Add compass HUD element (#9312)

Co-authored-by: Jean-Patrick Guerrero <jeanpatrick.guerrero@gmail.com>
Co-authored-by: Pierre-Yves Rollo <dev@pyrollo.com>
Co-authored-by: SmallJoker <SmallJoker@users.noreply.github.com>

5 files changed, 175 insertions, 2 deletions

diff --git a/doc/lua_api.txt b/doc/lua_api.txt
index 08bdba03e..c81824163 100644
--- a/doc/lua_api.txt
+++ b/doc/lua_api.txt
@@ -1451,7 +1451,23 @@ Same as `image`, but does not accept a `position`; the position is instead deter
 * `world_pos`: World position of the waypoint.
 * `offset`: offset in pixels from position.
 
+### `compass`
 
+Displays an image oriented or translated according to current heading direction.
+
+* `size`: The size of this element. Negative values represent percentage
+  of the screen; e.g. `x=-100` means 100% (width).
+* `scale`: Scale of the translated image (used only for dir = 2 or dir = 3).
+* `text`: The name of the texture to use.
+* `alignment`: The alignment of the image.
+* `offset`: Offset in pixels from position.
+* `dir`: How the image is rotated/translated:
+  * 0 - Rotate as heading direction
+  * 1 - Rotate in reverse direction
+  * 2 - Translate as landscape direction
+  * 3 - Translate in reverse direction
+
+If translation is chosen, texture is repeated horizontally to fill the whole element.
 
 Representations of simple things
 ================================
@@ -7968,7 +7984,7 @@ Used by `Player:hud_add`. Returned by `Player:hud_get`.
 
     {
         hud_elem_type = "image",  -- See HUD element types
-        -- Type of element, can be "image", "text", "statbar", or "inventory"
+        -- Type of element, can be "image", "text", "statbar", "inventory" or "compass"
 
         position = {x=0.5, y=0.5},
         -- Left corner position of element
diff --git a/src/client/hud.cpp b/src/client/hud.cpp
index 2b347c1e0..d3038230c 100644
--- a/src/client/hud.cpp
+++ b/src/client/hud.cpp
@@ -114,6 +114,28 @@ Hud::Hud(gui::IGUIEnvironment *guienv, Client *client, LocalPlayer *player,
 	} else {
 		m_selection_material.MaterialType = video::EMT_SOLID;
 	}
+
+	// Prepare mesh for compass drawing
+	m_rotation_mesh_buffer.Vertices.set_used(4);
+	m_rotation_mesh_buffer.Indices.set_used(6);
+
+	video::SColor white(255, 255, 255, 255);
+	v3f normal(0.f, 0.f, 1.f);
+
+	m_rotation_mesh_buffer.Vertices[0] = video::S3DVertex(v3f(-1.f, -1.f, 0.f), normal, white, v2f(0.f, 1.f));
+	m_rotation_mesh_buffer.Vertices[1] = video::S3DVertex(v3f(-1.f,  1.f, 0.f), normal, white, v2f(0.f, 0.f));
+	m_rotation_mesh_buffer.Vertices[2] = video::S3DVertex(v3f( 1.f,  1.f, 0.f), normal, white, v2f(1.f, 0.f));
+	m_rotation_mesh_buffer.Vertices[3] = video::S3DVertex(v3f( 1.f, -1.f, 0.f), normal, white, v2f(1.f, 1.f));
+
+	m_rotation_mesh_buffer.Indices[0] = 0;
+	m_rotation_mesh_buffer.Indices[1] = 1;
+	m_rotation_mesh_buffer.Indices[2] = 2;
+	m_rotation_mesh_buffer.Indices[3] = 2;
+	m_rotation_mesh_buffer.Indices[4] = 3;
+	m_rotation_mesh_buffer.Indices[5] = 0;
+
+	m_rotation_mesh_buffer.getMaterial().Lighting = false;
+	m_rotation_mesh_buffer.getMaterial().MaterialType = video::EMT_TRANSPARENT_ALPHA_CHANNEL;
 }
 
 Hud::~Hud()
@@ -423,6 +445,54 @@ void Hud::drawLuaElements(const v3s16 &camera_offset)
 					core::rect<s32>(core::position2d<s32>(0,0), imgsize),
 					NULL, colors, true);
 				break; }
+			case HUD_ELEM_COMPASS: {
+				video::ITexture *texture = tsrc->getTexture(e->text);
+				if (!texture)
+					continue;
+
+				// Positionning :
+				v2s32 dstsize(e->size.X, e->size.Y);
+				if (e->size.X < 0)
+					dstsize.X = m_screensize.X * (e->size.X * -0.01);
+				if (e->size.Y < 0)
+					dstsize.Y = m_screensize.Y * (e->size.Y * -0.01);
+
+				if (dstsize.X <= 0 || dstsize.Y <= 0)
+					return; // Avoid zero divides
+
+				// Angle according to camera view
+				v3f fore(0.f, 0.f, 1.f);
+				scene::ICameraSceneNode *cam = RenderingEngine::get_scene_manager()->getActiveCamera();
+				cam->getAbsoluteTransformation().rotateVect(fore);
+				int angle = - fore.getHorizontalAngle().Y;
+
+				// Limit angle and ajust with given offset
+				angle = (angle + (int)e->number) % 360;
+
+				core::rect<s32> dstrect(0, 0, dstsize.X, dstsize.Y);
+				dstrect += pos + v2s32(
+								(e->align.X - 1.0) * dstsize.X / 2,
+								(e->align.Y - 1.0) * dstsize.Y / 2) +
+						v2s32(e->offset.X * m_hud_scaling, e->offset.Y * m_hud_scaling);
+
+				switch (e->dir) {
+				case HUD_COMPASS_ROTATE:
+					drawCompassRotate(e, texture, dstrect, angle);
+					break;
+				case HUD_COMPASS_ROTATE_REVERSE:
+					drawCompassRotate(e, texture, dstrect, -angle);
+					break;
+				case HUD_COMPASS_TRANSLATE:
+					drawCompassTranslate(e, texture, dstrect, angle);
+					break;
+				case HUD_COMPASS_TRANSLATE_REVERSE:
+					drawCompassTranslate(e, texture, dstrect, -angle);
+					break;
+				default:
+					break;
+				}
+
+				break; }
 			default:
 				infostream << "Hud::drawLuaElements: ignoring drawform " << e->type <<
 					" of hud element ID " << i << " due to unrecognized type" << std::endl;
@@ -430,6 +500,76 @@ void Hud::drawLuaElements(const v3s16 &camera_offset)
 	}
 }
 
+void Hud::drawCompassTranslate(HudElement *e, video::ITexture *texture,
+		const core::rect<s32> &rect, int angle)
+{
+	const video::SColor color(255, 255, 255, 255);
+	const video::SColor colors[] = {color, color, color, color};
+
+	// Compute source image scaling
+	core::dimension2di imgsize(texture->getOriginalSize());
+	core::rect<s32> srcrect(0, 0, imgsize.Width, imgsize.Height);
+
+	v2s32 dstsize(rect.getHeight() * e->scale.X * imgsize.Width / imgsize.Height,
+			rect.getHeight() * e->scale.Y);
+
+	// Avoid infinite loop
+	if (dstsize.X <= 0 || dstsize.Y <= 0)
+		return;
+
+	core::rect<s32> tgtrect(0, 0, dstsize.X, dstsize.Y);
+	tgtrect +=  v2s32(
+				(rect.getWidth() - dstsize.X) / 2,
+				(rect.getHeight() - dstsize.Y) / 2) +
+			rect.UpperLeftCorner;
+
+	int offset = angle * dstsize.X / 360;
+
+	tgtrect += v2s32(offset, 0);
+
+	// Repeat image as much as needed
+	while (tgtrect.UpperLeftCorner.X > rect.UpperLeftCorner.X)
+		tgtrect -= v2s32(dstsize.X, 0);
+
+	draw2DImageFilterScaled(driver, texture, tgtrect, srcrect, &rect, colors, true);
+	tgtrect += v2s32(dstsize.X, 0);
+
+	while (tgtrect.UpperLeftCorner.X < rect.LowerRightCorner.X) {
+		draw2DImageFilterScaled(driver, texture, tgtrect, srcrect, &rect, colors, true);
+		tgtrect += v2s32(dstsize.X, 0);
+	}
+}
+
+void Hud::drawCompassRotate(HudElement *e, video::ITexture *texture,
+		const core::rect<s32> &rect, int angle)
+{
+	core::dimension2di imgsize(texture->getOriginalSize());
+
+	core::rect<s32> oldViewPort = driver->getViewPort();
+	core::matrix4 oldProjMat = driver->getTransform(video::ETS_PROJECTION);
+	core::matrix4 oldViewMat = driver->getTransform(video::ETS_VIEW);
+
+	core::matrix4 Matrix;
+	Matrix.makeIdentity();
+	Matrix.setRotationDegrees(v3f(0.f, 0.f, angle));
+
+	driver->setViewPort(rect);
+	driver->setTransform(video::ETS_PROJECTION, core::matrix4());
+	driver->setTransform(video::ETS_VIEW, core::matrix4());
+	driver->setTransform(video::ETS_WORLD, Matrix);
+
+	video::SMaterial &material = m_rotation_mesh_buffer.getMaterial();
+	material.TextureLayer[0].Texture = texture;
+	driver->setMaterial(material);
+	driver->drawMeshBuffer(&m_rotation_mesh_buffer);
+
+	driver->setTransform(video::ETS_WORLD, core::matrix4());
+	driver->setTransform(video::ETS_VIEW, oldViewMat);
+	driver->setTransform(video::ETS_PROJECTION, oldProjMat);
+
+	// restore the view area
+	driver->setViewPort(oldViewPort);
+}
 
 void Hud::drawStatbar(v2s32 pos, u16 corner, u16 drawdir,
 		const std::string &texture, const std::string &bgtexture,
diff --git a/src/client/hud.h b/src/client/hud.h
index ba34d479d..cf83cb16e 100644
--- a/src/client/hud.h
+++ b/src/client/hud.h
@@ -95,6 +95,12 @@ private:
 
 	void drawItem(const ItemStack &item, const core::rect<s32> &rect, bool selected);
 
+	void drawCompassTranslate(HudElement *e, video::ITexture *texture,
+			const core::rect<s32> &rect, int way);
+
+	void drawCompassRotate(HudElement *e, video::ITexture *texture,
+			const core::rect<s32> &rect, int way);
+
 	float m_hud_scaling; // cached minetest setting
 	float m_scale_factor;
 	v3s16 m_camera_offset;
@@ -115,6 +121,8 @@ private:
 
 	video::SMaterial m_selection_material;
 
+	scene::SMeshBuffer m_rotation_mesh_buffer;
+
 	enum
 	{
 		HIGHLIGHT_BOX,
diff --git a/src/hud.cpp b/src/hud.cpp
index 4830c56a4..175701342 100644
--- a/src/hud.cpp
+++ b/src/hud.cpp
@@ -28,6 +28,7 @@ const struct EnumString es_HudElementType[] =
 	{HUD_ELEM_INVENTORY, "inventory"},
 	{HUD_ELEM_WAYPOINT,  "waypoint"},
 	{HUD_ELEM_IMAGE_WAYPOINT, "image_waypoint"},
+	{HUD_ELEM_COMPASS,   "compass"},
 	{0, NULL},
 };
 
diff --git a/src/hud.h b/src/hud.h
index e015baec1..0a6993c1b 100644
--- a/src/hud.h
+++ b/src/hud.h
@@ -60,7 +60,8 @@ enum HudElementType {
 	HUD_ELEM_STATBAR   = 2,
 	HUD_ELEM_INVENTORY = 3,
 	HUD_ELEM_WAYPOINT  = 4,
-	HUD_ELEM_IMAGE_WAYPOINT = 5
+	HUD_ELEM_IMAGE_WAYPOINT = 5,
+	HUD_ELEM_COMPASS   = 6
 };
 
 enum HudElementStat {
@@ -79,6 +80,13 @@ enum HudElementStat {
 	HUD_STAT_TEXT2,
 };
 
+enum HudCompassDir {
+	HUD_COMPASS_ROTATE = 0,
+	HUD_COMPASS_ROTATE_REVERSE,
+	HUD_COMPASS_TRANSLATE,
+	HUD_COMPASS_TRANSLATE_REVERSE,
+};
+
 struct HudElement {
 	HudElementType type;
 	v2f pos;