Add VGUI HUD overlay drawing feature

Currently only supports Orange Box and Left 4 Dead branches. There's
quite a large amount of gamedata involved in making this work, and
figuring it out for the likes of Portal 2 doesn't seem like a major
priority at the moment.

1 files changed, 72 insertions, 0 deletions

diff --git a/src/hud.h b/src/hud.h
new file mode 100644
index 0000000..8ea0877
--- /dev/null
+++ b/src/hud.h
@@ -0,0 +1,72 @@
+/*
+ * Copyright © 2022 Matthew Wozniak <sirtomato999@gmail.com>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED “AS IS” AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
+ * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+ * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+ * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
+ * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#ifndef INC_HUD_H
+#define INC_HUD_H
+
+#include "event.h"
+#include "engineapi.h"
+#include "intdefs.h"
+
+/*
+ * Emitted when the game HUD is being drawn. Allows features to draw their own
+ * additional overlays atop the game's standard HUD.
+ */
+DECL_EVENT(HudPaint, void)
+
+/* Font style flags */
+#define HUD_FONT_ITALIC 1
+#define HUD_FONT_UNDERLINE 2
+#define HUD_FONT_STRIKE 4
+#define HUD_FONT_SYMBOL 8
+#define HUD_FONT_AA 16
+#define HUD_FONT_GAUSSBLUR 32
+#define HUD_FONT_ROTARY 64
+#define HUD_FONT_DROPSHADOW 128
+#define HUD_FONT_ADDITIVE 256
+#define HUD_FONT_OUTLINE 512
+#define HUD_FONT_CUSTOM 1024
+#define HUD_FONT_BITMAP 2048
+
+/* Gets a font handle by its name in sourcescheme.res. */
+ulong hud_getfont(const char *name, bool proportional);
+
+/* Sets the drawing pen colour for subsequent HUD drawing calls (below). */
+void hud_setcolour(struct rgba colour);
+
+/* Draws a rectangle on top of the HUD. */
+void hud_drawrect(int x0, int y0, int x1, int y1, struct rgba colour, bool fill);
+
+/* Draws a line on top of the HUD. */
+void hud_drawline(int x0, int y0, int x1, int y1, struct rgba colour);
+
+/* Draws an arbitrary series of lines between an array of points. */
+void hud_drawpolyline(int *xs, int *ys, int npoints, struct rgba colour);
+
+/* Draws text using a given font handle. */
+void hud_drawtext(ulong font, int x, int y, struct rgba colour, ushort *str,
+		int len);
+
+/* Returns the width and height of the game window in pixels. */
+void hud_screensize(int *width, int *height);
+
+/* Returns the height of a font, in pixels. */
+int hud_fontheight(ulong font);
+
+/* Returns the width of a font character, in pixels. */
+int hud_getcharwidth(ulong font, int ch);
+
+#endif