[Mesa-dev] [PATCH v2 7/8] egl: Add EGL_WAYLAND_PLANE_WL attribute

[Gwenole Beauchesne]

Hi,

2012/7/9 Kristian Høgsberg <krh at bitplanet.net>:

> +   switch (buffer->format) {
> +   case WL_DRM_FORMAT_ARGB8888:
> +   case WL_DRM_FORMAT_XRGB8888:
> +      if (plane > 0) {
> +         _eglError(EGL_BAD_PARAMETER, "dri2_create_image_wayland_wl_buffer");
> +         return NULL;
> +      }
> +      width = buffer->buffer.width;
> +      height = buffer->buffer.height;
> +      format = buffer->driver_format;
> +      offset = buffer->offset[0];
> +      stride = buffer->stride[0];
> +      cpp = 4;

For all of those, I'd suggest a map table or the use of some format
descriptor. e.g.

struct dri_image_descriptor {
    unsigned int        num_planes; /* Max number of planes */
    struct {
        unsigned int    format;     /* __DRI_IMAGE_FORMAT_xxx */
        unsigned char   cpp;        /* Number of components per pixel */
        unsigned char   w_shift;    /* Plane width = Image width >> w_shift */
        unsigned char   h_shift;    /* Plane height = Image height >> h_shift */
    }                   planes[3];
};

static const struct dri_image_descriptor dri_image_argb8888_desc = {
    1, { { __DRI_IMAGE_FORMAT_ARGB8888, 4, 0, 0 }, } };
static const struct dri_image_descriptor dri_image_xrgb8888_desc = {
    1, { { __DRI_IMAGE_FORMAT_XRGB8888, 4, 0, 0 }, } };
static const struct dri_image_descriptor dri_image_nv12_desc = {
    2, { { __DRI_IMAGE_FORMAT_R8,      1, 0, 0 },
         { __DRI_IMAGE_FORMAT_GR88,    2, 1, 1 }, } };
[...]

That way, we could also re-use the same descriptors for other
non-Wayland buffers.

switch (buffer->format) {
case WL_DRM_FORMAT_ARGB8888:
    m = &image_argb8888_desc;
    break;
}

and thus reducing to

if (plane >= m->num_planes) {
    _eglError(EGL_BAD_PARAMETER, "dri2_create_image_wayland_wl_buffer");
    return NULL;
}
width = buffer->buffer.width >> m->planes[plane].w_shift;
height = buffer->buffer.height >> m->planes[plane].h_shift;
cpp = m->planes[plane].cpp;

BTW, could you please also add YUV 4:2:2 and 4:4:4 back? That's useful
to JPEG decoded surfaces. :)

Thanks,
Gwenole.