new home for set_colormap

2 files changed, 134 insertions, 0 deletions

diff --git a/Smoke/palette.c b/Smoke/palette.c
new file mode 100644
index 0000000..df24f04
--- /dev/null
+++ b/Smoke/palette.c
@@ -0,0 +1,114 @@
+#ifdef G_OS_WIN32
+#define WIN32_LEAN_AND_MEAN 1
+#include <windows.h>
+#endif
+
+
+#include <math.h>
+
+#include "funcs.h"
+#include "palette.h"
+
+
+//rainbow: Implements a color palette, mapping the scalar 'value' to a rainbow color RGB
+void rainbow(float value, float *R, float *G, float *B)
+{                          
+   const float dx = 0.8f;
+
+   if (value < 0) value = 0;
+   if (value > 1) value = 1;
+
+   value = (6 - 2 * dx) * value + dx;
+
+   *R = (float)max(0.0f, (3 - fabs(value - 4.0f) - fabs(value - 5.0f)) / 2.0f);
+   *G = (float)max(0.0f, (4 - fabs(value - 2.0f) - fabs(value - 4.0f)) / 2.0f);
+   *B = (float)max(0.0f, (3 - fabs(value - 1.0f) - fabs(value - 2.0f)) / 2.0f);
+}
+
+void colormap_fire(float value, float *R, float *G, float *B)
+{
+	/* Colormap Fire
+	 * A fire effect deals with two parts, first a drop from red to yellow (halfway)
+	 * during which time the Red component remains full e.g. 1. The Green component is
+	 * slowly added to turn the red into orange, and then yellow (R & G =Y). After this
+	 * point, the Red and Green component (e.g. yellow) have to drop simulataniously
+	 * to go from yellow down to black.
+	 */
+	*B = 0;
+	*G = 0;
+	*R = 0;
+
+	if (value <= (0.01)) {
+		/* whilst value is 0 - 0.5 both red and green equally change to create yellow */
+		*R = *G = value;
+	} else {
+		/* whilst value is 0.5 - 1 Red is always fully on while the Green component is
+		 * added in steps to go from red to orange to yellow.
+		 */
+		*G = 0.9f - value;
+		*R = 0.8f; // not 1, makes red deeper, more intense
+	}
+}
+
+//set_colormap: Sets three different types of colormaps
+struct color4f set_colormap(int colormap_sort, float vy, float alpha)
+{
+   float R, G, B;
+   struct color4f return_value;
+   const int NLEVELS = 7;
+
+//   vy *= olivers_color;
+//   vy = (float)(int)(vy);
+ //  vy /= olivers_color;
+
+   switch (colormap_sort)
+   {
+     case COLOR_BLACKWHITE:
+       R = G = B = vy;
+       break;
+     case COLOR_RAINBOW:
+       rainbow(vy,&R,&G,&B);
+       break;
+     case COLOR_BANDS:
+       vy *= NLEVELS; vy = (float)(int)(vy); vy/= NLEVELS; 
+	     rainbow(vy,&R,&G,&B);
+       break;
+     case COLOR_BLUE_GREEN_RED:
+       if  (vy < -0.1)
+       {
+         R = G = 0;
+         vy -= -0.1f;
+         vy /= 0.9f;
+         B = -vy;
+       }
+       else if (vy < 0.1)
+       {
+         R = B = 0;
+         vy += 0.1f;
+         vy /= 0.2f;
+         G = vy;
+       }
+       else
+       {
+         vy -= 0.1f;
+         vy /= 0.9f;
+         R = vy;
+         G = B = 0;
+       }
+       break;
+     case COLOR_WILRIK:
+       colormap_fire(vy, &R, &G, &B);
+       break;
+     case COLOR_OLIVER:
+       rainbow(vy, &R, &G, &B);
+       break;
+
+   }
+
+   return_value.r = R;
+   return_value.g = G;
+   return_value.b = B;
+   return_value.a = alpha;
+
+   return return_value;
+}
diff --git a/Smoke/palette.h b/Smoke/palette.h
new file mode 100644
index 0000000..497d9eb
--- /dev/null
+++ b/Smoke/palette.h
@@ -0,0 +1,20 @@
+#ifndef _PALETTE_H
+#define _PALETTE_H
+
+#define COLOR_BLACKWHITE 0
+#define COLOR_RAINBOW 1
+#define COLOR_BANDS 2
+#define COLOR_BLUE_GREEN_RED 3
+#define COLOR_WILRIK 4
+#define COLOR_OLIVER 5
+
+struct color4f {
+  float r;
+  float g;
+  float b;
+  float a;
+};
+
+struct color4f set_colormap(int colormap_sort, float vy, float alpha);
+
+#endif