pke: font centering tweaks handling char padding

1 files changed, 53 insertions, 4 deletions

diff --git a/src/font.cpp b/src/font.cpp
index d368b5a..2296466 100644
--- a/src/font.cpp
+++ b/src/font.cpp
@@ -112,10 +112,43 @@ float FontType_Inner_LookAheadWordLength(const FontType *const ft, const FontRen
 	return ret;
 }
 
+float FontType_Inner_LookAheadWordLength_NoPadding(const FontType *const ft, const FontRender *const fr, uint32_t index, float font_glyph_spacing, uint32_t *char_count = nullptr) {
+	uint32_t i;
+	float ret = 0;
+	FontGlyphChar *fgc;
+	for (i = index; i < fr->n_glyphs; ++i) {
+		fgc = &ft->glyphs[fr->glyph_indices[i]];
+		if (PK_HAS_FLAG(fgc->flags, FONT_GLYPH_CHAR_FLAGS_WHITESPACE) == true) {
+			break;
+		}
+		if (PK_HAS_FLAG(fgc->flags, FONT_GLYPH_CHAR_FLAGS_NEW_LINE) == true) {
+			break;
+		}
+		ret += fgc->advance * font_glyph_spacing;
+		if (i == index) {
+			// if -x, makes word larger
+			// if +x, makes word shorter
+			ret -= fgc->plane_bounds.x * font_glyph_spacing;
+		}
+	}
+	if (i != index) {
+		fgc = &ft->glyphs[fr->glyph_indices[i-1]];
+		ret -= (fgc->advance - fgc->plane_bounds.z) * font_glyph_spacing;
+	}
+	if (char_count != nullptr) {
+		*char_count = i - index;
+	}
+	return ret;
+}
+
 float FontType_Inner_LookAheadLineLength(const FontType *const ft, const FontRender *const fr, const uint32_t index, float font_glyph_spacing, uint32_t *char_count = nullptr) {
 	uint32_t i, ii;
 	float sz, ret = 0;
+	bool front_whitespace = true;
 	FontGlyphChar *fgc, *fgc2;
+	// When centering, we want to burn white-space characters:
+	//  at the front.
+	//  at the back.
 	for (i = index; i < fr->n_glyphs; ++i) {
 		fgc = &ft->glyphs[fr->glyph_indices[i]];
 		if (PK_HAS_FLAG(fgc->flags, FONT_GLYPH_CHAR_FLAGS_NEW_LINE) == true) {
@@ -127,16 +160,18 @@ float FontType_Inner_LookAheadLineLength(const FontType *const ft, const FontRen
 			}
 			break;
 		}
-		// we want to burn white-space characters at the front and at the back
 		if (PK_HAS_FLAG(fgc->flags, FONT_GLYPH_CHAR_FLAGS_WHITESPACE) == true) {
+			if (front_whitespace == true && PK_HAS_FLAG(fr->settings.surface_area_type_flags, FONT_RENDER_SURFACE_AREA_TYPE_FLAGS_CENTER_HORIZONTAL)) {
+				// burn white-spacing at the front
+				continue;
+			}
 			sz = fgc->advance * font_glyph_spacing;
 			if (ret + sz > fr->settings.surface_area_size.x) {
 				break;
 			}
 			ret += sz;
-			// burn the front - but only if we wrapped
 			fgc2 = nullptr;
-			if (i != 0) {
+			if (index != 0) {
 				fgc2 = &ft->glyphs[fr->glyph_indices[i-1]];
 				if (!PK_HAS_FLAG(fgc2->flags, FONT_GLYPH_CHAR_FLAGS_NEW_LINE)) {
 					fgc2 = nullptr;
@@ -156,6 +191,12 @@ float FontType_Inner_LookAheadLineLength(const FontType *const ft, const FontRen
 		// On the last word, not subtracting 1 causes the char_count to be off-by-one
 		i += ii-1;
 		ret += sz;
+		if (front_whitespace == true) {
+			// if -x, makes line larger
+			// if +x, makes line shorter
+			ret -= fgc->plane_bounds.x * font_glyph_spacing;
+		}
+		front_whitespace = false;
 	}
 	// If we are at the end of a line:
 	// Burn all white-space until we have a non-white-space
@@ -168,7 +209,8 @@ float FontType_Inner_LookAheadLineLength(const FontType *const ft, const FontRen
 			ii += 1;
 			continue;
 		}
-		ret += (fgc->plane_bounds.z - fgc->plane_bounds.x) * font_glyph_spacing;
+		// literal right edge of the char
+		ret += fgc->plane_bounds.z * font_glyph_spacing;
 		break;
 	}
 	if (char_count != nullptr) {
@@ -316,6 +358,9 @@ bool FontType_Inner_CalcTransforms(const FontType *ft, FontRender *fr, FontInsta
 					cursor_head = (fr->settings.surface_area_size.x - line_length) / 2.0;
 				}
 			}
+			if (first_word_of_line == true) {
+				cursor_head -= fgc->plane_bounds.x * font_glyph_spacing;
+			}
 		}
 		first_word_of_line = false;
 		new_word = false;
@@ -332,6 +377,10 @@ bool FontType_Inner_CalcTransforms(const FontType *ft, FontRender *fr, FontInsta
 		scale *= glm::vec3(glyph_size.x / (float)Extent.width, glyph_size.y / (float)Extent.height, 1.0);
 
 		// move to appropriate position + char placement
+		// Reminder that we are converting -1,1 positioning to screen-space.
+		// This means that we have to shift by half the width and half the height
+		//  in order to position the box correctly (glyph_size).
+		//  ; Without this, the character would be OOB on the left and/or top.
 
 		// ((val) - (width/2)) / (width/2)
 		// box position