vo_opengl: support external user hooks

This allows users to add their own near-arbitrary hooks to the vo_opengl
processing pipeline, greatly enhancing the flexibility of user shaders.
This enables, among other things, user shaders such as CrossBilateral,
SuperRes, LumaSharpen and many more.

To make parsing the user shaders easier, shaders are now loaded as
bstrs, and the hooks are set up during video reconfig instead of on
every single frame.

1 files changed, 42 insertions, 0 deletions

diff --git a/video/out/opengl/user_shaders.h b/video/out/opengl/user_shaders.h
new file mode 100644
index 0000000000..051dcaaa58
--- /dev/null
+++ b/video/out/opengl/user_shaders.h
@@ -0,0 +1,42 @@
+/*
+ * 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/>.
+ */
+
+#ifndef MP_GL_USER_SHADERS_H
+#define MP_GL_USER_SHADERS_H
+
+#include "common.h"
+#include "utils.h"
+
+#define SHADER_API 1
+#define SHADER_MAX_HOOKS 16
+#define SHADER_MAX_BINDS 6
+
+struct gl_user_shader {
+    struct bstr hook_tex[SHADER_MAX_HOOKS];
+    struct bstr bind_tex[SHADER_MAX_BINDS];
+    struct bstr save_tex;
+    struct bstr pass_body;
+    struct gl_transform transform;
+    int components;
+};
+
+// Parse the next shader pass from 'body'. Returns false if the end of the
+// string was reached
+bool parse_user_shader_pass(struct mp_log *log, struct bstr *body,
+                            struct gl_user_shader *out);
+
+#endif