vo_opengl: refactor shader generation (part 1)

The basic idea is to use dynamically generated shaders instead of a
single monolithic file + a ton of ifdefs. Instead of having to setup
every aspect of it separately (like compiling shaders, setting uniforms,
perfoming the actual rendering steps, the GLSL parts), we generate the
GLSL on the fly, and perform the rendering at the same time. The GLSL
is regenerated every frame, but the actual compiled OpenGL-level shaders
are cached, which makes it fast again. Almost all logic can be in a
single place.

The new code is significantly more flexible, which allows us to improve
the code clarity, performance and add more features easily.

This commit is incomplete. It drops almost all previous code, and
readds only the most important things (some of them actually buggy).
The next commit will complete it - it's separate to preserve authorship
information.

1 files changed, 8 insertions, 31 deletions

diff --git a/video/out/gl_osd.h b/video/out/gl_osd.h
index 5c34911e22..0acd200ab4 100644
--- a/video/out/gl_osd.h
+++ b/video/out/gl_osd.h
@@ -7,38 +7,15 @@
 #include "gl_utils.h"
 #include "sub/osd.h"
 
-struct mpgl_osd_part {
-    enum sub_bitmap_format format;
-    int bitmap_id, bitmap_pos_id;
-    GLuint texture;
-    int w, h;
-    GLuint buffer;
-    int num_vertices;
-    void *vertices;
-    struct bitmap_packer *packer;
-};
-
-struct mpgl_osd {
-    struct mp_log *log;
-    struct osd_state *osd;
-    GL *gl;
-    bool use_pbo;
-    bool scaled;
-    struct mpgl_osd_part *parts[MAX_OSD_PARTS];
-    const struct osd_fmt_entry *fmt_table;
-    bool formats[SUBBITMAP_COUNT];
-    struct gl_vao vao;
-    GLuint *programs; // SUBBITMAP_COUNT elements
-    // temporary
-    float offset[2];
-    void *scratch;
-};
-
-struct mpgl_osd *mpgl_osd_init(GL *gl, struct mp_log *log, struct osd_state *osd,
-                               GLuint *programs);
+struct mpgl_osd *mpgl_osd_init(GL *gl, struct mp_log *log, struct osd_state *osd);
 void mpgl_osd_destroy(struct mpgl_osd *ctx);
 
-void mpgl_osd_draw(struct mpgl_osd *ctx, struct mp_osd_res res, double pts,
-                   int stereo_mode);
+void mpgl_osd_set_options(struct mpgl_osd *ctx, bool pbo);
+
+void mpgl_osd_generate(struct mpgl_osd *ctx, struct mp_osd_res res, double pts,
+                       int stereo_mode);
+enum sub_bitmap_format mpgl_osd_get_part_format(struct mpgl_osd *ctx, int index);
+struct gl_vao *mpgl_osd_get_vao(struct mpgl_osd *ctx);
+void mpgl_osd_draw_part(struct mpgl_osd *ctx, int vp_w, int vp_h, int index);
 
 #endif