From e8baea58dd5c92b62c4eef1b5c1ca9648f44e7d7 Mon Sep 17 00:00:00 2001
From: quou <quou@disroot.org>
Date: Mon, 30 Dec 2024 12:44:28 +1100
Subject: ui renderer clipping

---
 ui.cpp | 91 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++----------
 1 file changed, 78 insertions(+), 13 deletions(-)

(limited to 'ui.cpp')

diff --git a/ui.cpp b/ui.cpp
index 2060a78..5814204 100644
--- a/ui.cpp
+++ b/ui.cpp
@@ -129,6 +129,9 @@ UI::Colour::Colour(unsigned rgb, uint8_t a):
 	b((rgb)       & 0xff),
 	a(a) {}
 
+UI::Rect::Rect(int x, int y, int w, int h):
+	x(x), y(y), w(w), h(h) {}
+
 void UI::Vertex_Buffer::init(Device* dev) {
 	buf.init(
 		dev,
@@ -138,6 +141,7 @@ void UI::Vertex_Buffer::init(Device* dev) {
 	);
 	init_indices(dev);
 	usage = 0;
+	start = 0;
 	next = 0;
 }
 
@@ -199,6 +203,7 @@ void UI::Vertex_Buffer::add_quad(
 ) {
 	Vertex* verts;
 	int index = usage * 4;
+	int* scissor = ui->pipeline->scissor;
 	float r, g, b, a;
 	if (usage >= vertex_buffer_count) {
 		if (!next) {
@@ -208,6 +213,35 @@ void UI::Vertex_Buffer::add_quad(
 		next->add_quad(ui, x, y, w, h, u0, v0, u1, v1, col);
 		return;
 	}
+	if (
+		clip.x < scissor[0] ||
+		clip.y < scissor[1] ||
+		clip.x + clip.w > scissor[0] + scissor[2] ||
+		clip.y + clip.h > scissor[1] + scissor[3] ||
+		((
+			clip.x != scissor[0] ||
+			clip.y != scissor[1] ||
+			clip.w != scissor[2] ||
+			clip.h != scissor[3]
+		) && (
+			x < clip.x ||
+			y < clip.y ||
+			x + w > clip.x + clip.w ||
+			y + h > clip.y + clip.h
+		))
+	) {
+		ui->mesh.draw(
+			ui,
+			ui->device->get_ctx(),
+			*ui->pipeline,
+			*ui->render_pass
+		);
+		scissor[0] = clip.x;
+		scissor[1] = clip.y;
+		scissor[2] = clip.w;
+		scissor[3] = clip.h;
+		ui->pipeline->hash();
+	}
 	r = col.r_f();
 	g = col.g_f();
 	b = col.b_f();
@@ -254,17 +288,44 @@ void UI::Vertex_Buffer::add_text(
 	const char* txt,
 	Colour col
 ) {
-	for (; *txt; txt++)
-		add_char(ui, x += 10, y, *txt, col);
+	for (; *txt; txt++, x += 10)
+		add_char(ui, x, y, *txt, col);
 }
 
 void UI::Vertex_Buffer::update_buffer(Context& ctx) {
 	buf.update(ctx);
+}
+
+void UI::Vertex_Buffer::reset(const Rect& c) {
+	start = 0;
+	usage = 0;
+	dirty = true;
+	clip = c;
+	if (next)
+		next->reset(c);
+}
+
+void UI::Vertex_Buffer::set_clip(const Rect& r) {
+	clip = r;
 	if (next)
-		next->update_buffer(ctx);
+		next->set_clip(r);
 }
 
-void UI::Vertex_Buffer::draw(UI* ui, Context& ctx, Pipeline& pip, Render_Pass& rp) {
+void UI::Vertex_Buffer::draw(
+	UI* ui,
+	Context& ctx,
+	Pipeline& pip,
+	Render_Pass& rp
+) {
+	if (usage == start) {
+		if (next)
+			next->draw(ui, ctx, pip, rp);
+		return;
+	}
+	if (dirty) {
+		update_buffer(ctx);
+		dirty = false;
+	}
 	Vertex_Buffer_Binding binding[] = {{
 		.id = buf.gpuonly,
 		.offset = 0,
@@ -277,12 +338,13 @@ void UI::Vertex_Buffer::draw(UI* ui, Context& ctx, Pipeline& pip, Render_Pass& r
 	Draw d{};
 	d.verts = binding;
 	d.inds = indb;
-	d.vertex_count = usage * 6;
+	d.vertex_count = (usage - start) * 6;
 	d.instance_count = 1;
+	d.first_vertex = start * 6;
 	ctx.submit(d, pip, rp);
 	if (next)
 		next->draw(ui, ctx, pip, rp);
-	usage = 0;
+	start = usage;
 }
 
 UI* UI::create(Device* dev, Arena* a, Shader_Id sh) {
@@ -345,7 +407,6 @@ void UI::update(Arena* s) {
 }
 
 void UI::render(Arena* s, Texture_Id target) {
-	int i, c = 2000;
 	Context& ctx = device->get_ctx();
 	Texture& t = device->get_texture(target);
 	UI_CBuffer* config = (UI_CBuffer*)cbuffer.map(device);
@@ -358,12 +419,10 @@ void UI::render(Arena* s, Texture_Id target) {
 	cbuffer.unmap(device);
 	cbuffer.update(ctx);
 
-	mesh.add_text(this, 10, 10, "Hello, world!", 0xff00ff);
-
 	Pipeline_Builder pb(s, device);
 	pb.begin_rp();
 	pb.rp_target(device->get_backbuffer(), Clear_Mode::restore);
-	Render_Pass& pass = pb.build_rp();
+	render_pass = &pb.build_rp();
 
 	pb.begin();
 	pb.shader(shader);
@@ -375,8 +434,14 @@ void UI::render(Arena* s, Texture_Id target) {
 	);
 	pb.cbuffer(shader_info.config_binding, cbuffer.gpuonly);
 	pb.texture(shader_info.atlas_binding, atlas, sampler);
-	Pipeline& pip = pb.build();
+	pipeline = &pb.build();
 
-	mesh.update_buffer(ctx);
-	mesh.draw(this, ctx, pip, pass);
+	mesh.reset(Rect(0, 0, t.w, t.h));
+	mesh.add_text(this, 10, 10, "Hello, world!", 0xffffff);
+	mesh.add_text(this, 10, 30, "Hello, world!", 0xffffff);
+	mesh.set_clip(Rect(0, 0, 35, 100));
+	mesh.add_text(this, 10, 50, "Hello, world!", 0xffffff);
+	mesh.set_clip(Rect(0, 0, t.w, t.h));
+	mesh.add_text(this, 10, 70, "Hello, world!", 0xffffff);
+	mesh.draw(this, ctx, *pipeline, *render_pass);
 }
-- 
cgit v1.2.3-54-g00ecf