1 files changed, 58 insertions, 10 deletions

diff --git a/src/main/engine/engine.c b/src/main/engine/engine.c
index e619dc7..8db206a 100644
--- a/src/main/engine/engine.c
+++ b/src/main/engine/engine.c
@@ -18,10 +18,12 @@
  */
 
 #include <stdio.h>
+#include <stdlib.h>
 #include <time.h>
 #include <GL/gl.h>
-#include "../ui/ui.h"
 #include "engine.h"
+#include "../ui/ui.h"
+#include "../util/list.h"
 
 #ifdef X11
 #include <X11/Xlib.h>
@@ -34,6 +36,12 @@ static float ystep;
 static int width;
 static int height;
 
+static list_t *lines = NULL;
+
+typedef struct Line {
+	int x1, y1, x2, y2;
+} Line;
+
 typedef struct Engine {
 	void (*draw_frame)();
 } Engine;
@@ -57,16 +65,29 @@ engine_init(int w, int h)
 
 	xstep = RANGE_GL / (float) w;
 	ystep = RANGE_GL / (float) h;
+
+	lines = list_create();
+}
+
+static Line *
+engine_new_line(int x1, int y1, int x2, int y2)
+{
+	Line *line = malloc(sizeof(Line));
+	line->x1 = x1;
+	line->y1 = y1;
+	line->x2 = x2;
+	line->y2 = y2;
+
+	return line;
 }
 
 void
 engine_draw_line(int x1, int y1, int x2, int y2)
 {
-	float _x1 = x1 * xstep - 1; float _y1 = (height - y1) * ystep - 1;
-	float _x2 = x2 * xstep - 1; float _y2 = (height - y2) * ystep - 1;
-
-	glVertex2f(_x1, _y1);
-	glVertex2f(_x2, _y2);
+	if (lines != NULL) {
+		Line *line = engine_new_line(x1, y1, x2, y2);
+		list_add(lines, line);
+	}
 }
 
 static void
@@ -83,6 +104,34 @@ engine_calculate_fps()
 }
 
 static void
+render_line(Line *line)
+{
+	float _x1 = line->x1 * xstep - 1; float _y1 = (height - line->y1) * ystep - 1;
+	float _x2 = line->x2 * xstep - 1; float _y2 = (height - line->y2) * ystep - 1;
+
+	glVertex2f(_x1, _y1);
+	glVertex2f(_x2, _y2);
+}
+
+static void
+draw_lines()
+{
+	if (lines == NULL || lines->size <= 0) return;
+
+	glLineWidth(5.0f);
+	glBegin(GL_LINES);
+	glColor3f(1.0f, 1.0f, 0.0f); /* Yellow */
+
+	list_node_t *current = lines->head;
+	do {
+		render_line((Line *) current->data);
+		current = current->next;
+	} while (current != NULL);
+
+	glEnd();
+}
+
+static void
 draw_frames()
 {
 	glClearColor(0.0f, 0.0f, 0.2f, 1.0f);
@@ -91,15 +140,14 @@ draw_frames()
 	glEnable(GL_BLEND);
 	glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
 
-	engine.draw_frame();
+	draw_lines();
+
 	engine_calculate_fps();
 }
 
 void
-engine_loop(void (*draw_frame)())
+engine_loop(void)
 {
-	engine.draw_frame = draw_frame;
-
 	ui_set_loop_listener(draw_frames);
 
 	/* FPS calculation */