environment mapping

4 files changed, 198 insertions, 9 deletions

diff --git a/c2.cpp b/c2.cpp
index 0c231eb..5268117 100644
--- a/c2.cpp
+++ b/c2.cpp
@@ -230,10 +230,34 @@ struct Sky {
 		Sampler_Id sampler,
 		const Camera& cam
 	) {
+		Texture_Id backbuffer_id = d->get_backbuffer();
+		Texture& backbuffer = d->get_texture(backbuffer_id);
 		Cbuffer* cb = (Cbuffer*)config.map(d);
 		cb->iview = cam.get_view().inverse();
 		cb->iprojection = cam.get_proj().inverse();
 		config.unmap(d);
+		render_imp(
+			d,
+			a,
+			pass,
+			sampler,
+			config.gpuonly,
+			0,
+			backbuffer.w,
+			backbuffer.h
+		);
+	}
+
+	void render_imp(
+		Device* d,
+		Arena* a,
+		Render_Pass& pass,
+		Sampler_Id sampler,
+		Buffer_Id cbuffer,
+		int offset,
+		int w,
+		int h
+	) {
 		Context& ctx = d->get_ctx();
 		Pipeline_Builder pb(a, d);
 		pb.begin();
@@ -244,7 +268,9 @@ struct Sky {
 			texture,
 			sampler
 		);
-		pb.cbuffer(cfg_binding, config.gpuonly);
+		pb.viewport(0, 0, w, h);
+		pb.scissor(0, 0, w, h);
+		pb.cbuffer(cfg_binding, cbuffer, offset, sizeof(Cbuffer));
 		pb.depth(true, false, Depth_Mode::equal);
 		Pipeline& pip = pb.build();
 
@@ -263,6 +289,143 @@ struct Sky {
 	}
 };
 
+struct Env_Probe {
+	Texture_Id cubemap;
+	Texture_Id cubemap_depth;
+	Texture_Id faces[6];
+	Sampler_Id sampler;
+	int cubemap_res;
+	Staged_Buffer config;
+
+	void init(Device* dev, Asset_Arena* assets, int res) {
+		int i;
+		Sampler_State s{};
+		cubemap_res = res;
+		s.min = Filter_Mode::linear;
+		s.mag = Filter_Mode::linear;
+		s.address_u = Address_Mode::repeat;
+		s.address_v = Address_Mode::repeat;
+		sampler = dev->create_sampler("env probe sampler", s);
+		cubemap_depth = dev->create_texture(
+			"env cubemap depth",
+			texture_format_d16,
+			Texture_Flags::sampleable | Texture_Flags::depth_stencil_target,
+			res,
+			res,
+			1,
+			1,
+			1,
+			0
+		);
+		cubemap = dev->create_texture(
+			"env cubemap",
+			texture_format_rgba16f,
+			Texture_Flags::cubemap |
+			Texture_Flags::colour_target |
+			Texture_Flags::sampleable,
+			res,
+			res,
+			1,
+			1,
+			1,
+			Buffer_Id(0)
+		);
+		for (i = 0; i < 6; i++) {
+			faces[i] = dev->alias_texture(
+				cubemap,
+				"env cubemap face",
+				texture_format_rgba16f,
+				Texture_Flags::colour_target |
+				Texture_Flags::sampleable,
+				res,
+				res,
+				1,
+				1,
+				1,
+				0,
+				i
+			);
+		}
+		config.init(
+			dev,
+			"env probe sky cbuffer",
+			sizeof(Sky::Cbuffer) * 6,
+			Buffer_Flags::constant_buffer
+		);
+	}
+
+	void destroy(Device* dev) {
+		int i;
+		for (i = 0; i < 6; i++) {
+			dev->destroy_texture(faces[i]);
+		}
+		dev->destroy_texture(cubemap_depth);
+		dev->destroy_sampler(sampler);
+		dev->destroy_texture(cubemap);
+		config.destroy(dev);
+	}
+
+	void update_cbuffer(Device* dev) {
+		int i;
+		Context& ctx = dev->get_ctx();
+		Sky::Cbuffer* bufs = (Sky::Cbuffer*)config.map(dev);
+		m4f iproj = m4f::pers(
+			90.0f,
+			1.0f,
+			0.1f,
+			1000.0f
+		).inverse();
+		v3f dirs[] = {
+			v3f( 1.0f,  0.0f,  0.0f),
+			v3f(-1.0f,  0.0f,  0.0f),
+			v3f( 0.0f,  1.0f,  0.0f),
+			v3f( 0.0f, -1.0f,  0.0f),
+			v3f( 0.0f,  0.0f, -1.0f),
+			v3f( 0.0f,  0.0f,  1.0f)
+		};
+		v3f ups[] = {
+			v3f(0.0f, 1.0f, 0.0f),
+			v3f(0.0f, 1.0f, 0.0f),
+			v3f(0.0f, 0.0f, 1.0f),
+			v3f(0.0f, 0.0f, -1.0f),
+			v3f(0.0f, 1.0f, 0.0f),
+			v3f(0.0f, 1.0f, 0.0f)
+		};
+		for (i = 0; i < 6; i++) {
+			Sky::Cbuffer& buf = bufs[i];
+			m4f view = m4f::lookat(v3f(0.0f), dirs[i], ups[i]);
+			buf.iview = view.inverse();
+			buf.iprojection = iproj;
+		}
+		config.unmap(dev);
+		config.update(ctx);
+	}
+
+	void render(Device* dev, Arena* a, Sky& sky) {
+		int i;
+		Pipeline_Builder pb(a, dev);
+		Context& ctx = dev->get_ctx();
+		update_cbuffer(dev);
+		for (i = 0; i < 6; i++) {
+			ctx.transition(faces[i], Resource_State::render_target);
+			pb.begin_rp();
+			pb.rp_target(faces[i], Clear_Mode::discard);
+			pb.rp_depth_target(cubemap_depth, 1.0f);
+			sky.render_imp(
+				dev,
+				a,
+				pb.build_rp(),
+				sampler,
+				config.gpuonly,
+				i * sizeof(Sky::Cbuffer),
+				cubemap_res,
+				cubemap_res
+			);
+			ctx.transition(faces[i], Resource_State::shader_read);
+		}
+	}
+};
+
 struct Config_Buffer {
 	float offset[2];
 };
@@ -286,6 +449,7 @@ extern "C" int entrypoint() {
 	Model_Scene scene;
 	Orbit_Cam camera;
 	Sky sky;
+	Env_Probe eprobe;
 	Buffer_Id vbo, cbuf;
 	Sampler_Id clamped_linear;
 	C2* app = App::create<C2>("c2");
@@ -350,6 +514,7 @@ extern "C" int entrypoint() {
 		(Model*)assets.load("monkey.mdl")
 	);
 	sky.init(dev, &assets);
+	eprobe.init(dev, &assets, 256);
 	camera.init();
 	while (app->running) {
 		Arena frame_arena;
@@ -428,6 +593,10 @@ extern "C" int entrypoint() {
 		pb.rp_depth_target(dev->get_depth_target(), Clear_Mode::restore);
 		Render_Pass& sky_pass = pb.build_rp();
 
+		ctx.debug_push("environment cube");
+		eprobe.render(dev, &frame_arena, sky);
+		ctx.debug_pop();
+
 		Texture& bb = dev->get_texture(dev->get_backbuffer());
 		monkey->transform = m4f::translate(
 			m4f::identity(),
@@ -450,10 +619,10 @@ extern "C" int entrypoint() {
 		scene.update(camera, dev);
 		ctx.debug_push("scene");
 		ctx.debug_push("depth prepass");
-		scene.render(dev, &frame_arena, depth_prepass, clamped_linear);
+		scene.render(dev, &frame_arena, depth_prepass, 0, clamped_linear);
 		ctx.debug_pop();
 		ctx.debug_push("forward");
-		scene.render(dev, &frame_arena, pass2, clamped_linear);
+		scene.render(dev, &frame_arena, pass2, eprobe.cubemap, clamped_linear);
 		ctx.debug_pop();
 		ctx.debug_pop();
 
@@ -479,6 +648,7 @@ extern "C" int entrypoint() {
 	}
 	scene.destroy(dev);
 	sky.destroy(dev);
+	eprobe.destroy(dev);
 	ui->destroy();
 	assets.destroy();
 	dev->destroy_texture(default_texture);
diff --git a/intermediate/surface.glsl b/intermediate/surface.glsl
index 5feb09f..8ec24f0 100644
--- a/intermediate/surface.glsl
+++ b/intermediate/surface.glsl
@@ -87,6 +87,10 @@ dimension: 2
 name: normal
 stage: fragment
 dimension: 2
+[texture]
+name: env_cube
+stage: fragment
+dimension: cube
 
 [target]
 name: colour
@@ -126,10 +130,9 @@ float specular_G1(float a, vec3 v, vec3 n) {
 	return ndv / (ndv * (1.0 - k) + k);
 }
 
-float specular_brdf(vec2 uv, vec3 l, vec3 v, vec3 n) {
+float specular_brdf(vec2 uv, vec3 ref, vec3 l, vec3 v, vec3 n) {
 	float ndl = max(dot(n, l), 0.0);
 	float ndv = max(dot(n, v), 0.0);
-	vec3 ref = reflect(-l, n);  
 	float a = texture(rough, uv).r * material.roughness;
 	float a2 = a * a;
 	float ndr = max(dot(n, ref), 0.0);
@@ -161,16 +164,20 @@ void main() {
 	vec3 view_dir = normalize(material.camera_pos - p);
 	float met = texture(metal, uv).r * material.metalness;
 
+	vec3 ref = reflect(-view_dir, nrm);
+	vec3 spec_col = texture(env_cube, ref).rgb;
+	vec3 amb_col = texture(env_cube, nrm).rgb;
+
 	vec3 diffuse =
 		diffuse_brdf(uv) *
 		(1.0 - met) *
 		cos_theta_i;
 	vec3 spec =
-		mix(1.0.xxx, col, met) *
-		specular_brdf(uv, light_dir, view_dir, nrm) *
+		mix(spec_col, col, met) *
+		specular_brdf(uv, ref, light_dir, view_dir, nrm) *
 		cos_theta_i;
 	vec3 ambient =
-		min(col, 0.05) *
+		min(amb_col, 0.05) *
 		texture(ao, uv).r;
 
 	colour = vec4(ambient + diffuse + spec, 1.0);
diff --git a/model.cpp b/model.cpp
index 778d945..dac6538 100644
--- a/model.cpp
+++ b/model.cpp
@@ -128,10 +128,12 @@ Asset* Model_Loader::load(
 		mesh.mvp_binding = shader->descriptor_binding("c_mvp");
 		mesh.mvp_binding_depth = depth_shader->descriptor_binding("c_mvp");
 		mesh.mat_binding = shader->descriptor_binding("material");
+		mesh.env_cube_binding = shader->descriptor_binding("env_cube");
 		mesh.mesh_binding = shader->binding_index("mesh");
 		assert(mesh.mvp_binding >= 0);
 		assert(mesh.mat_binding >= 0);
 		assert(mesh.mesh_binding >= 0);
+		assert(mesh.env_cube_binding >= 0);
 		pack_read(f, &vertex_size, 4);
 		pack_read(f, &mesh.count, 4);
 		pack_read(f, &vertex_count, 4);
@@ -330,6 +332,7 @@ void Model_Instance::render(
 	Device* dev,
 	Arena* a,
 	Render_Pass& pass,
+	Texture_Id env_cubemap,
 	Sampler_Id sampler
 ) {
 	int i, c = m->mesh_count;
@@ -382,6 +385,11 @@ void Model_Instance::render(
 				i * sizeof(MVP_Cbuffer),
 				sizeof(MVP_Cbuffer)
 			);
+			pb.texture(
+				mesh.env_cube_binding,
+				env_cubemap,
+				sampler
+			);
 		}
 		pb.cull(Cull_Mode::back);
 		pb.vertex_format(shader.vf);
@@ -433,12 +441,13 @@ void Model_Scene::render(
 	Device* dev,
 	Arena* a,
 	Render_Pass& pass,
+	Texture_Id env_cubemap,
 	Sampler_Id sampler
 ) {
 	int i;
 	Model_Instance* instance = instances;
 	for (i = 0; i < count; i++, instance++)
-		instance->render(dev, a, pass, sampler);
+		instance->render(dev, a, pass, env_cubemap, sampler);
 }
 
 void Model_Scene::destroy(Device* dev) {
diff --git a/model.hpp b/model.hpp
index 7b8f4fb..f21c35e 100644
--- a/model.hpp
+++ b/model.hpp
@@ -26,6 +26,7 @@ struct Model;
 struct Mesh {
 	int offset, vbo_offset, count;
 	int parent, mesh_binding, mvp_binding, mat_binding;
+	int env_cube_binding;
 	int mvp_binding_depth;
 	bool world_dirty;
 	m4f world, local;
@@ -99,6 +100,7 @@ struct Model_Instance {
 		Device* dev,
 		Arena* a,
 		Render_Pass& pass,
+		Texture_Id env_cubemap,
 		Sampler_Id sampler
 	);
 };
@@ -118,6 +120,7 @@ struct Model_Scene {
 		Device* dev,
 		Arena* a,
 		Render_Pass& pass,
+		Texture_Id env_cubemap,
 		Sampler_Id sampler
 	);
 };