1 files changed, 17 insertions, 12 deletions

diff --git a/ui.cpp b/ui.cpp
index 387b5ac..e20a18c 100644
--- a/ui.cpp
+++ b/ui.cpp
@@ -310,8 +310,7 @@ void UI::Renderer::clear(const Rect& r) {
 	}
 }
 
-const App* g_app;
-void UI::Renderer::flush(int x, int y) {
+void UI::Renderer::flush_cell(int x, int y) {
 	Cmd* cmd = (Cmd*)cmd_buf;
 	Cmd* last = (Cmd*)(cmd_buf + cmd_buf_ptr);
 	Rect cell = Rect(
@@ -344,36 +343,43 @@ void UI::Renderer::flush(int x, int y) {
 	}
 }
 
-void UI::Renderer::flush() {
+bool UI::Renderer::flush(void* target) {
 	uint64_t* next = grid == grid_a? grid_b: grid_a;
 	uint64_t* h = grid;
 	uint64_t* p = next;
+	bool dirty = false;
+	pixels = (Colour*)target;
 	int i, j;
 	for (j = 0; j < grid_size; j++) {
 		for (i = 0; i < grid_size; i++) {
 			if (*p != *h) {
-				flush(i, j);
+				dirty = true;
+				flush_cell(i, j);
 			}
 			h++;
 			p++;
 		}
 	}
 	grid = next;
+	return dirty;
 }
 
 void UI::Renderer::resize(int w, int h) {
-	heap_free(arena, pixels);
-	pixels = (Colour*)heap_alloc(arena, w * h * sizeof *pixels);
-	assert(pixels != 0);
+	int i, e = grid_size * grid_size;
+	uint64_t* next = grid == grid_a? grid_b: grid_a;
 	bound = Rect(0, 0, w, h);
+	for (i = 0; i < e; i++)
+		next[i] = 0;
 }
 
 void UI::Renderer::init(Heap* heap, int w, int h) {
 	arena = heap;
-	pixels = (Colour*)heap_alloc(heap, w * h * sizeof *pixels);
-	assert(pixels != 0);
+	int i, e = grid_size * grid_size;
+	bound = Rect(0, 0, w, h);
 	bound = Rect(0, 0, w, h);
 	grid = grid_a;
+	for (i = 0; i < e; i++)
+		grid[i] = 0;
 }
 
 UI* UI::create(
@@ -479,13 +485,12 @@ void UI::update(Arena* s) {
 		layout(area.w, area.h);
 }
 
-void UI::render(Arena* s) {
+bool UI::render(Arena* s, void* pixels) {
 	if (area.w != ren.bound.w || area.h != ren.bound.h)
 		ren.resize(area.w, area.h);
 	ren.reset(ren.bound);
 	root->render();
-	g_app = app;
-	ren.flush();
+	return ren.flush(pixels);
 }
 
 void UI::draw_container(const Rect& bound, Colour c) {