render: Apply clip to rendered texture correctly

The new wlr_render_pass API provides src_box, dst_box and clip
parameters for texture rendition. Rather than clipping the dst_box,
which control the projection matrix and leads to compression, intersect
the damage and clip box and pass these as a clip parameter.

Fixes: https://github.com/swaywm/sway/issues/7579
Regressed by: https://github.com/swaywm/sway/pull/7552

1 files changed, 20 insertions, 16 deletions

diff --git a/sway/desktop/render.c b/sway/desktop/render.c
index 92ccfd09..552502aa 100644
--- a/sway/desktop/render.c
+++ b/sway/desktop/render.c
@@ -99,7 +99,7 @@ static void set_scale_filter(struct wlr_output *wlr_output,
 
 static void render_texture(struct render_context *ctx, struct wlr_texture *texture,
                 const struct wlr_fbox *_src_box, const struct wlr_box *dst_box,
-                enum wl_output_transform transform, float alpha) {
+                const struct wlr_box *clip_box, enum wl_output_transform transform, float alpha) {
         struct sway_output *output = ctx->output;
 
         struct wlr_box proj_box = *dst_box;
@@ -113,6 +113,12 @@ static void render_texture(struct render_context *ctx, struct wlr_texture *textu
         pixman_region32_init_rect(&damage, proj_box.x, proj_box.y,
                 proj_box.width, proj_box.height);
         pixman_region32_intersect(&damage, &damage, ctx->output_damage);
+
+        if (clip_box) {
+                pixman_region32_intersect_rect(&damage, &damage,
+                                clip_box->x, clip_box->y, clip_box->width, clip_box->height);
+        }
+
         bool damaged = pixman_region32_not_empty(&damage);
         if (!damaged) {
                 goto damage_finish;
@@ -151,19 +157,17 @@ static void render_surface_iterator(struct sway_output *output,
         struct wlr_fbox src_box;
         wlr_surface_get_buffer_source_box(surface, &src_box);
 
-        struct wlr_box proj_box = *_box;
-        scale_box(&proj_box, wlr_output->scale);
-
         struct wlr_box dst_box = *_box;
-        struct wlr_box *clip_box = data->clip_box;
-        if (clip_box != NULL) {
-                dst_box.width = fmin(dst_box.width, clip_box->width);
-                dst_box.height = fmin(dst_box.height, clip_box->height);
+        struct wlr_box clip_box = *_box;
+        if (data->clip_box != NULL) {
+                clip_box.width = fmin(dst_box.width, data->clip_box->width);
+                clip_box.height = fmin(dst_box.height, data->clip_box->height);
         }
         scale_box(&dst_box, wlr_output->scale);
+        scale_box(&clip_box, wlr_output->scale);
 
         render_texture(data->ctx, texture,
-                &src_box, &dst_box, surface->current.transform, alpha);
+                &src_box, &dst_box, &clip_box, surface->current.transform, alpha);
 
         wlr_presentation_surface_sampled_on_output(server.presentation, surface,
                 wlr_output);
@@ -320,20 +324,20 @@ static void render_saved_view(struct render_context *ctx, struct sway_view *view
                 }
 
                 struct wlr_box dst_box = proj_box;
-                scale_box(&proj_box, wlr_output->scale);
-
+                struct wlr_box clip_box = proj_box;
                 if (!floating) {
-                        dst_box.width = fmin(dst_box.width,
+                        clip_box.width = fmin(dst_box.width,
                                         view->container->current.content_width -
                                         (saved_buf->x - view->container->current.content_x) + view->saved_geometry.x);
-                        dst_box.height = fmin(dst_box.height,
+                        clip_box.height = fmin(dst_box.height,
                                         view->container->current.content_height -
                                         (saved_buf->y - view->container->current.content_y) + view->saved_geometry.y);
                 }
                 scale_box(&dst_box, wlr_output->scale);
+                scale_box(&clip_box, wlr_output->scale);
 
                 render_texture(ctx, saved_buf->buffer->texture,
-                        &saved_buf->source_box, &dst_box, saved_buf->transform, alpha);
+                        &saved_buf->source_box, &dst_box, &clip_box, saved_buf->transform, alpha);
         }
 
         // FIXME: we should set the surface that this saved buffer originates from
@@ -509,7 +513,7 @@ static void render_titlebar(struct render_context *ctx, struct sway_container *c
                         texture_box.width = ob_inner_width;
                 }
                 render_texture(ctx, marks_texture,
-                        NULL, &texture_box, WL_OUTPUT_TRANSFORM_NORMAL, con->alpha);
+                        NULL, &texture_box, NULL, WL_OUTPUT_TRANSFORM_NORMAL, con->alpha);
 
                 // Padding above
                 memcpy(&color, colors->background, sizeof(float) * 4);
@@ -580,7 +584,7 @@ static void render_titlebar(struct render_context *ctx, struct sway_container *c
                 }
 
                 render_texture(ctx, title_texture,
-                        NULL, &texture_box, WL_OUTPUT_TRANSFORM_NORMAL, con->alpha);
+                        NULL, &texture_box, NULL, WL_OUTPUT_TRANSFORM_NORMAL, con->alpha);
 
                 // Padding above
                 memcpy(&color, colors->background, sizeof(float) * 4);