vo_opengl: make PBOs work on GLES 3.x

For some reason, GLES has no glMapBuffer, only glMapBufferRange.

GLES 2 has no buffer mapping at all, and GL 2.1 does not always have
glMapBufferRange. On those PBOs remain unsupported (there's no reason to
care about GL 2.1 without the extension).

This doesn't actually work on ANGLE, and I have no idea why. (There are
artifacts on OSD, as if parts of the OSD data weren't copied.) It works
on desktop OpenGL and at least 1 other ES 3 implementation. Don't enable
it on ANGLE, I guess.

4 files changed, 24 insertions, 10 deletions

diff --git a/video/out/opengl/common.c b/video/out/opengl/common.c
index 6287fc488b..7121522f4b 100644
--- a/video/out/opengl/common.c
+++ b/video/out/opengl/common.c
@@ -147,13 +147,22 @@ static const struct gl_functions gl_functions[] = {
         .provides = MPGL_CAP_ROW_LENGTH | MPGL_CAP_1D_TEX,
         .functions = (const struct gl_function[]) {
             DEF_FN(GetTexLevelParameteriv),
-            DEF_FN(MapBuffer),
             DEF_FN(ReadBuffer),
             DEF_FN(TexImage1D),
             DEF_FN(UnmapBuffer),
             {0}
         },
     },
+    // GL 2.1 has this as extension only.
+    {
+        .ver_exclude = 300,
+        .ver_es_exclude = 300,
+        .extension = "GL_ARB_map_buffer_range",
+        .functions = (const struct gl_function[]) {
+            DEF_FN(MapBufferRange),
+            {0}
+        },
+    },
     // GL 3.0+ and ES 3.x core only functions.
     {
         .ver_core = 300,
@@ -162,6 +171,7 @@ static const struct gl_functions gl_functions[] = {
             DEF_FN(BindBufferBase),
             DEF_FN(BlitFramebuffer),
             DEF_FN(GetStringi),
+            DEF_FN(MapBufferRange),
             // for ES 3.0
             DEF_FN(ReadBuffer),
             DEF_FN(UnmapBuffer),
diff --git a/video/out/opengl/common.h b/video/out/opengl/common.h
index c55f1654fc..84c27dfea0 100644
--- a/video/out/opengl/common.h
+++ b/video/out/opengl/common.h
@@ -126,7 +126,8 @@ struct GL {
     void (GLAPIENTRY *DeleteBuffers)(GLsizei, const GLuint *);
     void (GLAPIENTRY *BindBuffer)(GLenum, GLuint);
     void (GLAPIENTRY *BindBufferBase)(GLenum, GLuint, GLuint);
-    GLvoid * (GLAPIENTRY * MapBuffer)(GLenum, GLenum);
+    GLvoid * (GLAPIENTRY *MapBufferRange)(GLenum, GLintptr, GLsizeiptr,
+                                          GLbitfield);
     GLboolean (GLAPIENTRY *UnmapBuffer)(GLenum);
     void (GLAPIENTRY *BufferData)(GLenum, intptr_t, const GLvoid *, GLenum);
     void (GLAPIENTRY *ActiveTexture)(GLenum);
diff --git a/video/out/opengl/osd.c b/video/out/opengl/osd.c
index bf03d34e90..d8059166be 100644
--- a/video/out/opengl/osd.c
+++ b/video/out/opengl/osd.c
@@ -139,18 +139,19 @@ static bool upload_pbo(struct mpgl_osd *ctx, struct mpgl_osd_part *osd,
     GL *gl = ctx->gl;
     bool success = true;
     const struct gl_format *fmt = ctx->fmt_table[imgs->format];
-    int pix_stride = gl_bytes_per_pixel(fmt->format, fmt->type);
+    size_t pix_stride = gl_bytes_per_pixel(fmt->format, fmt->type);
+    size_t buffer_size = pix_stride * osd->h * osd->w;
 
     if (!osd->buffer) {
         gl->GenBuffers(1, &osd->buffer);
         gl->BindBuffer(GL_PIXEL_UNPACK_BUFFER, osd->buffer);
-        gl->BufferData(GL_PIXEL_UNPACK_BUFFER, osd->w * osd->h * pix_stride,
-                        NULL, GL_DYNAMIC_COPY);
+        gl->BufferData(GL_PIXEL_UNPACK_BUFFER, buffer_size, NULL, GL_DYNAMIC_COPY);
         gl->BindBuffer(GL_PIXEL_UNPACK_BUFFER, 0);
     }
 
     gl->BindBuffer(GL_PIXEL_UNPACK_BUFFER, osd->buffer);
-    char *data = gl->MapBuffer(GL_PIXEL_UNPACK_BUFFER, GL_WRITE_ONLY);
+    char *data = gl->MapBufferRange(GL_PIXEL_UNPACK_BUFFER, 0, buffer_size,
+                                    GL_MAP_WRITE_BIT | GL_MAP_INVALIDATE_BUFFER_BIT);
     if (!data) {
         success = false;
     } else {
diff --git a/video/out/opengl/video.c b/video/out/opengl/video.c
index bebe1373d6..edf7c7d1f6 100644
--- a/video/out/opengl/video.c
+++ b/video/out/opengl/video.c
@@ -2870,15 +2870,17 @@ static bool map_image(struct gl_video *p, struct mp_image *mpi)
     for (int n = 0; n < p->plane_count; n++) {
         struct texplane *plane = &vimg->planes[n];
         mpi->stride[n] = mp_image_plane_w(mpi, n) * p->image_desc.bytes[n];
+        size_t buffer_size = mp_image_plane_h(mpi, n) * mpi->stride[n];
         if (!plane->gl_buffer) {
             gl->GenBuffers(1, &plane->gl_buffer);
             gl->BindBuffer(GL_PIXEL_UNPACK_BUFFER, plane->gl_buffer);
-            size_t buffer_size = mp_image_plane_h(mpi, n) * mpi->stride[n];
             gl->BufferData(GL_PIXEL_UNPACK_BUFFER, buffer_size,
                            NULL, GL_DYNAMIC_DRAW);
         }
         gl->BindBuffer(GL_PIXEL_UNPACK_BUFFER, plane->gl_buffer);
-        mpi->planes[n] = gl->MapBuffer(GL_PIXEL_UNPACK_BUFFER, GL_WRITE_ONLY);
+        mpi->planes[n] = gl->MapBufferRange(GL_PIXEL_UNPACK_BUFFER, 0,
+                                            buffer_size, GL_MAP_WRITE_BIT |
+                                                GL_MAP_INVALIDATE_BUFFER_BIT);
         gl->BindBuffer(GL_PIXEL_UNPACK_BUFFER, 0);
         if (!mpi->planes[n]) {
             unmap_image(p, mpi);
@@ -3042,9 +3044,9 @@ static void check_gl_features(struct gl_video *p)
         }
     }
 
-    if (gl->es && p->opts.pbo) {
+    if (!gl->MapBufferRange && p->opts.pbo) {
         p->opts.pbo = 0;
-        MP_WARN(p, "Disabling PBOs (GLES unsupported).\n");
+        MP_WARN(p, "Disabling PBOs (GL2.1/GLES2 unsupported).\n");
     }
 
     p->forced_dumb_mode = p->opts.dumb_mode || !have_fbo || !have_texrg;