From 726dedafbc6d9b4a12ccf1a715f16459d7e7b1ef Mon Sep 17 00:00:00 2001
From: Ton Roosendaal <ton@blender.org>
Date: Tue, 2 Apr 2013 17:12:21 +0000
Subject: [PATCH] More Histogram fixes:

Sequencer histogram was calculating still badly, now it uses a per-color
component counter to calculate the levels (instead of counter for all)
---
 source/blender/blenkernel/intern/colortools.c | 16 ++++----
 .../editors/space_sequencer/sequencer_draw.c  |  2 +-
 .../space_sequencer/sequencer_scopes.c        | 39 +++++++++++--------
 3 files changed, 31 insertions(+), 26 deletions(-)

diff --git a/source/blender/blenkernel/intern/colortools.c b/source/blender/blenkernel/intern/colortools.c
index 9321141f4cc..04cc3cc6a09 100644
--- a/source/blender/blenkernel/intern/colortools.c
+++ b/source/blender/blenkernel/intern/colortools.c
@@ -1092,10 +1092,7 @@ void scopes_update(Scopes *scopes, ImBuf *ibuf, const ColorManagedViewSettings *
 	if (is_float)
 		rf = ibuf->rect_float;
 	else {
-		if (view_settings)
-			rc = (unsigned char *)IMB_display_buffer_acquire(ibuf, view_settings, display_settings, &cache_handle);
-		else
-			rc = (unsigned char *)ibuf->rect;
+		rc = (unsigned char *)IMB_display_buffer_acquire(ibuf, view_settings, display_settings, &cache_handle);
 	}
 	
 	if (ibuf->rect_float)
@@ -1178,11 +1175,12 @@ void scopes_update(Scopes *scopes, ImBuf *ibuf, const ColorManagedViewSettings *
 		if (bin_b[x]   > nb) nb = bin_b[x];
 		if (bin_a[x]   > na) na = bin_a[x];
 	}
-	divl = 1.0 / (double)nl;
-	diva = 1.0 / (double)na;
-	divr = 1.0 / (double)nr;
-	divg = 1.0 / (double)ng;
-	divb = 1.0 / (double)nb;
+	divl = nl ? 1.0 / (double)nl : 1.0;
+	diva = na ? 1.0 / (double)na : 1.0;
+	divr = nr ? 1.0 / (double)nr : 1.0;
+	divg = ng ? 1.0 / (double)ng : 1.0;
+	divb = nb ? 1.0 / (double)nb : 1.0;
+	
 	for (x = 0; x < 256; x++) {
 		scopes->hist.data_luma[x] = bin_lum[x] * divl;
 		scopes->hist.data_r[x] = bin_r[x] * divr;
diff --git a/source/blender/editors/space_sequencer/sequencer_draw.c b/source/blender/editors/space_sequencer/sequencer_draw.c
index 536832a2ff8..141af5d5ba4 100644
--- a/source/blender/editors/space_sequencer/sequencer_draw.c
+++ b/source/blender/editors/space_sequencer/sequencer_draw.c
@@ -896,7 +896,7 @@ static ImBuf *sequencer_make_scope(Scene *scene, ImBuf *ibuf, ImBuf *(*make_scop
 {
 	ImBuf *display_ibuf = IMB_dupImBuf(ibuf);
 	ImBuf *scope;
-
+	
 	IMB_colormanagement_imbuf_make_display_space(display_ibuf, &scene->view_settings,
 		                                             &scene->display_settings);
 
diff --git a/source/blender/editors/space_sequencer/sequencer_scopes.c b/source/blender/editors/space_sequencer/sequencer_scopes.c
index c8b70c0ce4a..79b50f2d3ae 100644
--- a/source/blender/editors/space_sequencer/sequencer_scopes.c
+++ b/source/blender/editors/space_sequencer/sequencer_scopes.c
@@ -531,7 +531,7 @@ BLI_INLINE int get_bin_float(float f)
 static ImBuf *make_histogram_view_from_ibuf_float(ImBuf *ibuf)
 {
 	ImBuf *rval = IMB_allocImBuf(515, 128, 32, IB_rect);
-	int n, c, x, y;
+	int nr, ng, nb, x, y;
 	float *src = ibuf->rect_float;
 
 	unsigned int bins[3][HIS_STEPS];
@@ -563,23 +563,30 @@ static ImBuf *make_histogram_view_from_ibuf_float(ImBuf *ibuf)
 		}
 	}
 
+	nr = nb = ng = 0;
+	for (x = 0; x < HIS_STEPS; x++) {
+		if (bins[0][x] > nr)
+			nr = bins[0][x];
+		if (bins[1][x] > ng)
+			ng = bins[1][x];
+		if (bins[2][x] > nb)
+			nb = bins[2][x];
+	}
+	
+	for (x = 0; x < HIS_STEPS; x++) {
+		if (nr) {
+			draw_histogram_bar(rval, x + 1, ((float) bins[0][x]) / nr, 0);
+		}
+		if (ng) {
+			draw_histogram_bar(rval, x + 1, ((float) bins[1][x]) / ng, 1);
+		}
+		if (nb) {
+			draw_histogram_bar(rval, x + 1, ((float) bins[2][x]) / nb, 2);
+		}
+	}
+	
 	draw_histogram_marker(rval, get_bin_float(0.0));
 	draw_histogram_marker(rval, get_bin_float(1.0));
-
-	n = 0;
-	for (c = 0; c < 3; c++) {
-		for (x = 0; x < HIS_STEPS; x++) {
-			if (bins[c][x] > n) {
-				n = bins[c][x];
-			}
-		}
-	}
-	for (c = 0; c < 3; c++) {
-		for (x = 0; x < HIS_STEPS; x++) {
-			draw_histogram_bar(rval, x + 1, (float) bins[c][x] / n, c);
-		}
-	}
-
 	wform_put_border((unsigned char *) rval->rect, rval->x, rval->y);
 	
 	return rval;