win: support animatable cropping

Signed-off-by: Yuxuan Shui <yshuiv7@gmail.com>

src/region.h

@@ -200,3 +200,11 @@ region_symmetric_difference_local(region_t *result, region_t *scratch,
 	pixman_region32_subtract(scratch, scratch, region1);
 	pixman_region32_union(result, result, scratch);
 }
+
+static inline region_t region_from_box(struct ibox a) {
+	region_t ret;
+	unsigned width = (unsigned)(min2(INT_MAX - a.origin.x, a.size.width)),
+	         height = (unsigned)(min2(INT_MAX - a.origin.y, a.size.height));
+	pixman_region32_init_rect(&ret, a.origin.x, a.origin.y, width, height);
+	return ret;
+}

src/renderer/command_builder.c

@@ -18,6 +18,7 @@ commands_for_window_body(struct layer *layer, struct backend_command *cmd,
                          const region_t *frame_region, bool inactive_dim_fixed,
                          double inactive_dim, double max_brightness) {
 	auto w = layer->win;
+	scoped_region_t crop = region_from_box(layer->crop);
 	auto mode = win_calc_mode_raw(layer->win);
 	int border_width = w->g.border_width;
 	double dim = 0;
@@ -51,6 +52,8 @@ commands_for_window_body(struct layer *layer, struct backend_command *cmd,
 	}
 	region_scale(&cmd->target_mask, layer->window.origin, layer->scale);
 	region_scale(&cmd->opaque_region, layer->window.origin, layer->scale);
+	pixman_region32_intersect(&cmd->target_mask, &cmd->target_mask, &crop);
+	pixman_region32_intersect(&cmd->opaque_region, &cmd->opaque_region, &crop);
 	cmd->op = BACKEND_COMMAND_BLIT;
 	cmd->source = BACKEND_COMMAND_SOURCE_WINDOW;
 	cmd->origin = layer->window.origin;
@@ -74,6 +77,7 @@ commands_for_window_body(struct layer *layer, struct backend_command *cmd,
 
 	pixman_region32_copy(&cmd->target_mask, frame_region);
 	region_scale(&cmd->target_mask, cmd->origin, layer->scale);
+	pixman_region32_intersect(&cmd->target_mask, &cmd->target_mask, &crop);
 	pixman_region32_init(&cmd->opaque_region);
 	cmd->op = BACKEND_COMMAND_BLIT;
 	cmd->origin = layer->window.origin;
@@ -140,6 +144,9 @@ command_for_shadow(struct layer *layer, struct backend_command *cmd,
 		    ivec2_sub(layer->window.origin, layer->shadow.origin);
 	}
 
+	scoped_region_t crop = region_from_box(layer->crop);
+	pixman_region32_intersect(&cmd->target_mask, &cmd->target_mask, &crop);
+
 	cmd->blit = (struct backend_blit_args){
 	    .opacity = layer->shadow_opacity,
 	    .max_brightness = 1,
@@ -170,6 +177,10 @@ command_for_blur(struct layer *layer, struct backend_command *cmd,
 		return 0;
 	}
 	region_scale(&cmd->target_mask, layer->window.origin, layer->scale);
+
+	scoped_region_t crop = region_from_box(layer->crop);
+	pixman_region32_intersect(&cmd->target_mask, &cmd->target_mask, &crop);
+
 	cmd->op = BACKEND_COMMAND_BLUR;
 	cmd->origin = (ivec2){};
 	if (w->corner_radius > 0) {

src/renderer/layout.c

@@ -51,6 +51,14 @@ static bool layer_from_window(struct layer *out_layer, struct managed_win *w, iv
 	                   .y = w->g.y + win_animatable_get(w, WIN_SCRIPT_OFFSET_Y)});
 	out_layer->window.size = vec2_as((vec2){.width = w->widthb * out_layer->scale.x,
 	                                        .height = w->heightb * out_layer->scale.y});
+	out_layer->crop.origin = vec2_as((vec2){
+	    .x = win_animatable_get(w, WIN_SCRIPT_CROP_X),
+	    .y = win_animatable_get(w, WIN_SCRIPT_CROP_Y),
+	});
+	out_layer->crop.size = vec2_as((vec2){
+	    .x = win_animatable_get(w, WIN_SCRIPT_CROP_WIDTH),
+	    .y = win_animatable_get(w, WIN_SCRIPT_CROP_HEIGHT),
+	});
 	if (w->shadow) {
 		out_layer->shadow_scale = (vec2){
 		    .x = win_animatable_get(w, WIN_SCRIPT_SHADOW_SCALE_X),
@@ -71,7 +79,7 @@ static bool layer_from_window(struct layer *out_layer, struct managed_win *w, iv
 	}
 
 	struct ibox screen = {.origin = {0, 0}, .size = size};
-	if (!ibox_overlap(out_layer->window, screen)) {
+	if (!ibox_overlap(out_layer->window, screen) || !ibox_overlap(out_layer->crop, screen)) {
 		goto out;
 	}
 

src/renderer/layout.h

@@ -45,6 +45,8 @@ struct layer {
 	float blur_opacity;
 	/// Opacity of this window's shadow
 	float shadow_opacity;
+	/// Crop the content of this layer to this box, in screen coordinates.
+	struct ibox crop;
 
 	/// How many commands are needed to render this layer
 	unsigned number_of_commands;
@@ -65,11 +67,6 @@ struct layer {
 	// things like blur-background-frame
 	// region_t opaque_region;
 	// region_t blur_region;
-
-	// TODO(yshui) support cropping
-	/// x and y offset for cropping. Anything to the top or
-	/// left of the crop point will be cropped out.
-	// uint32_t crop_x, crop_y;
 };
 
 /// Layout of windows at a specific frame

src/win.c

@@ -2209,6 +2209,8 @@ double win_animatable_get(const struct managed_win *w, enum win_script_output ou
 	case WIN_SCRIPT_BLUR_OPACITY: return w->state == WSTATE_MAPPED ? 1.0 : 0.0;
 	case WIN_SCRIPT_OPACITY:
 	case WIN_SCRIPT_SHADOW_OPACITY: return w->opacity;
+	case WIN_SCRIPT_CROP_X:
+	case WIN_SCRIPT_CROP_Y:
 	case WIN_SCRIPT_OFFSET_X:
 	case WIN_SCRIPT_OFFSET_Y:
 	case WIN_SCRIPT_SHADOW_OFFSET_X:
@@ -2217,6 +2219,8 @@ double win_animatable_get(const struct managed_win *w, enum win_script_output ou
 	case WIN_SCRIPT_SCALE_Y:
 	case WIN_SCRIPT_SHADOW_SCALE_X:
 	case WIN_SCRIPT_SHADOW_SCALE_Y: return 1;
+	case WIN_SCRIPT_CROP_WIDTH:
+	case WIN_SCRIPT_CROP_HEIGHT: return INFINITY;
 	}
 	unreachable();
 }

src/win.h

@@ -340,6 +340,10 @@ static const struct script_output_info win_script_outputs[] = {
     [WIN_SCRIPT_SCALE_Y] = {"scale-y"},
     [WIN_SCRIPT_SHADOW_SCALE_X] = {"shadow-scale-x"},
     [WIN_SCRIPT_SHADOW_SCALE_Y] = {"shadow-scale-y"},
+    [WIN_SCRIPT_CROP_X] = {"crop-x"},
+    [WIN_SCRIPT_CROP_Y] = {"crop-y"},
+    [WIN_SCRIPT_CROP_WIDTH] = {"crop-width"},
+    [WIN_SCRIPT_CROP_HEIGHT] = {"crop-height"},
     [NUM_OF_WIN_SCRIPT_OUTPUTS] = {NULL},
 };
 

src/win_defs.h

@@ -90,5 +90,13 @@ enum win_script_output {
 	WIN_SCRIPT_SHADOW_SCALE_X,
 	/// Vertical scale of the shadow
 	WIN_SCRIPT_SHADOW_SCALE_Y,
+	/// X coordinate of the origin of the crop box
+	WIN_SCRIPT_CROP_X,
+	/// Y coordinate of the origin of the crop box
+	WIN_SCRIPT_CROP_Y,
+	/// Width of the crop box
+	WIN_SCRIPT_CROP_WIDTH,
+	/// Height of the crop box
+	WIN_SCRIPT_CROP_HEIGHT,
 };
-#define NUM_OF_WIN_SCRIPT_OUTPUTS (WIN_SCRIPT_SHADOW_SCALE_Y + 1)
+#define NUM_OF_WIN_SCRIPT_OUTPUTS (WIN_SCRIPT_CROP_HEIGHT + 1)