1 files changed, 106 insertions, 0 deletions
diff --git a/graymap.c b/graymap.c
new file mode 100644
index 0000000..c44347c
--- /dev/null
+++ b/graymap.c
@@ -0,0 +1,106 @@
+#include "graymap.h"
+#include "common_types.h"
+#include <stdlib.h>
+
+graymap_t create_graymap(int w, int h)
+{
+	graymap_t rv;
+	rv.w = -1;
+	rv.h = -1;
+	rv.data = (double*) malloc(sizeof(double) * w * h);
+	if(rv.data == NULL)
+		return rv;
+	rv.w = w;
+	rv.h = h;
+	return rv;
+}
+
+void destroy_graymap(graymap_t* gm)
+{
+	free(gm->data);
+	gm->w = gm->h = -1;
+}
+
+void clear_graymap(graymap_t* gm, double grayval)
+{
+	int limit = gm->w * gm->h;
+	int i;
+	double* data_p = gm->data;
+	for(i = 0; i < limit; ++i, ++data_p)
+		(*data_p) = grayval;
+}
+
+void set_pix_graymap(graymap_t* gm, int x, int y, double gray)
+{
+	GM_PIX((*gm),x,y) = gray;
+}
+
+double get_pix_graymap(graymap_t* gm, int x, int y)
+{
+	return GM_PIX(*gm,x,y);
+}
+
+void blit_graymaps(graymap_t* src, graymap_t* dst, int src_x, int src_y,
+ int dst_x, int dst_y, int w, int h)
+{
+	if(src_x + w >= src->w)
+		w = src->w - src_x;
+	if(src_y + h >= src->h)
+		h = src->h - src_y;
+	if(dst_x + w >= dst->w)
+		w = dst->w - dst_x;
+	if(dst_y + h >= dst->h)
+		h = dst->h - dst_y;
+	int x,y;
+	for(y = 0; y < h; ++y)
+		for(x = 0; x < w; ++x)
+			GM_PIX(*dst,dst_x+x, dst_y+y) = GM_PIX(*src, src_x+x, src_y+y);
+}
+
+color_t get_palette_color(double grayval, color_t* pal_cols, double* pal_grays,
+ int pal_n)
+{
+	color_t rv;
+	rv.r = rv.g = rv.b = rv.a = .0;
+	int index;
+	double factor1, factor2;
+	BOOL found = FALSE;
+	/* find the index number */
+	for(index = 0; index < ( pal_n - 1 ); ++index)
+	{
+		if((grayval >= pal_grays[index]) && (grayval <= pal_grays[index+1]))
+		{
+			found = TRUE;
+			break;
+		}
+	}
+	
+	if(!found)
+		return rv;
+	
+	/* Calculate factors */
+	factor1 = (pal_grays[index+1] - grayval ) /
+	 ( pal_grays[index+1] -pal_grays[index] );
+	factor2 = 1.0 - factor1;
+	
+	/* Calculate color */
+	rv.r = ( pal_cols[index].r * factor1 ) +
+	 ( pal_cols[index+1].r * factor2 );
+	rv.g = ( pal_cols[index].g * factor1 ) +
+	 ( pal_cols[index+1].g * factor2 );
+	rv.b = ( pal_cols[index].b * factor1 ) +
+	 ( pal_cols[index+1].b * factor2 );
+	rv.a = ( pal_cols[index].a * factor1 ) +
+	 ( pal_cols[index+1].a * factor2 );
+	return rv;
+}
+
+color_t mkcol(double r, double g, double b, double a)
+{
+	color_t rv;
+	rv.r = r;
+	rv.g = g;
+	rv.b = b;
+	rv.a = a;
+	return rv;
+}