File prboom-hbar-gradient.diff of Package dsda-doom

From bef62d87d8de7236d2a6b306c588440b885f579b Mon Sep 17 00:00:00 2001
From: Jan Engelhardt <jengelh@inai.de>
Date: Wed, 1 May 2013 09:53:49 +0200
Subject: [PATCH] Implement color gradient for health bar

I drew inspiration from the gradient bars from Fire Fight.
---
 prboom2/src/gl_intern.h | 11 +--------
 prboom2/src/gl_main.c   | 52 ++++++++++++++++++++++++-----------------
 2 files changed, 31 insertions(+), 32 deletions(-)

Index: dsda-doom-0.28.0/prboom2/src/gl_intern.h
===================================================================
--- dsda-doom-0.28.0.orig/prboom2/src/gl_intern.h
+++ dsda-doom-0.28.0/prboom2/src/gl_intern.h
@@ -211,18 +211,9 @@ typedef struct
   float light;
 } GLShadow;
 
-typedef enum
-{
-  health_bar_null,
-  health_bar_red,
-  health_bar_yellow,
-  health_bar_green,
-} health_bar_color_t;
-
 typedef struct
 {
-  health_bar_color_t color;
-
+  float cr, cg;
   float x1, x2, x3;
   float z1, z2, z3;
   float y;
Index: dsda-doom-0.28.0/prboom2/src/gl_main.c
===================================================================
--- dsda-doom-0.28.0.orig/prboom2/src/gl_main.c
+++ dsda-doom-0.28.0/prboom2/src/gl_main.c
@@ -2032,24 +2032,41 @@ static void gld_DrawSprite(GLSprite *spr
 static void gld_AddHealthBar(mobj_t* thing, GLSprite *sprite)
 {
   bool all_shoot = dsda_ShowHealthBarsForShootables();
-  int init_color = all_shoot ? health_bar_green : health_bar_null;
   bool show_bar  = all_shoot ?
                    thing->flags & MF_SHOOTABLE :
                    (thing->flags & (MF_COUNTKILL | MF_CORPSE)) == MF_COUNTKILL;
+  /*
+   * These were called "health_bar_red", "health_bar_yellow" and
+   * "health_bar_green", respectively, in prboom-plus. I have given
+   * them some better names. —j.eng
+   */
+  static const int orange_ramp_end     = 50;
+  static const int chartreuse_ramp_end = 99;
+  static const int green_end           = 100;
 
   if (thing->health > 0 && show_bar)
   {
     GLHealthBar hbar;
     int health_percent = thing->health * 100 / P_MobjSpawnHealth(thing);
+    int yr = chartreuse_ramp_end - orange_ramp_end;
 
-    hbar.color = init_color;
-    if (health_percent <= 50)
-      hbar.color = health_bar_red;
-    else if (health_percent <= 99)
-      hbar.color = health_bar_yellow;
+    hbar.cr = -1;
+    if (!all_shoot && health_percent == 100) {
+    } else if (health_percent <= 0) {
+      hbar.cr = 1;
+      hbar.cg = 0;
+    } else if (health_percent <= orange_ramp_end) {
+      hbar.cr = 1;
+      hbar.cg = yr == 0 ? 0 : (float)health_percent / yr;
+    } else if (health_percent <= chartreuse_ramp_end) {
+      hbar.cr = yr == 0 ? 1 : (float)(chartreuse_ramp_end - health_percent) / yr;
+      hbar.cg = 1;
+    } else if (health_percent <= green_end) {
+      hbar.cr = 0;
+      hbar.cg = 1;
+    }
 
-    if (hbar.color != health_bar_null)
-    {
+    if (hbar.cr >= 0) {
       float sx2 = (float)thing->radius / 2.0f / MAP_SCALE;
       float sx1 = sx2 - (float)health_percent * (float)thing->radius / 100.0f / MAP_SCALE;
       float sx3 = -sx2;
@@ -2069,17 +2086,10 @@ static void gld_AddHealthBar(mobj_t* thi
   }
 }
 
-static GLfloat health_bar_rgb[][3] = {
-  [health_bar_null]   = { 0.0f, 0.0f, 0.0f },
-  [health_bar_red]    = { 1.0f, 0.0f, 0.0f },
-  [health_bar_yellow] = { 1.0f, 1.0f, 0.0f },
-  [health_bar_green]  = { 0.0f, 1.0f, 0.0f },
-};
-
 static void gld_DrawHealthBars(void)
 {
   int i, count;
-  int color = health_bar_null;
+  float cr = -1, cg = -1;
 
   count = gld_drawinfo.num_items[GLDIT_HBAR];
   if (count > 0)
@@ -2090,12 +2100,10 @@ static void gld_DrawHealthBars(void)
     for (i = count - 1; i >= 0; i--)
     {
       GLHealthBar *hbar = gld_drawinfo.items[GLDIT_HBAR][i].item.hbar;
-      if (hbar->color != color)
-      {
-        color = hbar->color;
-        glColor4f(health_bar_rgb[color][0],
-                  health_bar_rgb[color][1],
-                  health_bar_rgb[color][2], 1.0f);
+      if (hbar->cr != cr || hbar->cg != cg) {
+        cr = hbar->cr;
+        cg = hbar->cg;
+        glColor4f(cr, cg, 0, 1);
       }
 
       glVertex3f(hbar->x1, hbar->y, hbar->z1);