated non-VBO
+         * memory. We'll upload it through glBufferData() later.
+         */
+        if (glamor_priv->vbo_size < size) {
+            glamor_priv->vbo_size = MAX(GLAMOR_VBO_SIZE, size);
+            free(glamor_priv->vb);
+            glamor_priv->vb = XNFalloc(size);
+        }
+        *vbo_offset = NULL;
+        /* We point to the start of glamor_priv->vb every time, and
+         * the vbo_offset determines the size of the glBufferData().
+         */
+        glamor_priv->vbo_offset = size;
+        data = glamor_priv->vb;
+    }
+
+    glamor_put_context(glamor_priv);
+
+    return data;
+}
+
+void
+glamor_put_vbo_space(ScreenPtr screen)
+{
+    glamor_screen_private *glamor_priv = glamor_get_screen_private(screen);
+
+    glamor_get_context(glamor_priv);
+
+    if (glamor_priv->gl_flavor == GLAMOR_GL_DESKTOP) {
+        glUnmapBuffer(GL_ARRAY_BUFFER);
+    } else {
+        glBufferData(GL_ARRAY_BUFFER, glamor_priv->vbo_offset,
+                     glamor_priv->vb, GL_DYNAMIC_DRAW);
+    }
+
+    glBindBuffer(GL_ARRAY_BUFFER, 0);
+
+    glamor_put_context(glamor_priv);
+}
+
+void
+glamor_init_vbo(ScreenPtr screen)
+{
+    glamor_screen_private *glamor_priv = glamor_get_screen_private(screen);
+
+    glamor_get_context(glamor_priv);
+
+    glGenBuffers(1, &glamor_priv->vbo);
+
+    glamor_put_context(glamor_priv);
+}
+
+void
+glamor_fini_vbo(ScreenPtr screen)
+{
+    glamor_screen_private *glamor_priv = glamor_get_screen_private(screen);
+
+    glamor_get_context(glamor_priv);
+
+    glDeleteBuffers(1, &glamor_priv->vbo);
+    if (glamor_priv->gl_flavor != GLAMOR_GL_DESKTOP)
+        free(glamor_priv->vb);
+
+    glamor_put_context(glamor_priv);
+}