From 0d2150483270880b467a766aa447e60bd5c04810 Mon Sep 17 00:00:00 2001
From: cirdan <cirdansw@gmail.com>
Date: Fri, 3 Mar 2017 18:07:53 +0100
Subject: [PATCH] Add GlyphPos for a visual run glyph and its position

Add a new struct ParagraphLayouter::GlyphPos to hold a
glyph id and its position in a visual run and a method
ParagraphLayouter::VisualRun::GetGlyphPos to retrieve the
GlyphPos for a given glyph index in a visual run, and use
them from DrawLayoutLine.
---
 src/gfx.cpp      | 15 +++++++--------
 src/gfx_layout.h | 25 +++++++++++++++++++++++++
 2 files changed, 32 insertions(+), 8 deletions(-)

diff --git a/src/gfx.cpp b/src/gfx.cpp
index 25db95f16..5ccace8bf 100644
--- a/src/gfx.cpp
+++ b/src/gfx.cpp
@@ -433,23 +433,22 @@ static int DrawLayoutLine (const ParagraphLayouter::Line *line,
 		draw_shadow = colour != TC_BLACK && (colour & TC_NO_SHADE) == 0 && fc->GetDrawGlyphShadow();
 
 		for (int i = 0; i < run->GetGlyphCount(); i++) {
-			GlyphID glyph = run->GetGlyphs()[i];
-
+			ParagraphLayouter::GlyphPos gp;
 			/* Not a valid glyph (empty) */
-			if (glyph == 0xFFFF) continue;
+			if (!run->GetGlyphPos (&gp, i)) continue;
 
-			int begin_x = (int)run->GetPositions()[i * 2]     + left - offset_x;
-			int end_x   = (int)run->GetPositions()[i * 2 + 2] + left - offset_x  - 1;
-			int top     = (int)run->GetPositions()[i * 2 + 1] + y;
+			int begin_x = gp.x0 + left - offset_x;
+			int end_x   = gp.x1 + left - offset_x  - 1;
+			int top     = gp.y + y;
 
 			/* Truncated away. */
 			if (truncation && (begin_x < min_x || end_x > max_x)) continue;
 
-			const Sprite *sprite = fc->GetGlyph(glyph);
+			const Sprite *sprite = fc->GetGlyph (gp.glyph);
 			/* Check clipping (the "+ 1" is for the shadow). */
 			if (begin_x + sprite->x_offs > dpi_right || begin_x + sprite->x_offs + sprite->width /* - 1 + 1 */ < dpi_left) continue;
 
-			if (draw_shadow && (glyph & SPRITE_GLYPH) == 0) {
+			if (draw_shadow && (gp.glyph & SPRITE_GLYPH) == 0) {
 				SetColourRemap(TC_BLACK);
 				GfxMainBlitter (dpi, sprite, begin_x + 1, top + 1, BM_COLOUR_REMAP);
 				SetColourRemap(colour);
diff --git a/src/gfx_layout.h b/src/gfx_layout.h
index b5cbfe4af..7a7850785 100644
--- a/src/gfx_layout.h
+++ b/src/gfx_layout.h
@@ -27,6 +27,12 @@ struct FontBase {
 
 /** Namespace for paragraph layout-related types. */
 namespace ParagraphLayouter {
+	/** A glyph and the position where it goes. */
+	struct GlyphPos {
+		int x0, x1, y;
+		GlyphID glyph;
+	};
+
 	/** Visual run contains data about the bit of text with the same font. */
 	class VisualRun {
 	public:
@@ -35,6 +41,25 @@ namespace ParagraphLayouter {
 		virtual int GetGlyphCount() const = 0;
 		virtual const GlyphID *GetGlyphs() const = 0;
 		virtual const float *GetPositions() const = 0;
+
+		/**
+		 * Get the glyph and position for a glyph.
+		 * @param gp Struct to receive the data.
+		 * @param i Index of the glyph whose data to get.
+		 * @return Whether the glyph is valid (non-empty).
+		 */
+		bool GetGlyphPos (GlyphPos *gp, int i) const
+		{
+			GlyphID glyph = this->GetGlyphs()[i];
+			if (glyph == 0xFFFF) return false;
+
+			gp->glyph = glyph;
+			const float *pos = this->GetPositions();
+			gp->x0 = pos[i * 2];
+			gp->x1 = pos[i * 2 + 2];
+			gp->y  = pos[i * 2 + 1];
+			return true;
+		}
 	};
 
 	/** A single line worth of VisualRuns. */
-- 
2.11.4.GIT