camera composition guides:

 removed diagonal golden rule (not very common), added harmonious triangle and golden triangle options.

3 files changed, 69 insertions, 38 deletions

diff --git a/source/blender/editors/space_view3d/view3d_draw.c b/source/blender/editors/space_view3d/view3d_draw.c
index 40a38d7f78c..4ef02243cd5 100644
--- a/source/blender/editors/space_view3d/view3d_draw.c
+++ b/source/blender/editors/space_view3d/view3d_draw.c
@@ -921,7 +921,7 @@ void view3d_calc_camera_border(Scene *scene, ARegion *ar, RegionView3D *rv3d, Vi
 	}
 }
 
-static void drawviewborder_grid3(float x1, float x2, float y1, float y2, float fac, char diagonal)
+static void drawviewborder_grid3(float x1, float x2, float y1, float y2, float fac)
 {
 	float x3, y3, x4, y4;
 
@@ -931,46 +931,63 @@ static void drawviewborder_grid3(float x1, float x2, float y1, float y2, float f
 	y4= y1 + (1.0f - fac) * (y2-y1);
 
 	glBegin(GL_LINES);
-	switch(diagonal) {
-	case '\0':
-		glVertex2f(x1, y3);
-		glVertex2f(x2, y3);
+	glVertex2f(x1, y3);
+	glVertex2f(x2, y3);
 
-		glVertex2f(x1, y4);
-		glVertex2f(x2, y4);
+	glVertex2f(x1, y4);
+	glVertex2f(x2, y4);
 
-		glVertex2f(x3, y1);
-		glVertex2f(x3, y2);
+	glVertex2f(x3, y1);
+	glVertex2f(x3, y2);
 
-		glVertex2f(x4, y1);
-		glVertex2f(x4, y2);
-		break;
-	case 'H': /* hoz */
-		glVertex2f(x1, y1);
-		glVertex2f(x2, y4);
+	glVertex2f(x4, y1);
+	glVertex2f(x4, y2);
+	glEnd();
+}
+
+/* harmonious triangle */
+static void drawviewborder_triangle(float x1, float x2, float y1, float y2, const char golden, const char dir)
+{
+	float ofs;
+	float w= x2 - x1;
+	float h= y2 - y1;
+
+	glBegin(GL_LINES);
+	if(w > h) {
+		if(golden) {
+			ofs = w * (1.0f-(1.0f/1.61803399));
+		}
+		else {
+			ofs = h * (h / w);
+		}
+		if(dir == 'B') SWAP(float, y1, y2);
 
-		glVertex2f(x1, y3);
+		glVertex2f(x1, y1);
 		glVertex2f(x2, y2);
 
 		glVertex2f(x2, y1);
-		glVertex2f(x1, y4);
+		glVertex2f(x1 + (w - ofs), y2);
 
-		glVertex2f(x2, y3);
 		glVertex2f(x1, y2);
-		break;
-	case 'V': /* vert */
-		glVertex2f(x1, y1);
-		glVertex2f(x4, y2);
+		glVertex2f(x1 + ofs, y1);
+	}
+	else {
+		if(golden) {
+			ofs = h * (1.0f-(1.0f/1.61803399));
+		}
+		else {
+			ofs = w * (w / h);
+		}
+		if(dir == 'B') SWAP(float, x1, x2);
 
-		glVertex2f(x3, y1);
+		glVertex2f(x1, y1);
 		glVertex2f(x2, y2);
 
-		glVertex2f(x1, y2);
-		glVertex2f(x4, y1);
-
-		glVertex2f(x3, y2);
 		glVertex2f(x2, y1);
-		break;
+		glVertex2f(x1, y1 + ofs);
+
+		glVertex2f(x1, y2);
+		glVertex2f(x2, y1 + (h - ofs));
 	}
 	glEnd();
 }
@@ -1083,22 +1100,32 @@ static void drawviewborder(Scene *scene, ARegion *ar, View3D *v3d)
 
 		if (ca->dtx & CAM_DTX_THIRDS) {
 			UI_ThemeColorBlendShade(TH_WIRE, TH_BACK, 0.25, 0);
-			drawviewborder_grid3(x1, x2, y1, y2, 1.0f/3.0f, '\0');
+			drawviewborder_grid3(x1, x2, y1, y2, 1.0f/3.0f);
 		}
 
 		if (ca->dtx & CAM_DTX_GOLDEN) {
 			UI_ThemeColorBlendShade(TH_WIRE, TH_BACK, 0.25, 0);
-			drawviewborder_grid3(x1, x2, y1, y2, 1.0f-(1.0f/1.61803399), '\0');
+			drawviewborder_grid3(x1, x2, y1, y2, 1.0f-(1.0f/1.61803399));
+		}
+
+		if (ca->dtx & CAM_DTX_GOLDEN_TRI_A) {
+			UI_ThemeColorBlendShade(TH_WIRE, TH_BACK, 0.25, 0);
+			drawviewborder_triangle(x1, x2, y1, y2, 0, 'A');
+		}
+
+		if (ca->dtx & CAM_DTX_GOLDEN_TRI_B) {
+			UI_ThemeColorBlendShade(TH_WIRE, TH_BACK, 0.25, 0);
+			drawviewborder_triangle(x1, x2, y1, y2, 0, 'B');
 		}
 
-		if (ca->dtx & CAM_DTX_GOLDEN_DIAG_H) {
+		if (ca->dtx & CAM_DTX_HARMONY_TRI_A) {
 			UI_ThemeColorBlendShade(TH_WIRE, TH_BACK, 0.25, 0);
-			drawviewborder_grid3(x1, x2, y1, y2, 1.0f-(1.0f/1.61803399), 'H');
+			drawviewborder_triangle(x1, x2, y1, y2, 1, 'A');
 		}
 
-		if (ca->dtx & CAM_DTX_GOLDEN_DIAG_V) {
+		if (ca->dtx & CAM_DTX_HARMONY_TRI_B) {
 			UI_ThemeColorBlendShade(TH_WIRE, TH_BACK, 0.25, 0);
-			drawviewborder_grid3(x1, x2, y1, y2, 1.0f-(1.0f/1.61803399), 'V');
+			drawviewborder_triangle(x1, x2, y1, y2, 1, 'B');
 		}
 
 		if (ca->flag & CAM_SHOWTITLESAFE) {
diff --git a/source/blender/makesdna/DNA_camera_types.h b/source/blender/makesdna/DNA_camera_types.h
index d64b72c6f40..952b4e799b5 100644
--- a/source/blender/makesdna/DNA_camera_types.h
+++ b/source/blender/makesdna/DNA_camera_types.h
@@ -76,8 +76,10 @@ typedef struct Camera {
 #define CAM_DTX_CENTER_DIAG		2
 #define CAM_DTX_THIRDS			4
 #define CAM_DTX_GOLDEN			8
-#define CAM_DTX_GOLDEN_DIAG_H	16
-#define CAM_DTX_GOLDEN_DIAG_V	32
+#define CAM_DTX_GOLDEN_TRI_A	16
+#define CAM_DTX_GOLDEN_TRI_B	32
+#define CAM_DTX_HARMONY_TRI_A	64
+#define CAM_DTX_HARMONY_TRI_B	128
 
 /* flag */
 #define CAM_SHOWLIMITS	1
diff --git a/source/blender/makesrna/intern/rna_camera.c b/source/blender/makesrna/intern/rna_camera.c
index 14a2f27bd8c..089c8c44943 100644
--- a/source/blender/makesrna/intern/rna_camera.c
+++ b/source/blender/makesrna/intern/rna_camera.c
@@ -72,8 +72,10 @@ void RNA_def_camera(BlenderRNA *brna)
 		{CAM_DTX_CENTER_DIAG, "CENTER_DIAGONAL", 0, "Center Diagonal", ""},
 		{CAM_DTX_THIRDS, "THIRDS", 0, "Thirds", ""},
 		{CAM_DTX_GOLDEN, "GOLDEN", 0, "Golden", ""},
-		{CAM_DTX_GOLDEN_DIAG_H, "GOLDEN_DIAGONAL_H", 0, "Golden Diagonal Hoz", ""},
-		{CAM_DTX_GOLDEN_DIAG_V, "GOLDEN_DIAGONAL_V", 0, "Golden Diagonal Vert", ""},
+		{CAM_DTX_GOLDEN_TRI_A, "GOLDEN_TRIANGLE_A", 0, "Golden Triangle A", ""},
+		{CAM_DTX_GOLDEN_TRI_B, "GOLDEN_TRIANGLE_B", 0, "Golden Triangle B", ""},
+		{CAM_DTX_HARMONY_TRI_A, "HARMONY_TRIANGLE_A", 0, "Harmonious Triangle A", ""},
+		{CAM_DTX_HARMONY_TRI_B, "HARMONY_TRIANGLE_B", 0, "Harmonious Triangle B", ""},
 		{0, NULL, 0, NULL, NULL}};
 	static EnumPropertyItem prop_lens_unit_items[] = {
 		{0, "MILLIMETERS", 0, "Millimeters", ""},