From ff43f035b152b522dbafd673bdb0367521505128 Mon Sep 17 00:00:00 2001
From: Andrew Golovashevich <landgrafhomyak@gmail.com>
Date: Thu, 20 Mar 2025 18:00:27 +0300
Subject: [PATCH] Applying distance to perspective projection

---
 programs/lab5/src/main.cpp        |  6 +++---
 programs/lab5/src/sprite_data.hpp | 18 ++++++++++--------
 2 files changed, 13 insertions(+), 11 deletions(-)

diff --git a/programs/lab5/src/main.cpp b/programs/lab5/src/main.cpp
index 34f7a34..a9c7f6f 100644
--- a/programs/lab5/src/main.cpp
+++ b/programs/lab5/src/main.cpp
@@ -22,7 +22,7 @@ namespace BGTU::ComputerGraphicsLabWork::Impl {
 #if 1
 		QApplication qApplication{argc, argv};
 
-		SpriteData::Provider sprites_data_custom{0.1, 0.1, 10};
+		SpriteData::Provider sprites_data_custom{0.1, 0.1, 0.5};
 
 		QMainWindow w{};
 
@@ -37,8 +37,8 @@ namespace BGTU::ComputerGraphicsLabWork::Impl {
 		QObject::connect(&kbd, &QtUtilities::KeyboardCatcherWidget::key_pressed_D, &sprites_data_custom, &SpriteData::Provider::inc_y_angle);
 		QObject::connect(&kbd, &QtUtilities::KeyboardCatcherWidget::key_pressed_S, &sprites_data_custom, &SpriteData::Provider::dec_x_angle);
 		QObject::connect(&kbd, &QtUtilities::KeyboardCatcherWidget::key_pressed_W, &sprites_data_custom, &SpriteData::Provider::inc_x_angle);
-		QObject::connect(&kbd, &QtUtilities::KeyboardCatcherWidget::key_pressed_PageDown, &sprites_data_custom, &SpriteData::Provider::dec_scale);
-		QObject::connect(&kbd, &QtUtilities::KeyboardCatcherWidget::key_pressed_PageUp, &sprites_data_custom, &SpriteData::Provider::inc_scale);
+		QObject::connect(&kbd, &QtUtilities::KeyboardCatcherWidget::key_pressed_PageDown, &sprites_data_custom, &SpriteData::Provider::dec_distance);
+		QObject::connect(&kbd, &QtUtilities::KeyboardCatcherWidget::key_pressed_PageUp, &sprites_data_custom, &SpriteData::Provider::inc_distance);
 		QObject::connect(&kbd, &QtUtilities::KeyboardCatcherWidget::key_pressed_P, &sprites_data_custom, &SpriteData::Provider::switch_projection);
 
 		SortSprite sprites_sort{sprites, sprites_count};
diff --git a/programs/lab5/src/sprite_data.hpp b/programs/lab5/src/sprite_data.hpp
index 2a8523a..32b2ae5 100644
--- a/programs/lab5/src/sprite_data.hpp
+++ b/programs/lab5/src/sprite_data.hpp
@@ -36,11 +36,11 @@ namespace BGTU::ComputerGraphicsLabWork::Impl {
 		QMutex sync;
 		double x_angle;
 		double y_angle;
-		double scale;
+		double distance;
 
 		double x_angle_step;
 		double y_angle_step;
-		double scale_step;
+		double distance_step;
 		bool is_projection_enabled;
 
 		RendererApi::VirtualVoxelPainter::visible_pixel_coordinate_fast_t w, h;
@@ -50,14 +50,14 @@ namespace BGTU::ComputerGraphicsLabWork::Impl {
 				double x_angle_step,
 				double y_angle_step,
 				double scale_step
-		) : x_angle{0}, y_angle{0}, scale{1}, x_angle_step{x_angle_step}, y_angle_step{y_angle_step}, scale_step{scale_step},
+		) : x_angle{0}, y_angle{0}, distance{0}, x_angle_step{x_angle_step}, y_angle_step{y_angle_step}, distance_step{scale_step},
 			w{0}, h{0}, is_projection_enabled{false} {}
 
 		SpriteData get_sprite_data() override {
 			this->sync.lock();
 			double radius = (((this->w < this->h) ? this->w : this->h) * 7 / 16.0);
 			auto projection = this->is_projection_enabled
-							  ? Utilities::Matrix4d::projection_central(-2, 2, -2, 2, 1, 9) * Utilities::Matrix4d::scale(1, 1, -1) * Utilities::Matrix4d::shift(0, 0, 7)
+							  ? Utilities::Matrix4d::projection_central(-1.5, 1.5, -1.5, 1.5, 1, 9) * Utilities::Matrix4d::scale(5, 5, -1) * Utilities::Matrix4d::shift(0, 0, 7 + this->distance)
 							  : Utilities::Matrix4d::projection_orto(-2, 2, -2, 2, -6, 2);
 			SpriteData cached{
 					Utilities::Matrix4d::shift(this->w / 2, this->h / 2, 0) * Utilities::Matrix4d::scale(radius) * projection * Utilities::Matrix4d::rotate_x(this->x_angle) * Utilities::Matrix4d::rotate_y(this->y_angle),
@@ -99,15 +99,17 @@ namespace BGTU::ComputerGraphicsLabWork::Impl {
 			this->sync.unlock();
 		}
 
-		void inc_scale() {
+		void inc_distance() {
 			this->sync.lock();
-			this->scale += this->scale_step;
+			this->distance += this->distance_step;
 			this->sync.unlock();
 		}
 
-		void dec_scale() {
+		void dec_distance() {
 			this->sync.lock();
-			this->scale -= this->scale_step;
+			this->distance -= this->distance_step;
+			if (this->distance < 0)
+				this->distance = 0;
 			this->sync.unlock();
 		}