From 0c7d22207bcc832a1e02959ced39f1fe930ba4a5 Mon Sep 17 00:00:00 2001
From: Matthias Clasen <mclasen@redhat.com>
Date: Fri, 19 Jan 2024 18:25:26 -0500
Subject: [PATCH] Hack: Download atlases

Make ngl save its current atlas every frame.
---
 gsk/gpu/gskgldevice.c         | 43 ++++++++++++++++++++++++++++++++++-
 gsk/gpu/gskglimage.c          |  6 +++++
 gsk/gpu/gskglimageprivate.h   |  3 +++
 gsk/gpu/gskgpudevice.c        |  7 ++++++
 gsk/gpu/gskgpudeviceprivate.h |  4 +++-
 gsk/gpu/gskgpurenderer.c      |  1 +
 6 files changed, 62 insertions(+), 2 deletions(-)

diff --git a/gsk/gpu/gskgldevice.c b/gsk/gpu/gskgldevice.c
index f33c172d54..46d99619bc 100644
--- a/gsk/gpu/gskgldevice.c
+++ b/gsk/gpu/gskgldevice.c
@@ -132,6 +132,47 @@ gsk_gl_device_make_current (GskGpuDevice *device)
   gdk_gl_context_make_current (gdk_display_get_gl_context (gsk_gpu_device_get_display (device)));
 }
 
+static void
+save_texture_to_png (GdkDisplay *display,
+                     int         texture_id,
+                     int         width,
+                     int         height,
+                     const char *filename)
+{
+  GdkGLTextureBuilder *builder;
+  GdkTexture *texture;
+
+  builder = gdk_gl_texture_builder_new ();
+  gdk_gl_texture_builder_set_context (builder, gdk_display_get_gl_context (display));
+  gdk_gl_texture_builder_set_id (builder, texture_id);
+  gdk_gl_texture_builder_set_width (builder, width);
+  gdk_gl_texture_builder_set_height (builder, height);
+
+  texture = gdk_gl_texture_builder_build (builder, NULL, NULL);
+  gdk_texture_save_to_png (texture, filename);
+
+  g_object_unref (texture);
+  g_object_unref (builder);
+}
+
+static void
+gsk_gl_device_end_frame (GskGpuDevice *device)
+{
+  GskGpuImage *image;
+  static int count = 0;
+  char *filename;
+
+  image = gsk_gpu_device_get_atlas_image (device);
+
+  filename = g_strdup_printf ("atlas%d.png", count++);
+  save_texture_to_png (gsk_gpu_device_get_display (device),
+                       gsk_gl_image_peek_texture (GSK_GL_IMAGE (image)),
+                       gsk_gpu_image_get_width (image),
+                       gsk_gpu_image_get_height (image),
+                       filename);
+  g_free (filename);
+}
+
 static void
 gsk_gl_device_finalize (GObject *object)
 {
@@ -159,6 +200,7 @@ gsk_gl_device_class_init (GskGLDeviceClass *klass)
   gpu_device_class->create_upload_image = gsk_gl_device_create_upload_image;
   gpu_device_class->create_download_image = gsk_gl_device_create_download_image;
   gpu_device_class->make_current = gsk_gl_device_make_current;
+  gpu_device_class->end_frame = gsk_gl_device_end_frame;
 
   object_class->finalize = gsk_gl_device_finalize;
 }
@@ -698,4 +740,3 @@ gsk_gl_device_find_gl_format (GskGLDevice      *self,
   /* fallbacks will always fallback to a supported format */
   g_assert_not_reached ();
 }
-
diff --git a/gsk/gpu/gskglimage.c b/gsk/gpu/gskglimage.c
index 4613a0287a..2447a9c1a1 100644
--- a/gsk/gpu/gskglimage.c
+++ b/gsk/gpu/gskglimage.c
@@ -316,3 +316,9 @@ gsk_gl_image_steal_texture (GskGLImage *self)
 
   return self->texture_id;
 }
+
+GLuint
+gsk_gl_image_peek_texture (GskGLImage *self)
+{
+  return self->texture_id;
+}
diff --git a/gsk/gpu/gskglimageprivate.h b/gsk/gpu/gskglimageprivate.h
index 9f7a959ece..fca620a41b 100644
--- a/gsk/gpu/gskglimageprivate.h
+++ b/gsk/gpu/gskglimageprivate.h
@@ -39,4 +39,7 @@ GLenum                  gsk_gl_image_get_gl_type                        (GskGLIm
 
 GLuint                  gsk_gl_image_steal_texture                      (GskGLImage             *self);
 
+GLuint                  gsk_gl_image_peek_texture                       (GskGLImage             *self);
+
+
 G_END_DECLS
diff --git a/gsk/gpu/gskgpudevice.c b/gsk/gpu/gskgpudevice.c
index 00dad93a05..8e52e00764 100644
--- a/gsk/gpu/gskgpudevice.c
+++ b/gsk/gpu/gskgpudevice.c
@@ -986,5 +986,12 @@ gsk_gpu_device_lookup_glyph_image (GskGpuDevice           *self,
   return cache->image;
 }
 
+void
+gsk_gpu_device_end_frame (GskGpuDevice *self)
+{
+  if (GSK_GPU_DEVICE_GET_CLASS (self))
+    GSK_GPU_DEVICE_GET_CLASS (self)->end_frame (self);
+}
+
 /* }}} */
 /* vim:set foldmethod=marker expandtab: */
diff --git a/gsk/gpu/gskgpudeviceprivate.h b/gsk/gpu/gskgpudeviceprivate.h
index 3424a26402..24cd189fe9 100644
--- a/gsk/gpu/gskgpudeviceprivate.h
+++ b/gsk/gpu/gskgpudeviceprivate.h
@@ -42,7 +42,7 @@ struct _GskGpuDeviceClass
                                                                          gsize                   width,
                                                                          gsize                   height);
   void                  (* make_current)                                (GskGpuDevice           *self);
-
+  void                  (* end_frame)                                   (GskGpuDevice           *self);
 };
 
 GType                   gsk_gpu_device_get_type                         (void) G_GNUC_CONST;
@@ -99,6 +99,8 @@ GskGpuImage *           gsk_gpu_device_lookup_glyph_image               (GskGpuD
                                                                          graphene_point_t       *out_origin);
 
 
+void                    gsk_gpu_device_end_frame                        (GskGpuDevice           *self);
+
 G_DEFINE_AUTOPTR_CLEANUP_FUNC(GskGpuDevice, g_object_unref)
 
 G_END_DECLS
diff --git a/gsk/gpu/gskgpurenderer.c b/gsk/gpu/gskgpurenderer.c
index b23142a140..848c81b729 100644
--- a/gsk/gpu/gskgpurenderer.c
+++ b/gsk/gpu/gskgpurenderer.c
@@ -423,6 +423,7 @@ gsk_gpu_renderer_render (GskRenderer          *renderer,
   gsk_gpu_device_queue_gc (priv->device);
 
   gdk_draw_context_end_frame (priv->context);
+  gsk_gpu_device_end_frame (priv->device);
 
   g_clear_pointer (&render_region, cairo_region_destroy);
 }