vo_opengl: start work on rendering API abstraction

This starts work on moving OpenGL-specific code out of the general
renderer code, so that we can support other other GPU APIs. This is in
a very early stage and it's only a proof of concept. It's unknown
whether this will succeed or result in other backends.

For now, the GL rendering API ("ra") and its only provider (ra_gl) does
texture creation/upload/destruction only. And it's used for the main
video texture only. All other code is still hardcoded to GL.

There is some duplication with ra_format and gl_format handling. In the
end, only the ra variants will be needed (plus the gl_format table of
course). For now, this is simpler, because for some reason lots of hwdec
code still requires the GL variants, and would have to be updated to
use the ra ones.

Currently, the video.c code accesses private ra_gl fields. In the end,
it should not do that of course, and it would not include ra_gl.h.

Probably adds bugs, but you can keep them.

1 files changed, 290 insertions, 0 deletions

diff --git a/video/out/opengl/ra_gl.c b/video/out/opengl/ra_gl.c
new file mode 100644
index 0000000000..bf926a197e
--- /dev/null
+++ b/video/out/opengl/ra_gl.c
@@ -0,0 +1,290 @@
+#include "formats.h"
+
+#include "ra_gl.h"
+
+static struct ra_fns ra_fns_gl;
+
+int ra_init_gl(struct ra *ra, GL *gl)
+{
+    if (gl->version < 210 && gl->es < 200) {
+        MP_ERR(ra, "At least OpenGL 2.1 or OpenGL ES 2.0 required.\n");
+        return -1;
+    }
+
+    struct ra_gl *p = ra->priv = talloc_zero(NULL, struct ra_gl);
+    p->gl = gl;
+
+    ra->fns = &ra_fns_gl;
+    ra->caps = 0;
+    if (gl->mpgl_caps & MPGL_CAP_1D_TEX)
+        ra->caps |= RA_CAP_TEX_1D;
+    if (gl->mpgl_caps & MPGL_CAP_3D_TEX)
+        ra->caps |= RA_CAP_TEX_3D;
+
+    int gl_fmt_features = gl_format_feature_flags(gl);
+    int depth16 = gl_determine_16bit_tex_depth(gl);
+
+    for (int n = 0; gl_formats[n].internal_format; n++) {
+        const struct gl_format *gl_fmt = &gl_formats[n];
+
+        if (!(gl_fmt->flags & gl_fmt_features))
+            continue;
+
+        struct ra_format *fmt = talloc_zero(ra, struct ra_format);
+        *fmt = (struct ra_format){
+            .name           = gl_fmt->name,
+            .priv           = (void *)gl_fmt,
+            .ctype          = gl_format_type(gl_fmt),
+            .num_components = gl_format_components(gl_fmt->format),
+            .pixel_size     = gl_bytes_per_pixel(gl_fmt->format, gl_fmt->type),
+            .luminance_alpha = gl_fmt->format == GL_LUMINANCE_ALPHA,
+            .linear_filter  = gl_fmt->flags & F_TF,
+            .renderable     = gl_fmt->flags & F_CR,
+        };
+
+        int csize = gl_component_size(gl_fmt->type) * 8;
+        int depth = csize;
+        if (fmt->ctype == RA_CTYPE_UNORM)
+            depth = MPMIN(csize, depth16); // naive/approximate
+        if (gl_fmt->flags & F_F16) {
+            depth = 16;
+            csize = 32; // always upload as GL_FLOAT (simpler for us)
+        }
+
+        for (int i = 0; i < fmt->num_components; i++) {
+            fmt->component_size[i] = csize;
+            fmt->component_depth[i] = depth;
+        }
+
+        // Special formats for which OpenGL happens to have direct support.
+        if (strcmp(fmt->name, "rgb565") == 0) {
+            fmt->special_imgfmt = IMGFMT_RGB565;
+            struct ra_imgfmt_desc *desc = talloc_zero(fmt, struct ra_imgfmt_desc);
+            fmt->special_imgfmt_desc = desc;
+            desc->num_planes = 1;
+            desc->planes[0] = fmt;
+            for (int i = 0; i < 3; i++)
+                desc->components[0][i] = i + 1;
+            desc->chroma_w = desc->chroma_h = 1;
+        }
+        if (strcmp(fmt->name, "ashit") == 0) {
+            fmt->special_imgfmt = IMGFMT_UYVY;
+            struct ra_imgfmt_desc *desc = talloc_zero(fmt, struct ra_imgfmt_desc);
+            fmt->special_imgfmt_desc = desc;
+            desc->num_planes = 1;
+            desc->planes[0] = fmt;
+            desc->components[0][0] = 3;
+            desc->components[0][1] = 1;
+            desc->components[0][2] = 2;
+            desc->chroma_w = desc->chroma_h = 1;
+        }
+
+        MP_TARRAY_APPEND(ra, ra->formats, ra->num_formats, fmt);
+    }
+
+    gl->Disable(GL_DITHER);
+
+    return 0;
+}
+
+static void gl_destroy(struct ra *ra)
+{
+    talloc_free(ra->priv);
+}
+
+static void gl_tex_destroy(struct ra *ra, struct ra_tex *tex)
+{
+    struct ra_gl *p = ra->priv;
+    struct ra_tex_gl *tex_gl = tex->priv;
+
+    p->gl->DeleteTextures(1, &tex_gl->texture);
+    gl_pbo_upload_uninit(&tex_gl->pbo);
+    talloc_free(tex_gl);
+    talloc_free(tex);
+}
+
+static struct ra_tex *gl_tex_create(struct ra *ra,
+                                    const struct ra_tex_params *params)
+{
+    struct ra_gl *p = ra->priv;
+    GL *gl = p->gl;
+
+    struct ra_tex *tex = talloc_zero(NULL, struct ra_tex);
+    tex->params = *params;
+    struct ra_tex_gl *tex_gl = tex->priv = talloc_zero(NULL, struct ra_tex_gl);
+
+    const struct gl_format *fmt = params->format->priv;
+    tex_gl->internal_format = fmt->internal_format;
+    tex_gl->format = fmt->format;
+    tex_gl->type = fmt->type;
+    switch (params->dimensions) {
+    case 1: tex_gl->target = GL_TEXTURE_1D; break;
+    case 2: tex_gl->target = GL_TEXTURE_2D; break;
+    case 3: tex_gl->target = GL_TEXTURE_3D; break;
+    default: abort();
+    }
+    if (params->non_normalized) {
+        assert(params->dimensions == 2);
+        tex_gl->target = GL_TEXTURE_RECTANGLE;
+    }
+
+    gl->GenTextures(1, &tex_gl->texture);
+    gl->BindTexture(tex_gl->target, tex_gl->texture);
+
+    GLint filter = params->src_linear ? GL_LINEAR : GL_NEAREST;
+    GLint wrap = params->src_repeat ? GL_REPEAT : GL_CLAMP_TO_EDGE;
+    gl->TexParameteri(tex_gl->target, GL_TEXTURE_MIN_FILTER, filter);
+    gl->TexParameteri(tex_gl->target, GL_TEXTURE_MAG_FILTER, filter);
+    gl->TexParameteri(tex_gl->target, GL_TEXTURE_WRAP_S, wrap);
+    if (params->dimensions > 1)
+        gl->TexParameteri(tex_gl->target, GL_TEXTURE_WRAP_T, wrap);
+    if (params->dimensions > 2)
+        gl->TexParameteri(tex_gl->target, GL_TEXTURE_WRAP_R, wrap);
+
+    switch (params->dimensions) {
+    case 1:
+        gl->TexImage1D(tex_gl->target, 0, tex_gl->internal_format, params->w,
+                       0, tex_gl->format, tex_gl->type, NULL);
+        break;
+    case 2:
+        gl->TexImage2D(tex_gl->target, 0, tex_gl->internal_format, params->w,
+                       params->h, 0, tex_gl->format, tex_gl->type, NULL);
+        break;
+    case 3:
+        gl->TexImage3D(tex_gl->target, 0, tex_gl->internal_format, params->w,
+                       params->h, params->d, 0, tex_gl->format, tex_gl->type,
+                       NULL);
+        break;
+    }
+
+    gl->BindTexture(tex_gl->target, 0);
+
+    return tex;
+}
+
+static void gl_tex_upload(struct ra *ra, struct ra_tex *tex,
+                         const void *src, ptrdiff_t stride,
+                         struct ra_mapped_buffer *buf)
+{
+    struct ra_gl *p = ra->priv;
+    GL *gl = p->gl;
+    struct ra_tex_gl *tex_gl = tex->priv;
+    struct ra_mapped_buffer_gl *buf_gl = NULL;
+
+    if (buf) {
+        buf_gl = buf->priv;
+        gl->BindBuffer(GL_PIXEL_UNPACK_BUFFER, buf_gl->pbo);
+        src = (void *)((uintptr_t)src - (uintptr_t)buf->data);
+    }
+
+    gl->BindTexture(tex_gl->target, tex_gl->texture);
+
+    switch (tex->params.dimensions) {
+    case 1:
+        gl->TexImage1D(tex_gl->target, 0, tex_gl->internal_format,
+                       tex->params.w, 0, tex_gl->format, tex_gl->type, src);
+        break;
+    case 2:
+        gl_pbo_upload_tex(&tex_gl->pbo, gl, tex->use_pbo && !buf,
+                          tex_gl->target, tex_gl->format, tex_gl->type,
+                          tex->params.w, tex->params.h, src, stride,
+                          0, 0, tex->params.w, tex->params.h);
+        break;
+    case 3:
+        gl->PixelStorei(GL_UNPACK_ALIGNMENT, 1);
+        gl->TexImage3D(GL_TEXTURE_3D, 0, tex_gl->internal_format, tex->params.w,
+                       tex->params.h, tex->params.d, 0, tex_gl->format,
+                       tex_gl->type, src);
+        gl->PixelStorei(GL_UNPACK_ALIGNMENT, 4);
+        break;
+    }
+
+    gl->BindTexture(tex_gl->target, 0);
+
+    if (buf) {
+        gl->BindBuffer(GL_PIXEL_UNPACK_BUFFER, 0);
+        // Make sure the PBO is not reused until GL is done with it. If a
+        // previous operation is pending, "update" it by creating a new
+        // fence that will cover the previous operation as well.
+        gl->DeleteSync(buf_gl->fence);
+        buf_gl->fence = gl->FenceSync(GL_SYNC_GPU_COMMANDS_COMPLETE, 0);
+    }
+}
+
+static void gl_destroy_mapped_buffer(struct ra *ra, struct ra_mapped_buffer *buf)
+{
+    struct ra_gl *p = ra->priv;
+    GL *gl = p->gl;
+    struct ra_mapped_buffer_gl *buf_gl = buf->priv;
+
+    gl->DeleteSync(buf_gl->fence);
+    gl->BindBuffer(GL_PIXEL_UNPACK_BUFFER, buf_gl->pbo);
+    if (buf->data)
+        gl->UnmapBuffer(GL_PIXEL_UNPACK_BUFFER);
+    gl->BindBuffer(GL_PIXEL_UNPACK_BUFFER, 0);
+    gl->DeleteBuffers(1, &buf_gl->pbo);
+
+    talloc_free(buf_gl);
+    talloc_free(buf);
+}
+
+static struct ra_mapped_buffer *gl_create_mapped_buffer(struct ra *ra,
+                                                        size_t size)
+{
+    struct ra_gl *p = ra->priv;
+    GL *gl = p->gl;
+
+    if (gl->version < 440)
+        return NULL;
+
+    struct ra_mapped_buffer *buf = talloc_zero(NULL, struct ra_mapped_buffer);
+    buf->size = size;
+    buf->preferred_align = 1;
+
+    struct ra_mapped_buffer_gl *buf_gl = buf->priv =
+        talloc_zero(NULL, struct ra_mapped_buffer_gl);
+
+    unsigned flags = GL_MAP_READ_BIT | GL_MAP_WRITE_BIT | GL_MAP_PERSISTENT_BIT |
+                     GL_MAP_COHERENT_BIT;
+
+    gl->GenBuffers(1, &buf_gl->pbo);
+    gl->BindBuffer(GL_PIXEL_UNPACK_BUFFER, buf_gl->pbo);
+    gl->BufferStorage(GL_PIXEL_UNPACK_BUFFER, size, NULL, flags);
+    buf->data = gl->MapBufferRange(GL_PIXEL_UNPACK_BUFFER, 0, buf->size, flags);
+    gl->BindBuffer(GL_PIXEL_UNPACK_BUFFER, 0);
+    if (!buf->data) {
+        gl_check_error(gl, ra->log, "mapping buffer");
+        gl_destroy_mapped_buffer(ra, buf);
+        return NULL;
+    }
+
+    return buf;
+}
+
+static bool gl_poll_mapped_buffer(struct ra *ra, struct ra_mapped_buffer *buf)
+{
+    struct ra_gl *p = ra->priv;
+    GL *gl = p->gl;
+    struct ra_mapped_buffer_gl *buf_gl = buf->priv;
+
+    if (buf_gl->fence) {
+        GLenum res = gl->ClientWaitSync(buf_gl->fence, 0, 0); // non-blocking
+        if (res == GL_ALREADY_SIGNALED) {
+            gl->DeleteSync(buf_gl->fence);
+            buf_gl->fence = NULL;
+        }
+    }
+
+    return !buf_gl->fence;
+}
+
+static struct ra_fns ra_fns_gl = {
+    .destroy                = gl_destroy,
+    .tex_create             = gl_tex_create,
+    .tex_destroy            = gl_tex_destroy,
+    .tex_upload             = gl_tex_upload,
+    .create_mapped_buffer   = gl_create_mapped_buffer,
+    .destroy_mapped_buffer  = gl_destroy_mapped_buffer,
+    .poll_mapped_buffer     = gl_poll_mapped_buffer,
+};
+