ngl: Fix offscreen rendering with transforms

There was confusion here about the handling of the
modelview transform. The modelview transform we are
getting is already set up for rendering the node
we are given, so keep it - except for possible adding
an extra scale on top when the texture would otherwise
be too big.

1 files changed, 10 insertions, 10 deletions

diff --git a/gsk/ngl/gsknglrenderjob.c b/gsk/ngl/gsknglrenderjob.c
index 08e99a7d19..1e62b4ecc7 100644
--- a/gsk/ngl/gsknglrenderjob.c
+++ b/gsk/ngl/gsknglrenderjob.c
@@ -3566,8 +3566,8 @@ gsk_ngl_render_job_visit_node_with_offscreen (GskNglRenderJob       *job,
 
   float scaled_width;
   float scaled_height;
-  float scale_x = job->scale_x;
-  float scale_y = job->scale_y;
+  float downscale_x = 1;
+  float downscale_y = 1;
 
   g_assert (job->command_queue->max_texture_size > 0);
 
@@ -3578,17 +3578,17 @@ gsk_ngl_render_job_visit_node_with_offscreen (GskNglRenderJob       *job,
   {
     int max_texture_size = job->command_queue->max_texture_size;
 
-    scaled_width = ceilf (offscreen->bounds->size.width * scale_x);
+    scaled_width = ceilf (offscreen->bounds->size.width * job->scale_x);
     if (scaled_width > max_texture_size)
       {
-        scale_x *= (float)max_texture_size / scaled_width;
+        downscale_x = (float)max_texture_size / scaled_width;
         scaled_width = max_texture_size;
       }
 
-    scaled_height = ceilf (offscreen->bounds->size.height * scale_y);
+    scaled_height = ceilf (offscreen->bounds->size.height * job->scale_y);
     if (scaled_height > max_texture_size)
       {
-        scale_y *= (float)max_texture_size / scaled_height;
+        downscale_y = (float)max_texture_size / scaled_height;
         scaled_height = max_texture_size;
       }
   }
@@ -3632,10 +3632,9 @@ gsk_ngl_render_job_visit_node_with_offscreen (GskNglRenderJob       *job,
 
   gsk_ngl_render_job_set_viewport (job, &viewport, &prev_viewport);
   gsk_ngl_render_job_set_projection_from_rect (job, &job->viewport, &prev_projection);
-  gsk_ngl_render_job_set_modelview (job, gsk_transform_scale (NULL, scale_x, scale_y));
+  if (downscale_x != 1 || downscale_y != 1)
+    gsk_ngl_render_job_push_modelview (job, gsk_transform_scale (NULL, downscale_x, downscale_y));
   prev_alpha = gsk_ngl_render_job_set_alpha (job, 1.0f);
-  job->offset_x = offset_x;
-  job->offset_y = offset_y;
 
   prev_fbo = gsk_ngl_command_queue_bind_framebuffer (job->command_queue, render_target->framebuffer_id);
   gsk_ngl_command_queue_clear (job->command_queue, 0, &job->viewport);
@@ -3648,7 +3647,8 @@ gsk_ngl_render_job_visit_node_with_offscreen (GskNglRenderJob       *job,
   if (offscreen->reset_clip)
     gsk_ngl_render_job_pop_clip (job);
 
-  gsk_ngl_render_job_pop_modelview (job);
+  if (downscale_x != 1 || downscale_y != 1)
+    gsk_ngl_render_job_pop_modelview (job);
   gsk_ngl_render_job_set_viewport (job, &prev_viewport, NULL);
   gsk_ngl_render_job_set_projection (job, &prev_projection);
   gsk_ngl_render_job_set_alpha (job, prev_alpha);