Introduced frustum culling, learned how to correctly spell frustum

Renderer/Renderer.cpp

@@ -8,6 +8,7 @@
 #include <Memory/Memory.hpp>
 
 #include <util/Timer.hpp>
+#include <util/geo.hpp>
 
 #include <Renderer/Pipeline.hpp>
 #include <Renderer/Shader.hpp>
@@ -18,6 +19,8 @@
 
 #include <UI/UI.hpp>
 
+
+
 using namespace std::string_literals;
 
 Renderer::Renderer(Window& win) : win(win) {
@@ -338,7 +341,7 @@ void Renderer::draw() {
 
 	const auto p = glm::perspective(glm::radians(90.0f), static_cast<float>(sz.width) / static_cast<float>(sz.height), 0.01f, 2000.0f);
 
-	uniform_buffer->upload(UniformData {
+	auto uni = UniformData{
 		.view = cam.view(),
 		.proj = p,
 		.time = time,
@@ -346,7 +349,11 @@ void Renderer::draw() {
 		.viewport = glm::vec2(viewport.width, viewport.y),
 		.tess_factor = tess_factor,
 		.tess_edge_size = tess_edge_size,
-	});
+	};
+
+	std::memcpy(uni.frustum, frustum(p * uni.view).data(), sizeof(uni.frustum));
+
+	uniform_buffer->upload(uni);
 
 	command_buffer->bind(*terrain_pipeline);
 	command_buffer->command_buffer.setViewport(0, viewport);

Renderer/UniformBuffer.hpp

@@ -18,6 +18,7 @@ struct UniformData {
 	float pad2;
 	glm::vec3 cam_pos;
 	float pad3;
+	glm::vec4 frustum[6];
 	glm::vec2 viewport;
 	float tess_factor;
 	float tess_edge_size;

Resources/Texture.hpp

@@ -27,7 +27,7 @@ struct Texture {
 			.binding = binding,
 			.descriptorType = vk::DescriptorType::eCombinedImageSampler,
 			.descriptorCount = 1,
-			.stageFlags = vk::ShaderStageFlagBits::eFragment | vk::ShaderStageFlagBits::eTessellationEvaluation,
+			.stageFlags = vk::ShaderStageFlagBits::eFragment | vk::ShaderStageFlagBits::eTessellationControl | vk::ShaderStageFlagBits::eTessellationEvaluation,
 			.pImmutableSamplers = nullptr,
 		};
 	}

assets/shaders/terrain.frag

@@ -10,6 +10,7 @@ layout (set = 0, binding = 0) uniform Matrices {
 	mat4 proj;
 	float time;
 	vec3 cam_pos;
+	vec4 frustum[6];
 	vec2 viewport;
 	float tess_factor;
 	float tess_edge_size;
@@ -23,5 +24,5 @@ void main() {
 	float r = length(light_pos-pos);
 	float t = clamp(dot(L, norm), 0.0, 1.0) * 20.0/(r*r);
 
-	FragColor = vec4(norm * texture(tex, texCoord).xyz + t, 1.0);
+	FragColor = vec4(1.0);
 }

assets/shaders/terrain.tesc

@@ -6,6 +6,7 @@ layout (set = 0, binding = 0) uniform Matrices {
 	mat4 proj;
 	float time;
 	vec3 cam_pos;
+	vec4 frustum[6];
 	vec2 viewport;
 	float tess_factor;
 	float tess_edge_size;
@@ -45,22 +46,39 @@ float screen_space_tess(vec4 p0, vec4 p1) {
 	return clamp(distance(clip0, clip1) / tess_edge_size * tess_factor, 1.0, 64.0);
 }
 
+bool frustum_culling() {
+	/* square root of patch size */
+	const float r = 8.0f;
+	/* ensure this is consistent with tese shader */
+	vec4 fpos = gl_in[gl_InvocationID].gl_Position;
+	fpos.y += 15.0 * textureLod(heightmap, texCoord[0], 0.0).r;
+	
+	for(int i = 0; i < 6; i++) {
+		if(dot(fpos, frustum[i]) + r < 0.0)
+			return false;
+	}
+	return true;
+}
+
 void main() {
 
 	if(gl_InvocationID == 0) {
+		/* perform frustum culling */
+		if(frustum_culling()) {
 			gl_TessLevelOuter[0] = screen_space_tess(gl_in[3].gl_Position, gl_in[0].gl_Position);
 			gl_TessLevelOuter[1] = screen_space_tess(gl_in[0].gl_Position, gl_in[1].gl_Position);
 			gl_TessLevelOuter[2] = screen_space_tess(gl_in[1].gl_Position, gl_in[2].gl_Position);
 			gl_TessLevelOuter[3] = screen_space_tess(gl_in[2].gl_Position, gl_in[3].gl_Position);
 			gl_TessLevelInner[0] = mix(gl_TessLevelOuter[0], gl_TessLevelOuter[3], 0.5);
 			gl_TessLevelInner[1] = mix(gl_TessLevelOuter[2], gl_TessLevelOuter[1], 0.5);
-		
-		/*gl_TessLevelOuter[0] = tess_factor;
-		gl_TessLevelOuter[1] = tess_factor;
-		gl_TessLevelOuter[2] = tess_factor;
-		gl_TessLevelOuter[3] = tess_factor;
-		gl_TessLevelInner[0] = mix(gl_TessLevelOuter[0], gl_TessLevelOuter[3], 0.5);
-		gl_TessLevelInner[1] = mix(gl_TessLevelOuter[2], gl_TessLevelOuter[1], 0.5);*/
+		} else {
+			gl_TessLevelOuter[0] = 0.0;
+			gl_TessLevelOuter[1] = 0.0;
+			gl_TessLevelOuter[2] = 0.0;
+			gl_TessLevelOuter[3] = 0.0;
+			gl_TessLevelInner[0] = 0.0;
+			gl_TessLevelInner[1] = 0.0;
+		}
 	}
 
 	gl_out[gl_InvocationID].gl_Position = gl_in[gl_InvocationID].gl_Position;

assets/shaders/terrain.tese

@@ -5,6 +5,7 @@ layout (set = 0, binding = 0) uniform Matrices {
 	mat4 proj;
 	float time;
 	vec3 cam_pos;
+	vec4 frustum[6];
 	vec2 viewport;
 	float tess_factor;
 	float tess_edge_size;
@@ -40,7 +41,7 @@ void main() {
 	vec4 pos2 = mix(gl_in[3].gl_Position, gl_in[2].gl_Position, gl_TessCoord.x);
 
 	vec4 fpos = mix(pos1, pos2, gl_TessCoord.y);
-	fpos.y += 15.0 * texture(heightmap, _texCoord).r; //+ cos(fpos.x*fpos.y);
+	fpos.y += 15.0 * texture(heightmap, _texCoord).r;
 
 	_pos = fpos.xyz;
 	gl_Position = proj * view * fpos;

assets/shaders/terrain.vert

@@ -12,6 +12,7 @@ layout (set = 0, binding = 0) uniform Matrices {
 	mat4 proj;
 	float time;
 	vec3 cam_pos;
+	vec4 frustum[6];
 	vec2 viewport;
 	float tess_factor;
 	float tess_edge_size;

util/geo.hpp

@@ -0,0 +1,17 @@
+#pragma once
+
+#include <glm/glm.hpp>
+#include <array>
+
+/* extracts frustum from projection matrix */
+static std::array<glm::vec4, 6> frustum(const glm::mat4& mat) {
+	/* Left, Right, Top, Bottom, Back, Front */
+	std::array<glm::vec4, 6> ret;
+
+	for (size_t i = 0; i < 3; i++)
+		for (size_t j = 0; j < 4; j++)
+			ret[i * 2][j] = mat[j].w + mat[j][i],
+			ret[i * 2 + 1][j] = mat[j].w - mat[j][i];
+
+	return ret;
+}