From cb76c5137c30a6060b131d37a3befc4735db591e Mon Sep 17 00:00:00 2001
From: Lephenixnoir <sebastien.michelland@protonmail.com>
Date: Wed, 24 May 2023 09:53:12 +0200
Subject: [PATCH] lv1: slightly improve random generation

---
 CMakeLists.txt         |  1 +
 src/generator.h        | 14 +++++++++++-
 src/generator/gen1.cpp | 51 +++++++++++++++++++++++++-----------------
 src/generator/path.cpp | 22 ++++++++++++++++++
 src/settings.h         |  4 ++--
 5 files changed, 68 insertions(+), 24 deletions(-)
 create mode 100644 src/generator/path.cpp

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 913654b..c43accc 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -13,6 +13,7 @@ set(SOURCES
   src/generator/gen1.cpp
   src/generator/gen2.cpp
   src/generator/gen3.cpp
+  src/generator/path.cpp
   src/level.cpp
   src/log.cpp
   src/main.cpp
diff --git a/src/generator.h b/src/generator.h
index 7d9a8f6..a2f460c 100644
--- a/src/generator.h
+++ b/src/generator.h
@@ -4,6 +4,18 @@
 struct level;
 typedef struct level level_t;
 
+/* A utility structure holding data for path carver - a generator tool that
+   produces a random traversable path. */
+struct path
+{
+	path(int initial_pos);
+	void next(struct section *section);
+
+private:
+	int pos;
+	bool last_skipped;
+};
+
 struct generator
 {
 	virtual void generate(level_t *) = 0;
@@ -16,7 +28,7 @@ struct gen1 : public generator
 	void generate(level_t *) override;
 	~gen1() override = default;
 
-	int last_pos;
+	path paths[3];
 };
 
 struct gen2 : public generator
diff --git a/src/generator/gen1.cpp b/src/generator/gen1.cpp
index 2e54512..722bd16 100644
--- a/src/generator/gen1.cpp
+++ b/src/generator/gen1.cpp
@@ -3,32 +3,41 @@
 
 #define N PLATFORM_COUNT
 
-gen1::gen1() : last_pos{0}
+gen1::gen1(): paths{{0}, {N/3}, {N*2/3}}
 {
-	srand(0xc0ffee);
+    srand(0xc0ffee);
 }
 
 void gen1::generate(level_t *level)
 {
-	struct section section;
-	int r = rand() % 3;
+    int kind = rand() % 2;
+    int length = 2 + rand() % 6;
 
-	if(r == 0) {
-		for(int i = 0; i < N; i++)
-			section.platforms[i].type = PLATFORM_WHITE;
-	}
-	else if(r == 1) {
-		for(int i = 0; i < N; i++) {
-			auto t = (i % 2) ? PLATFORM_WHITE : PLATFORM_EMPTY;
-			section.platforms[i].type = t;
-		}
-	}
-	else if(r == 2) {
-		for(int i = 0; i < N; i++) {
-			auto t = (i % 2) ? PLATFORM_EMPTY : PLATFORM_WHITE;
-			section.platforms[i].type = t;
-		}
-	}
+    for(int k = 0; k < length; k++) {
+        struct section section;
+        for(int i = 0; i < N; i++)
+            section.platforms[i].type = PLATFORM_EMPTY;
 
-	level->section_buffer.push_back(section);
+        /* Kind #0: Only the random paths */
+        for(int i = 0; i < 3; i++)
+            this->paths[i].next(&section);
+
+        /* Kind #1: Also add some fixed blocks */
+        if(kind == 1) {
+            int r = rand() % 3;
+
+            if(r == 0 || r == 1) {
+                for(int i = 0; i < N; i++) {
+                    auto t = ((i ^ k) & 1) ? PLATFORM_WHITE : PLATFORM_EMPTY;
+                    section.platforms[i].type = t;
+                }
+            }
+            if(r == 2) {
+                for(int i = 0; i < N; i++)
+                    section.platforms[i].type = PLATFORM_WHITE;
+            }
+        }
+
+        level->section_buffer.push_back(section);
+    }
 }
diff --git a/src/generator/path.cpp b/src/generator/path.cpp
new file mode 100644
index 0000000..6766b70
--- /dev/null
+++ b/src/generator/path.cpp
@@ -0,0 +1,22 @@
+#include "../generator.h"
+#include "../level.h"
+
+path::path(int initial_pos):
+    pos {initial_pos}, last_skipped {true}
+{
+}
+
+void path::next(struct section *section)
+{
+    int skip = !this->last_skipped && (rand() % 4 == 0);
+
+    if(skip) {
+        this->last_skipped = true;
+    }
+    else {
+        int diff = rand() % 3 - 1;
+        section->platforms[this->pos].type = PLATFORM_WHITE;
+        this->pos = (this->pos + PLATFORM_COUNT + diff) % PLATFORM_COUNT;
+        this->last_skipped = false;
+    }
+}
diff --git a/src/settings.h b/src/settings.h
index d7fdd86..d219473 100644
--- a/src/settings.h
+++ b/src/settings.h
@@ -4,13 +4,13 @@
 /* Radius of the level cylinder, in world units. */
 #define LEVEL_RADIUS num(4.0)
 /* Section lengths, in world units. */
-#define SECTION_LENGTH num(4.0)
+#define SECTION_LENGTH num(3.0)
 /* Number of platforms in the world cylinder. */
 #define PLATFORM_COUNT 10
 /* Magnitude of the gravity field, locally (world units/s^2), when holding the
    jump button and when releasing it. */
 #define HOVERING_GRAVITY num(-1.25)
-#define FALLING_GRAVITY num(-6.0)
+#define FALLING_GRAVITY num(-8.0)
 /* Vertical speed granted when a jump starts (world units/s). */
 #define JUMP_THRUST num(1.5)