From 353b4ed1c5d5edb2cf3fb33aed86c6c5ba5d6b3f Mon Sep 17 00:00:00 2001
From: Linus Probert <linus.probert@gmail.com>
Date: Fri, 3 Aug 2018 10:45:54 +0200
Subject: [PATCH] Adds raycasting debug

Next step is to actually implement the Bresenham Line Algorithm to make
line of sight and object shadowing a reality.
---
 CMakeLists.txt   |  1 +
 src/main.c       |  4 ++++
 src/roommatrix.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++
 src/roommatrix.h |  6 +++++-
 4 files changed, 56 insertions(+), 1 deletion(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index c133be0..233e894 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -185,6 +185,7 @@ target_link_libraries(breakhack
 	${SDL2_IMAGE_LIBRARY}
 	${SDL2_TTF_LIBRARY}
 	${SDL2_MIXER_LIBRARY}
+	m # We need the math library
 	)
 
 if (NOT PHYSFS_FOUND)
diff --git a/src/main.c b/src/main.c
index 82f3002..7becb4b 100644
--- a/src/main.c
+++ b/src/main.c
@@ -573,6 +573,10 @@ run_game_render(void)
 	}
 	pointer_render(gPointer, gCamera);
 
+#ifdef DEBUG
+	roommatrix_render_debug(gRoomMatrix, gCamera);
+#endif
+
 	SDL_RenderPresent(gRenderer);
 }
 
diff --git a/src/roommatrix.c b/src/roommatrix.c
index a2f2ec4..3969c1a 100644
--- a/src/roommatrix.c
+++ b/src/roommatrix.c
@@ -17,6 +17,7 @@
  */
 
 #include <stdlib.h>
+#include <math.h>
 #include "defines.h"
 #include "roommatrix.h"
 #include "util.h"
@@ -265,6 +266,51 @@ roommatrix_render_lightmap(RoomMatrix *matrix, Camera *cam)
 	}
 }
 
+#ifdef DEBUG
+static void
+draw_raycasts_from(int x, int y, Camera *cam)
+{
+	double length = 4*32;
+	double x1 = x * 32 + 16;
+	double y1 = y * 32 + 16;
+	double angle = 0;
+
+	while (angle < 360) {
+		double x2 = x1 + length * cos(angle);
+		double y2 = y1 + length * sin(angle);
+		//printf("Drawing line: %fx%f -> %fx%f\n", x1, y1, x2, y2);
+		SDL_RenderDrawLine(cam->renderer,
+				   (int) x1,
+				   (int) y1,
+				   (int) x2,
+				   (int) y2);
+		angle += 7.5;
+	}
+}
+
+void
+roommatrix_render_debug(RoomMatrix *rm, Camera *cam)
+{
+	SDL_SetRenderDrawColor(cam->renderer, 0, 0, 0, SDL_ALPHA_OPAQUE);
+	for (int i = 0; i < MAP_ROOM_HEIGHT; ++i) {
+		SDL_RenderDrawLine(cam->renderer, 0, i*32, MAP_ROOM_WIDTH*32, i*32);
+	}
+	for (int i = 0; i < MAP_ROOM_WIDTH; ++i) {
+		SDL_RenderDrawLine(cam->renderer, i*32, 0, i*32, MAP_ROOM_HEIGHT*32);
+	}
+
+	// Draw raycasts
+	SDL_SetRenderDrawColor(cam->renderer, 255, 255, 255, 100);
+	for (int i = 0; i < MAP_ROOM_WIDTH; ++i) {
+		for (int j = 0; j < MAP_ROOM_HEIGHT; ++j) {
+			if (rm->spaces[i][j].lightsource) {
+				draw_raycasts_from(i, j, cam);
+			}
+		}
+	}
+}
+#endif
+
 void roommatrix_destroy(RoomMatrix *m)
 {
 	// Clear the list but don't destroy the items
diff --git a/src/roommatrix.h b/src/roommatrix.h
index e676c9b..0128f8e 100644
--- a/src/roommatrix.h
+++ b/src/roommatrix.h
@@ -39,7 +39,7 @@ typedef struct {
 	bool occupied;
 	bool lethal;
 	bool lightsource;
-	unsigned int light;
+	int light;
 	Monster *monster;
 	Player *player;
 	LinkedList *items;
@@ -67,6 +67,10 @@ void roommatrix_render_mouse_square(RoomMatrix*, Camera*);
 
 void roommatrix_render_lightmap(RoomMatrix*, Camera*);
 
+#ifdef DEBUG
+void roommatrix_render_debug(RoomMatrix*, Camera*);
+#endif
+
 void roommatrix_destroy(RoomMatrix*);
 
 #endif // ROOMMATRIX_H_