make the pipeline builder a bit cleaner to use

2 files changed, 77 insertions, 42 deletions

diff --git a/pipeline.cpp b/pipeline.cpp
index 647ff49..b187807 100644
--- a/pipeline.cpp
+++ b/pipeline.cpp
@@ -11,12 +11,13 @@ extern "C" {
 Pipeline_Builder::Pipeline_Builder(Arena* arena, Device* dev):
 	arena(arena), dev(dev) {}
 
-void Pipeline_Builder::begin_rp() {
+Pipeline_Builder& Pipeline_Builder::begin_rp() {
 	pass = (Render_Pass*)arena_alloc(arena, sizeof *pass);
 	zero(pass, sizeof *pass);
+	return *this;
 }
 
-void Pipeline_Builder::rp_target(Texture_Id id, Colour clear) {
+Pipeline_Builder& Pipeline_Builder::rp_target(Texture_Id id, Colour clear) {
 	int i = pass->colour_count++;
 	Texture& texture = dev->get_texture(id);
 	Render_Pass::Target t{
@@ -27,9 +28,10 @@ void Pipeline_Builder::rp_target(Texture_Id id, Colour clear) {
 	};
 	assert(i < max_colour_attachments);
 	pass->colours[i] = t;
+	return *this;
 }
 
-void Pipeline_Builder::rp_target(Texture_Id id, Clear_Mode clear) {
+Pipeline_Builder& Pipeline_Builder::rp_target(Texture_Id id, Clear_Mode clear) {
 	int i = pass->colour_count++;
 	Texture& texture = dev->get_texture(id);
 	Render_Pass::Target t{
@@ -41,9 +43,10 @@ void Pipeline_Builder::rp_target(Texture_Id id, Clear_Mode clear) {
 	assert(i < max_colour_attachments);
 	assert(clear != Clear_Mode::clear);
 	pass->colours[i] = t;
+	return *this;
 }
 
-void Pipeline_Builder::rp_depth_target(Texture_Id id, float clear) {
+Pipeline_Builder& Pipeline_Builder::rp_depth_target(Texture_Id id, float clear) {
 	Texture& texture = dev->get_texture(id);
 	Render_Pass::Target t{
 		.id = id,
@@ -52,9 +55,10 @@ void Pipeline_Builder::rp_depth_target(Texture_Id id, float clear) {
 		.clear = { .depth = clear }
 	};
 	pass->depth = t;
+	return *this;
 }
 
-void Pipeline_Builder::rp_depth_target(Texture_Id id, Clear_Mode mode) {
+Pipeline_Builder& Pipeline_Builder::rp_depth_target(Texture_Id id, Clear_Mode mode) {
 	Texture& texture = dev->get_texture(id);
 	Render_Pass::Target t{
 		.id = id,
@@ -64,6 +68,7 @@ void Pipeline_Builder::rp_depth_target(Texture_Id id, Clear_Mode mode) {
 	};
 	assert(mode != Clear_Mode::clear);
 	pass->depth = t;
+	return *this;
 }
 
 void Pipeline_Builder::validate_rp() {
@@ -118,24 +123,40 @@ Render_Pass& Pipeline_Builder::build_rp() {
 	return *pass;
 }
 
-void Pipeline_Builder::begin() {
+Pipeline_Builder& Pipeline_Builder::begin(const Render_Pass* p) {
 	pip = (Pipeline*)arena_alloc(arena, sizeof *pip);
 	zero(pip, sizeof *pip);
 	if (dev) {
-		Texture_Id backbuffer_id = dev->get_backbuffer();
-		Texture& backbuffer = dev->get_texture(backbuffer_id);
+		int w = 0, h = 0;
+		if (p) {
+			if (p->depth.id) {
+				Texture& d = dev->get_texture(p->depth.id);
+				w = d.w;
+				h = d.h;
+			} else if (p->colour_count) {
+				Texture& c = dev->get_texture(p->colours[0].id);
+				w = c.w;
+				h = c.h;
+			}
+		} else {
+			Texture_Id backbuffer_id = dev->get_backbuffer();
+			Texture& backbuffer = dev->get_texture(backbuffer_id);
+			w = backbuffer.w;
+			h = backbuffer.h;
+		}
 		pip->scissor[0] = 0;
 		pip->scissor[1] = 0;
-		pip->scissor[2] = backbuffer.w;
-		pip->scissor[3] = backbuffer.h;
+		pip->scissor[2] = w;
+		pip->scissor[3] = h;
 		pip->viewport[0] = 0;
 		pip->viewport[1] = 0;
-		pip->viewport[2] = backbuffer.w;
-		pip->viewport[3] = backbuffer.h;
+		pip->viewport[2] = w;
+		pip->viewport[3] = h;
 	}
+	return *this;
 }
 
-void Pipeline_Builder::viewport(
+Pipeline_Builder& Pipeline_Builder::viewport(
 	int x,
 	int y,
 	int w,
@@ -145,9 +166,10 @@ void Pipeline_Builder::viewport(
 	pip->viewport[1] = y;
 	pip->viewport[2] = w;
 	pip->viewport[3] = h;
+	return *this;
 }
 
-void Pipeline_Builder::scissor(
+Pipeline_Builder& Pipeline_Builder::scissor(
 	int x,
 	int y,
 	int w,
@@ -157,19 +179,22 @@ void Pipeline_Builder::scissor(
 	pip->scissor[1] = y;
 	pip->scissor[2] = w;
 	pip->scissor[3] = h;
+	return *this;
 }
 
-void Pipeline_Builder::depth(bool test, bool write, Depth_Mode mode) {
+Pipeline_Builder& Pipeline_Builder::depth(bool test, bool write, Depth_Mode mode) {
 	pip->depth_test = test;
 	pip->depth_write = write;
 	pip->depth_mode = mode;
+	return *this;
 }
 
-void Pipeline_Builder::geo(Geo_Type type) {
+Pipeline_Builder& Pipeline_Builder::geo(Geo_Type type) {
 	pip->geo = type;
+	return *this;
 }
 
-void Pipeline_Builder::blend(
+Pipeline_Builder& Pipeline_Builder::blend(
 	Blend_Mode mode,
 	Blend_Factor src,
 	Blend_Factor dst
@@ -182,13 +207,15 @@ void Pipeline_Builder::blend(
 		src,
 		dst
 	);
+	return *this;
 }
 
-void Pipeline_Builder::cull(Cull_Mode mode) {
+Pipeline_Builder& Pipeline_Builder::cull(Cull_Mode mode) {
 	pip->cull_mode = mode;
+	return *this;
 }
 
-void Pipeline_Builder::blend(
+Pipeline_Builder& Pipeline_Builder::blend(
 	Blend_Mode mode_col,
 	Blend_Factor src_col,
 	Blend_Factor dst_col,
@@ -203,13 +230,15 @@ void Pipeline_Builder::blend(
 	pip->blend_mode_alpha = mode_alpha;
 	pip->blend_src_alpha = src_alpha;
 	pip->blend_dst_alpha = dst_alpha;
+	return *this;
 }
 
-void Pipeline_Builder::shader(Shader_Id s) {
+Pipeline_Builder& Pipeline_Builder::shader(Shader_Id s) {
 	pip->shader = s;
+	return *this;
 }
 
-void Pipeline_Builder::texture(
+Pipeline_Builder& Pipeline_Builder::texture(
 	int binding,
 	Texture_Id t,
 	Sampler_Id s
@@ -223,9 +252,10 @@ void Pipeline_Builder::texture(
 	d->type = Descriptor::Type::texture;
 	td->sampler = s;
 	td->texture = t;
+	return *this;
 }
 
-void Pipeline_Builder::cbuffer(
+Pipeline_Builder& Pipeline_Builder::cbuffer(
 	int binding,
 	Buffer_Id id,
 	int offset,
@@ -241,9 +271,10 @@ void Pipeline_Builder::cbuffer(
 	cd->buffer = id;
 	cd->offset = offset;
 	cd->size = size;
+	return *this;
 }
 
-void Pipeline_Builder::sbuffer(
+Pipeline_Builder& Pipeline_Builder::sbuffer(
 	int binding,
 	Buffer_Id id,
 	int offset,
@@ -259,10 +290,12 @@ void Pipeline_Builder::sbuffer(
 	cd->buffer = id;
 	cd->offset = offset;
 	cd->size = size;
+	return *this;
 }
 
-void Pipeline_Builder::vertex_format(Vertex_Format_Id vf) {
+Pipeline_Builder& Pipeline_Builder::vertex_format(Vertex_Format_Id vf) {
 	pip->vertex_format = vf;
+	return *this;
 }
 
 Pipeline& Pipeline_Builder::build() {
diff --git a/video.hpp b/video.hpp
index ccc1f11..b8293fa 100644
--- a/video.hpp
+++ b/video.hpp
@@ -298,21 +298,23 @@ struct Pipeline_Builder {
 
 	Pipeline_Builder(Arena* arena, Device* dev);
 
-	void begin_rp();
-	void rp_target(Texture_Id id, Colour clear_colour);
-	void rp_target(Texture_Id id, Clear_Mode mode);
-	void rp_depth_target(Texture_Id id, float clear_depth);
-	void rp_depth_target(Texture_Id id, Clear_Mode mode);
+	using PB = Pipeline_Builder&;
+
+	PB& begin_rp();
+	PB& rp_target(Texture_Id id, Colour clear_colour);
+	PB& rp_target(Texture_Id id, Clear_Mode mode);
+	PB& rp_depth_target(Texture_Id id, float clear_depth);
+	PB& rp_depth_target(Texture_Id id, Clear_Mode mode);
 	Render_Pass& build_rp();
 	void validate_rp();
 
-	void begin();
-	void viewport(int x, int y, int w, int h);
-	void scissor(int x, int y, int w, int h);
-	void depth(bool test, bool write, Depth_Mode mode);
-	void geo(Geo_Type type);
-	void blend(Blend_Mode mode, Blend_Factor src, Blend_Factor dst);
-	void blend(
+	PB& begin(const Render_Pass* p = 0);
+	PB& viewport(int x, int y, int w, int h);
+	PB& scissor(int x, int y, int w, int h);
+	PB& depth(bool test, bool write, Depth_Mode mode);
+	PB& geo(Geo_Type type);
+	PB& blend(Blend_Mode mode, Blend_Factor src, Blend_Factor dst);
+	PB& blend(
 		Blend_Mode mode_col,
 		Blend_Factor src_col,
 		Blend_Factor dst_col,
@@ -320,17 +322,17 @@ struct Pipeline_Builder {
 		Blend_Factor src_alpha,
 		Blend_Factor dst_alpha
 	);
-	void cull(Cull_Mode mode);
-	void shader(Shader_Id s);
-	void vertex_format(Vertex_Format_Id vf);
-	void texture(int binding, Texture_Id t, Sampler_Id s);
-	void cbuffer(
+	PB& cull(Cull_Mode mode);
+	PB& shader(Shader_Id s);
+	PB& vertex_format(Vertex_Format_Id vf);
+	PB& texture(int binding, Texture_Id t, Sampler_Id s);
+	PB& cbuffer(
 		int binding,
 		Buffer_Id id,
 		int offset = 0,
 		int size = 0
 	);
-	void sbuffer(
+	PB& sbuffer(
 		int binding,
 		Buffer_Id id,
 		int offset = 0,