1 files changed, 52 insertions, 2 deletions

diff --git a/source/blender/imbuf/intern/imageprocess.c b/source/blender/imbuf/intern/imageprocess.c
index 92b8dd8c724..26dd0f2977a 100644
--- a/source/blender/imbuf/intern/imageprocess.c
+++ b/source/blender/imbuf/intern/imageprocess.c
@@ -104,7 +104,7 @@ void bicubic_interpolation_color(struct ImBuf *in, unsigned char outI[4], float
 		BLI_bicubic_interpolation_fl(in->rect_float, outF, in->x, in->y, 4, u, v);
 	}
 	else {
-		BLI_bicubic_interpolation_char((unsigned char*) in->rect, outI, in->x, in->y, 4, u, v);
+		BLI_bicubic_interpolation_char((unsigned char *) in->rect, outI, in->x, in->y, 4, u, v);
 	}
 }
 
@@ -130,7 +130,7 @@ void bilinear_interpolation_color(struct ImBuf *in, unsigned char outI[4], float
 		BLI_bilinear_interpolation_fl(in->rect_float, outF, in->x, in->y, 4, u, v);
 	}
 	else {
-		BLI_bilinear_interpolation_char((unsigned char*) in->rect, outI, in->x, in->y, 4, u, v);
+		BLI_bilinear_interpolation_char((unsigned char *) in->rect, outI, in->x, in->y, 4, u, v);
 	}
 }
 
@@ -327,3 +327,53 @@ void IMB_processor_apply_threaded(int buffer_lines, int handle_size, void *init_
 
 	MEM_freeN(handles);
 }
+
+/* Alpha-under */
+
+void IMB_alpha_under_color_float(float *rect_float, int x, int y, float backcol[3])
+{
+	int a = x * y;
+	float *fp = rect_float;
+
+	while (a--) {
+		if (fp[3] == 0.0f) {
+			copy_v3_v3(fp, backcol);
+		}
+		else {
+			float mul = 1.0f - fp[3];
+
+			fp[0] += mul * backcol[0];
+			fp[1] += mul * backcol[1];
+			fp[2] += mul * backcol[2];
+		}
+
+		fp[3] = 1.0f;
+
+		fp += 4;
+	}
+}
+
+void IMB_alpha_under_color_byte(unsigned char *rect, int x, int y, float backcol[3])
+{
+	int a = x * y;
+	unsigned char *cp = rect;
+
+	while (a--) {
+		if (cp[3] == 0) {
+			cp[0] = backcol[0] * 255;
+			cp[1] = backcol[1] * 255;
+			cp[2] = backcol[2] * 255;
+		}
+		else {
+			int mul = 255 - cp[3];
+
+			cp[0] = (cp[0] * cp[3] >> 8) + mul * backcol[0] / 255;
+			cp[1] = (cp[1] * cp[3] >> 8) + mul * backcol[1] / 255;
+			cp[2] = (cp[2] * cp[3] >> 8) + mul * backcol[2] / 255;
+		}
+
+		cp[3] = 255;
+
+		cp += 4;
+	}
+}