vo_gpu: vulkan: initial implementation

This time based on ra/vo_gpu. 2017 is the year of the vulkan desktop!

Current problems / limitations / improvement opportunities:

1. The swapchain/flipping code violates the vulkan spec, by assuming
   that the presentation queue will be bounded (in cases where rendering
   is significantly faster than vsync). But apparently, there's simply
   no better way to do this right now, to the point where even the
   stupid cube.c examples from LunarG etc. do it wrong.
   (cf. https://github.com/KhronosGroup/Vulkan-Docs/issues/370)

2. The memory allocator could be improved. (This is a universal
   constant)

3. Could explore using push descriptors instead of descriptor sets,
   especially since we expect to switch descriptors semi-often for some
   passes (like interpolation). Probably won't make a difference, but
   the synchronization overhead might be a factor. Who knows.

4. Parallelism across frames / async transfer is not well-defined, we
   either need to use a better semaphore / command buffer strategy or a
   resource pooling layer to safely handle cross-frame parallelism.
   (That said, I gave resource pooling a try and was not happy with the
   result at all - so I'm still exploring the semaphore strategy)

5. We aggressively use pipeline barriers where events would offer a much
   more fine-grained synchronization mechanism. As a result of this, we
   might be suffering from GPU bubbles due to too-short dependencies on
   objects. (That said, I'm also exploring the use of semaphores as a an
   ordering tactic which would allow cross-frame time slicing in theory)

Some minor changes to the vo_gpu and infrastructure, but nothing
consequential.

NOTE: For safety, all use of asynchronous commands / multiple command
pools is currently disabled completely. There are some left-over relics
of this in the code (e.g. the distinction between dev_poll and
pool_poll), but that is kept in place mostly because this will be
re-extended in the future (vulkan rev 2).

The queue count is also currently capped to 1, because of the lack of
cross-frame semaphores means we need the implicit synchronization from
the same-queue semantics to guarantee a correct result.

1 files changed, 116 insertions, 0 deletions

diff --git a/video/out/vulkan/context_xlib.c b/video/out/vulkan/context_xlib.c
new file mode 100644
index 0000000000..2611fbb706
--- /dev/null
+++ b/video/out/vulkan/context_xlib.c
@@ -0,0 +1,116 @@
+/*
+ * This file is part of mpv.
+ *
+ * mpv is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * mpv is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with mpv.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "video/out/gpu/context.h"
+#include "video/out/x11_common.h"
+
+#include "common.h"
+#include "context.h"
+#include "utils.h"
+
+struct priv {
+    struct mpvk_ctx vk;
+};
+
+static void xlib_uninit(struct ra_ctx *ctx)
+{
+    struct priv *p = ctx->priv;
+
+    ra_vk_ctx_uninit(ctx);
+    mpvk_uninit(&p->vk);
+    vo_x11_uninit(ctx->vo);
+}
+
+static bool xlib_init(struct ra_ctx *ctx)
+{
+    struct priv *p = ctx->priv = talloc_zero(ctx, struct priv);
+    struct mpvk_ctx *vk = &p->vk;
+    int msgl = ctx->opts.probing ? MSGL_V : MSGL_ERR;
+
+    if (!vo_x11_init(ctx->vo))
+        goto error;
+
+    if (!vo_x11_create_vo_window(ctx->vo, NULL, "mpvk"))
+        goto error;
+
+    if (!mpvk_instance_init(vk, ctx->log, ctx->opts.debug))
+        goto error;
+
+    VkXlibSurfaceCreateInfoKHR xinfo = {
+         .sType = VK_STRUCTURE_TYPE_XLIB_SURFACE_CREATE_INFO_KHR,
+         .dpy = ctx->vo->x11->display,
+         .window = ctx->vo->x11->window,
+    };
+
+    VkResult res = vkCreateXlibSurfaceKHR(vk->inst, &xinfo, MPVK_ALLOCATOR,
+                                          &vk->surf);
+    if (res != VK_SUCCESS) {
+        MP_MSG(ctx, msgl, "Failed creating Xlib surface: %s\n", vk_err(res));
+        goto error;
+    }
+
+    if (!ra_vk_ctx_init(ctx, vk, VK_PRESENT_MODE_FIFO_KHR))
+        goto error;
+
+    return true;
+
+error:
+    xlib_uninit(ctx);
+    return false;
+}
+
+static bool resize(struct ra_ctx *ctx)
+{
+    return ra_vk_ctx_resize(ctx->swapchain, ctx->vo->dwidth, ctx->vo->dheight);
+}
+
+static bool xlib_reconfig(struct ra_ctx *ctx)
+{
+    vo_x11_config_vo_window(ctx->vo);
+    return resize(ctx);
+}
+
+static int xlib_control(struct ra_ctx *ctx, int *events, int request, void *arg)
+{
+    int ret = vo_x11_control(ctx->vo, events, request, arg);
+    if (*events & VO_EVENT_RESIZE) {
+        if (!resize(ctx))
+            return VO_ERROR;
+    }
+    return ret;
+}
+
+static void xlib_wakeup(struct ra_ctx *ctx)
+{
+    vo_x11_wakeup(ctx->vo);
+}
+
+static void xlib_wait_events(struct ra_ctx *ctx, int64_t until_time_us)
+{
+    vo_x11_wait_events(ctx->vo, until_time_us);
+}
+
+const struct ra_ctx_fns ra_ctx_vulkan_xlib = {
+    .type           = "vulkan",
+    .name           = "x11",
+    .reconfig       = xlib_reconfig,
+    .control        = xlib_control,
+    .wakeup         = xlib_wakeup,
+    .wait_events    = xlib_wait_events,
+    .init           = xlib_init,
+    .uninit         = xlib_uninit,
+};