[gtk/matthiasc/color-profiles] ngl: Determine intermediate format

[Matthias Clasen <matthiasc src gnome org>]

commit dbe2a9fa03cefbe76fbc50c5da63adab6a582417
Author: Matthias Clasen <mclasen redhat com>
Date:   Fri Oct 1 08:48:43 2021 -0400

    ngl: Determine intermediate format
    
    Look at the framebuffer we are given to determine
    what format to use for intermediate textures.
    
    Our preference here is to use fp16, if we can
    and it makes sense for the framebuffer we're given.

 gsk/ngl/gsknglrenderjob.c | 36 +++++++++++++++++++++++++++++-------
 1 file changed, 29 insertions(+), 7 deletions(-)
---
diff --git a/gsk/ngl/gsknglrenderjob.c b/gsk/ngl/gsknglrenderjob.c
index ff13fce842..1e66ff5a1b 100644
--- a/gsk/ngl/gsknglrenderjob.c
+++ b/gsk/ngl/gsknglrenderjob.c
@@ -164,6 +164,9 @@ struct _GskNglRenderJob
 
   /* If we should be rendering red zones over fallback nodes */
   guint debug_fallback : 1;
+
+  /* Format to use for intermediate textures */
+  int format;
 };
 
 typedef struct _GskNglRenderOffscreen
@@ -1276,7 +1279,7 @@ blur_offscreen (GskNglRenderJob       *job,
   if (!gsk_ngl_driver_create_render_target (job->driver,
                                              MAX (texture_to_blur_width, 1),
                                              MAX (texture_to_blur_height, 1),
-                                             GL_RGBA8,
+                                             job->format,
                                              GL_NEAREST, GL_NEAREST,
                                              &pass1))
     return 0;
@@ -1287,7 +1290,7 @@ blur_offscreen (GskNglRenderJob       *job,
   if (!gsk_ngl_driver_create_render_target (job->driver,
                                              texture_to_blur_width,
                                              texture_to_blur_height,
-                                             GL_RGBA8,
+                                             job->format,
                                              GL_NEAREST, GL_NEAREST,
                                              &pass2))
     return gsk_ngl_driver_release_render_target (job->driver, pass1, FALSE);
@@ -2199,7 +2202,7 @@ gsk_ngl_render_job_visit_blurred_inset_shadow_node (GskNglRenderJob     *job,
 
       if (!gsk_ngl_driver_create_render_target (job->driver,
                                                  texture_width, texture_height,
-                                                 GL_RGBA8,
+                                                 job->format,
                                                  GL_NEAREST, GL_NEAREST,
                                                  &render_target))
         g_assert_not_reached ();
@@ -2470,7 +2473,7 @@ gsk_ngl_render_job_visit_blurred_outset_shadow_node (GskNglRenderJob     *job,
 
       gsk_ngl_driver_create_render_target (job->driver,
                                            texture_width, texture_height,
-                                           GL_RGBA8,
+                                           job->format,
                                            GL_NEAREST, GL_NEAREST,
                                            &render_target);
 
@@ -3879,7 +3882,7 @@ gsk_ngl_render_job_visit_node_with_offscreen (GskNglRenderJob       *job,
 
   if (!gsk_ngl_driver_create_render_target (job->driver,
                                              scaled_width, scaled_height,
-                                             GL_RGBA8,
+                                             job->format,
                                              filter, filter,
                                              &render_target))
     g_assert_not_reached ();
@@ -3978,7 +3981,7 @@ gsk_ngl_render_job_render_flipped (GskNglRenderJob *job,
   if (!gsk_ngl_command_queue_create_render_target (job->command_queue,
                                                   MAX (1, job->viewport.size.width),
                                                   MAX (1, job->viewport.size.height),
-                                                  GL_RGBA8,
+                                                  job->format,
                                                   GL_NEAREST, GL_NEAREST,
                                                   &framebuffer_id, &texture_id))
     return;
@@ -4050,7 +4053,7 @@ gsk_ngl_render_job_render (GskNglRenderJob *job,
   gsk_ngl_driver_create_render_target (job->driver,
                                        job->viewport.size.width,
                                        job->viewport.size.height,
-                                       GL_RGBA8,
+                                       job->format,
                                        GL_NEAREST,
                                        GL_NEAREST,
                                        &render_target);
@@ -4098,6 +4101,24 @@ gsk_ngl_render_job_set_debug_fallback (GskNglRenderJob *job,
   job->debug_fallback = !!debug_fallback;
 }
 
+static int
+determine_format (GskNglDriver *driver,
+                  guint         framebuffer)
+{
+  int type, size;
+
+  glBindFramebuffer (GL_FRAMEBUFFER, framebuffer);
+  glGetFramebufferAttachmentParameteriv (GL_FRAMEBUFFER,  GL_COLOR_ATTACHMENT0, 
GL_FRAMEBUFFER_ATTACHMENT_COMPONENT_TYPE, &type);
+  glGetFramebufferAttachmentParameteriv (GL_FRAMEBUFFER,  GL_COLOR_ATTACHMENT0, 
GL_FRAMEBUFFER_ATTACHMENT_RED_SIZE, &size);
+
+  if (type == GL_FLOAT && size == 32)
+    return GL_RGBA32F;
+  else if (size > 8)
+    return GL_RGBA16F;
+  else
+    return GL_RGBA8;
+}
+
 GskNglRenderJob *
 gsk_ngl_render_job_new (GskNglDriver          *driver,
                         const graphene_rect_t *viewport,
@@ -4124,6 +4145,7 @@ gsk_ngl_render_job_new (GskNglDriver          *driver,
   job->scale_x = scale_factor;
   job->scale_y = scale_factor;
   job->viewport = *viewport;
+  job->format = determine_format (driver, framebuffer);
 
   gsk_ngl_render_job_set_alpha (job, 1.0f);
   gsk_ngl_render_job_set_projection_from_rect (job, viewport, NULL);