Add half z matrix projection functions

src/game/bootloader.cpp

@@ -454,7 +454,7 @@ void setup_rendering(game_context* ctx)
 	ctx->framebuffer_hdr_color->set_wrapping(texture_wrapping::clamp, texture_wrapping::clamp);
 	ctx->framebuffer_hdr_color->set_filters(texture_min_filter::linear, texture_mag_filter::linear);
 	ctx->framebuffer_hdr_color->set_max_anisotropy(0.0f);
-	ctx->framebuffer_hdr_depth = new texture_2d(viewport_dimensions[0], viewport_dimensions[1], pixel_type::uint_32, pixel_format::ds);
+	ctx->framebuffer_hdr_depth = new texture_2d(viewport_dimensions[0], viewport_dimensions[1], pixel_type::float_32, pixel_format::ds);
 	ctx->framebuffer_hdr_depth->set_wrapping(texture_wrapping::clamp, texture_wrapping::clamp);
 	ctx->framebuffer_hdr_depth->set_filters(texture_min_filter::linear, texture_mag_filter::linear);
 	ctx->framebuffer_hdr_depth->set_max_anisotropy(0.0f);
@@ -1179,7 +1179,7 @@ void setup_controls(game_context* ctx)
 	(
 		[ctx, time_scale]()
 		{
-			ctx->weather_system->set_time_scale(time_scale * 50.0f);
+			ctx->weather_system->set_time_scale(time_scale * 500.0f);
 		}
 	);
 	ctx->control_system->get_fast_forward_control()->set_deactivated_callback
@@ -1193,7 +1193,7 @@ void setup_controls(game_context* ctx)
 	(
 		[ctx, time_scale]()
 		{
-			ctx->weather_system->set_time_scale(time_scale * -50.0f);
+			ctx->weather_system->set_time_scale(time_scale * -500.0f);
 		}
 	);
 	ctx->control_system->get_rewind_control()->set_deactivated_callback

src/game/states/play-state.cpp

@@ -91,7 +91,7 @@ void play_state_enter(game_context* ctx)
 	sky_pass->set_sky_model(ctx->resource_manager->load<model>("sky-dome.mdl"));
 	
 	ctx->weather_system->set_coordinates(ctx->biome->coordinates);
-	ctx->weather_system->set_time(2020, 10, 1, 6, 0, 0, -7.0);
+	ctx->weather_system->set_time(2020, 6, 1, 5, 0, 0, -7.0);
 	ctx->weather_system->set_sky_palette(ctx->biome->sky_palette);
 	ctx->weather_system->set_sun_palette(ctx->biome->sun_palette);
 	ctx->weather_system->set_ambient_palette(ctx->biome->ambient_palette);

src/math/matrix-functions.hpp

@@ -166,7 +166,7 @@ template
 vector<T, 4> mul(const matrix<T, 4, 4>& m, const vector<T, 4>& v);
 
 /**
- * Creates an orthographic projection matrix.
+ * Creates an orthographic projection matrix which will transform the near and far clipping planes to `[-1, 1]`, respectively.
  *
  * @param left Signed distance to the left clipping plane.
  * @param right Signed distance to the right clipping plane.
@@ -179,6 +179,20 @@ vector mul(const matrix& m, const vector& v);
 template <class T>
 matrix<T, 4, 4> ortho(T left, T right, T bottom, T top, T z_near, T z_far);
 
+/**
+ * Creates an orthographic projection matrix which will transform the near and far clipping planes to `[0, 1]`, respectively.
+ *
+ * @param left Signed distance to the left clipping plane.
+ * @param right Signed distance to the right clipping plane.
+ * @param bottom Signed distance to the bottom clipping plane.
+ * @param top Signed distance to the top clipping plane.
+ * @param z_near Signed distance to the near clipping plane.
+ * @param z_far Signed distance to the far clipping plane.
+ * @return Orthographic projection matrix.
+ */
+template <class T>
+matrix<T, 4, 4> ortho_half_z(T left, T right, T bottom, T top, T z_near, T z_far);
+
 /**
  * Calculates the outer product of a pair of vectors.
  *
@@ -197,7 +211,7 @@ template
 matrix<T, 4, 4> outer_product(const vector<T, 4>& c, const vector<T, 4> r);
 
 /**
- * Creates a perspective projection matrix.
+ * Creates a perspective projection matrix which will transform the near and far clipping planes to `[-1, 1]`, respectively.
  *
  * @param vertical_fov Vertical field of view angle, in radians.
  * @param aspect_ratio Aspect ratio which determines the horizontal field of view.
@@ -208,6 +222,18 @@ matrix outer_product(const vector& c, const vector r);
 template <class T>
 matrix<T, 4, 4> perspective(T vertical_fov, T aspect_ratio, T z_near, T z_far);
 
+/**
+ * Creates a perspective projection matrix which will transform the near and far clipping planes to `[0, 1]`, respectively.
+ *
+ * @param vertical_fov Vertical field of view angle, in radians.
+ * @param aspect_ratio Aspect ratio which determines the horizontal field of view.
+ * @param z_near Distance to the near clipping plane.
+ * @param z_far Distance to the far clipping plane.
+ * @return Perspective projection matrix.
+ */
+template <class T>
+matrix<T, 4, 4> perspective_half_z(T vertical_fov, T aspect_ratio, T z_near, T z_far);
+
 /**
  * Resizes a matrix. Any new elements will be set to `1` if in the diagonal, and `0` otherwise.
  *
@@ -579,6 +605,18 @@ matrix ortho(T left, T right, T bottom, T top, T z_near, T z_far)
 		}};
 }
 
+template <class T>
+matrix<T, 4, 4> ortho_half_z(T left, T right, T bottom, T top, T z_near, T z_far)
+{
+	return
+		{{
+			 {T(2) / (right - left), T(0), T(0), T(0)},
+			 {T(0), T(2) / (top - bottom), T(0), T(0)},
+			 {T(0), T(0), T(-1) / (z_far - z_near), T(0)},
+			 {-((right + left) / (right - left)), -((top + bottom) / (top - bottom)), -z_near / (z_far - z_near), T(1)}
+		}};
+}
+
 template <class T>
 matrix<T, 2, 2> outer_product(const vector<T, 2>& c, const vector<T, 2>& r)
 {
@@ -622,11 +660,26 @@ matrix perspective(T vertical_fov, T aspect_ratio, T z_near, T z_far)
 		{{
 			 {f / aspect_ratio, T(0), T(0), T(0)},
 			 {T(0), f, T(0), T(0)},
-			 {T(0), T(0), (z_far + z_near) / (z_near - z_far), T(-1)},
+			 {T(0), T(0), (z_near + z_far) / (z_near - z_far), T(-1)},
 			 {T(0), T(0), (T(2) * z_near * z_far) / (z_near - z_far), T(0)}
 		}};
 }
 
+template <class T>
+matrix<T, 4, 4> perspective_half_z(T vertical_fov, T aspect_ratio, T z_near, T z_far)
+{
+	T half_fov = vertical_fov * T(0.5);
+	T f = std::cos(half_fov) / std::sin(half_fov);
+
+	return
+		{{
+			 {f / aspect_ratio, T(0), T(0), T(0)},
+			 {T(0), f, T(0), T(0)},
+			 {T(0), T(0), z_far / (z_near - z_far), T(-1)},
+			 {T(0), T(0), -(z_far * z_near) / (z_far - z_near), T(0)}
+		}};
+}
+
 template <std::size_t N1, std::size_t M1, class T, std::size_t N0, std::size_t M0>
 matrix<T, N1, M1> resize(const matrix<T, N0, M0>& m)
 {

src/renderer/passes/material-pass.cpp

@@ -113,6 +113,9 @@ void material_pass::render(render_context* context) const
 	glCullFace(GL_BACK);
 	glDisable(GL_STENCIL_TEST);
 	glStencilMask(0x00);
+	
+	// For half-z buffer
+	glDepthRange(-1.0f, 1.0f);
 
 	auto viewport = framebuffer->get_dimensions();
 	rasterizer->set_viewport(0, 0, std::get<0>(viewport), std::get<1>(viewport));
@@ -128,9 +131,10 @@ void material_pass::render(render_context* context) const
 	float4x4 model;
 	float4x4 model_view;
 	float3x3 normal_model_view;
-	
-
-
+	float2 clip_depth;
+	clip_depth[0] = context->camera->get_clip_near_tween().interpolate(context->alpha);
+	clip_depth[1] = context->camera->get_clip_far_tween().interpolate(context->alpha);
+	float log_depth_coef = 2.0f / std::log2(clip_depth[1] + 1.0f);
 
 
 	int active_material_flags = 0;
@@ -488,6 +492,10 @@ void material_pass::render(render_context* context) const
 			parameters->model_view_projection->upload(model_view_projection);
 		if (parameters->normal_model_view)
 			parameters->normal_model_view->upload(normal_model_view);
+		if (parameters->clip_depth)
+			parameters->clip_depth->upload(clip_depth);
+		if (parameters->log_depth_coef)
+			parameters->log_depth_coef->upload(log_depth_coef);
 
 		// Draw geometry
 		if (operation.instance_count)
@@ -533,6 +541,8 @@ const material_pass::parameter_set* material_pass::load_parameter_set(const shad
 	parameters->view_projection = program->get_input("view_projection");
 	parameters->model_view_projection = program->get_input("model_view_projection");
 	parameters->normal_model_view = program->get_input("normal_model_view");
+	parameters->clip_depth = program->get_input("clip_depth");
+	parameters->log_depth_coef = program->get_input("log_depth_coef");
 	parameters->ambient_light_count = program->get_input("ambient_light_count");
 	parameters->ambient_light_colors = program->get_input("ambient_light_colors");
 	parameters->point_light_count = program->get_input("point_light_count");

src/renderer/passes/material-pass.hpp

@@ -77,6 +77,8 @@ private:
 		const shader_input* view_projection;
 		const shader_input* model_view_projection;
 		const shader_input* normal_model_view;
+		const shader_input* clip_depth;
+		const shader_input* log_depth_coef;
 		
 		const shader_input* ambient_light_count;
 		const shader_input* ambient_light_colors;

src/renderer/passes/shadow-map-pass.cpp

@@ -107,6 +107,9 @@ void shadow_map_pass::render(render_context* context) const
 	// Disable face culling
 	glDisable(GL_CULL_FACE);
 	
+	// For half-z buffer
+	//glDepthRange(-1.0f, 1.0f);
+	
 	// Get camera
 	const ::camera& camera = *context->camera;
 	
@@ -137,7 +140,7 @@ void shadow_map_pass::render(render_context* context) const
 	float3 forward = light_transform.rotation * global_forward;
 	float3 up = light_transform.rotation * global_up;
 	float4x4 light_view = math::look_at(light_transform.translation, light_transform.translation + forward, up);
-	float4x4 light_projection = math::ortho(-1.0f, 1.0f, -1.0f, 1.0f, -1.0f, 1.0f);
+	float4x4 light_projection = math::ortho_half_z(-1.0f, 1.0f, -1.0f, 1.0f, -1.0f, 1.0f);
 	float4x4 light_view_projection = light_projection * light_view;
 	
 	// Get the camera's view matrix
@@ -161,7 +164,7 @@ void shadow_map_pass::render(render_context* context) const
 		// Calculate projection matrix for view camera subfrustum
 		const float subfrustum_near = split_distances[i];
 		const float subfrustum_far = split_distances[i + 1];
-		float4x4 subfrustum_projection = math::perspective(camera.get_fov(), camera.get_aspect_ratio(), subfrustum_near, subfrustum_far);
+		float4x4 subfrustum_projection = math::perspective_half_z(camera.get_fov(), camera.get_aspect_ratio(), subfrustum_near, subfrustum_far);
 		
 		// Calculate view camera subfrustum
 		view_frustum<float> subfrustum(subfrustum_projection * camera_view);
@@ -186,6 +189,7 @@ void shadow_map_pass::render(render_context* context) const
 		scale.x = 2.0f / (cropping_bounds.max_point.x - cropping_bounds.min_point.x);
 		scale.y = 2.0f / (cropping_bounds.max_point.y - cropping_bounds.min_point.y);
 		scale.z = 1.0f / (cropping_bounds.max_point.z - cropping_bounds.min_point.z);
+		//scale.z = 2.0f / (cropping_bounds.max_point.z - cropping_bounds.min_point.z);
 		
 		// Quantize scale
 		float scale_quantizer = 64.0f;
@@ -197,6 +201,7 @@ void shadow_map_pass::render(render_context* context) const
 		offset.x = (cropping_bounds.max_point.x + cropping_bounds.min_point.x) * scale.x * -0.5f;
 		offset.y = (cropping_bounds.max_point.y + cropping_bounds.min_point.y) * scale.y * -0.5f;
 		offset.z = -cropping_bounds.min_point.z * scale.z;
+		//offset.z = (cropping_bounds.max_point.z + cropping_bounds.min_point.z) * scale.z * -0.5f;
 
 		// Quantize offset
 		float half_shadow_map_resolution = static_cast<float>(shadow_map_resolution) * 0.5f;

src/scene/camera.cpp

@@ -93,7 +93,8 @@ float3 camera::unproject(const float3& window, const float4& viewport) const
 	float4 result;
 	result[0] = ((window[0] - viewport[0]) / viewport[2]) * 2.0f - 1.0f;
 	result[1] = ((window[1] - viewport[1]) / viewport[3]) * 2.0f - 1.0f;
-	result[2] = window[2] * 2.0f - 1.0f;
+	//result[2] = window[2] * 2.0f - 1.0f; z: [-1, 1]
+	result[2] = window[2]; // z: [0, 1]
 	result[3] = 1.0f;
 	
 	result = math::inverse(view_projection[1]) * result;
@@ -110,7 +111,7 @@ void camera::set_perspective(float fov, float aspect_ratio, float clip_near, flo
 	this->clip_near[1] = clip_near;
 	this->clip_far[1] = clip_far;
 
-	projection[1] = math::perspective(fov, aspect_ratio, clip_near, clip_far);
+	projection[1] = math::perspective_half_z(fov, aspect_ratio, clip_near, clip_far);
 	
 	// Recalculate view-projection matrix
 	view_projection[1] = projection[1] * view[1];