pke: ui box text center first-pass

3 files changed, 97 insertions, 28 deletions

diff --git a/src/font.cpp b/src/font.cpp
index 3dba635..3204f58 100644
--- a/src/font.cpp
+++ b/src/font.cpp
@@ -108,6 +108,47 @@ float FontType_Inner_LookAheadWordLength(const FontType *const ft, const FontRen
 	return ret;
 }
 
+float FontType_Inner_LookAheadLineLength(const FontType *const ft, const FontRender *const fr, uint32_t index, float font_glyph_spacing) {
+	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_NEW_LINE) == true) {
+			break;
+		}
+		if (ret + (fgc->advance * font_glyph_spacing) > fr->settings.surface_area_size.x) {
+			break;
+		}
+		ret += fgc->advance * font_glyph_spacing;
+	}
+	return ret;
+}
+
+float FontType_Inner_LookAheadLineCount(const FontType *const ft, const FontRender *const fr, const uint32_t index) {
+	uint32_t i, u;
+	float ret = 1;
+	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_NEW_LINE) == true) {
+			if (i+1 < fr->n_glyphs) {
+				if (fgc->unicode == 10) {
+					u = 11;
+				} else {
+					u = 10;
+				}
+				// handle \r\n
+				if (ft->glyphs[fr->glyph_indices[i+1]].unicode == u) {
+					i += 1; // burn
+				}
+			}
+			ret += 1;
+		}
+	}
+	return ret;
+}
+
 void FontType_Inner_CalcTransforms(const FontType *ft, FontRender *fr, FontInstanceBufferItem *ptr_dst) {
 	assert(ft != nullptr);
 	assert(fr != nullptr);
@@ -117,7 +158,7 @@ void FontType_Inner_CalcTransforms(const FontType *ft, FontRender *fr, FontInsta
 	bool new_word = true;
 	uint32_t i;
 	float font_glyph_spacing;
-	float cursor_head, line_index, line_height;
+	float cursor_head, line_index, line_height, line_length, line_offset;
 	glm::vec2 glyph_size;
 	glm::vec3 translate;
 	glm::vec3 scale;
@@ -129,12 +170,31 @@ void FontType_Inner_CalcTransforms(const FontType *ft, FontRender *fr, FontInsta
 	// Trying to get pixel-perfect rendering with mannequin-7.
 	// Everything is now sized and positioned correctly.
 	// However, there is a ghost layer around the letter.
+	// 2025-09-22 - JCB
+	// I believe this is because of how the anti-aliasing works.
+	// When this gets re-visited, attempt to disable anti-aliasing entirely.
+	// Suggestion: require min distance to be 0?
+	// Also note that I don't think we're doing any calculations to make sure the
+	//  left-most pixel is exact to the Extent (screen size).
 
 	font_glyph_spacing = ft->spacing.em_size * fr->settings.char_scale;
 	cursor_head = 0;
 	line_index = 0;
+	line_offset = 0;
 	line_height = font_glyph_spacing * ft->spacing.line_height * fr->settings.line_height_scale;
 
+	line_length = FontType_Inner_LookAheadLineLength(ft, fr, 0, font_glyph_spacing);
+	if (PK_HAS_FLAG(fr->settings.surface_area_type_flags, FONT_RENDER_SURFACE_AREA_TYPE_FLAGS_CENTER_HORIZONTAL)) {
+		cursor_head = (fr->settings.surface_area_size.x - line_length) / 2.0;
+	}
+	if (PK_HAS_FLAG(fr->settings.surface_area_type_flags, FONT_RENDER_SURFACE_AREA_TYPE_FLAGS_CENTER_VERTICAL)) {
+		float text_height = FontType_Inner_LookAheadLineCount(ft, fr, 0) * line_height;
+		// TODO
+		// This is wrong but I'm not sure how/why.
+		// Mathematically it should be ` / 2.0`.
+		line_offset += (fr->settings.surface_area_size.y - text_height) / 4.0;
+	}
+
 	for (i = 0; i < fr->n_glyphs; ++i) {
 		translate = glm::vec3(0);
 		scale = glm::vec3(1);
@@ -149,7 +209,12 @@ void FontType_Inner_CalcTransforms(const FontType *ft, FontRender *fr, FontInsta
 				}
 			}
 			line_index += 1;
-			cursor_head = 0;
+			line_length = FontType_Inner_LookAheadLineLength(ft, fr, i+1, font_glyph_spacing);
+			if (PK_HAS_FLAG(fr->settings.surface_area_type_flags, FONT_RENDER_SURFACE_AREA_TYPE_FLAGS_CENTER_HORIZONTAL)) {
+				cursor_head = (fr->settings.surface_area_size.x - line_length) / 2.0;
+			} else {
+				cursor_head = 0;
+			}
 			continue;
 		}
 		if (PK_HAS_FLAG(fgc->flags, FONT_GLYPH_CHAR_FLAGS_WHITESPACE) == true) {
@@ -172,7 +237,13 @@ void FontType_Inner_CalcTransforms(const FontType *ft, FontRender *fr, FontInsta
 			float word_width = FontType_Inner_LookAheadWordLength(ft, fr, i, font_glyph_spacing);
 			if (cursor_head + word_width > fr->settings.surface_area_size.x) {
 				line_index += 1;
-				cursor_head = 0;
+				line_length = FontType_Inner_LookAheadLineLength(ft, fr, i+1, font_glyph_spacing);
+
+				if (PK_HAS_FLAG(fr->settings.surface_area_type_flags, FONT_RENDER_SURFACE_AREA_TYPE_FLAGS_CENTER_HORIZONTAL)) {
+					cursor_head = (fr->settings.surface_area_size.x - line_length) / 2.0;
+				} else {
+					cursor_head = 0;
+				}
 			}
 			new_word = false;
 		}
@@ -207,6 +278,7 @@ void FontType_Inner_CalcTransforms(const FontType *ft, FontRender *fr, FontInsta
 		translate.y = fr->settings.surface_area_pos.y;
 		// baseline - current line (+1 to not draw above the box)
 		translate.y += ((line_index + 1) * line_height);
+		translate.y += line_offset;
 		// places the top line of the glyph on the baseline
 		translate.y += (font_glyph_spacing / 2.0) + (glyph_size.y / 2.0);
 		// move glyph to the height relative to the baseline (cursor)
diff --git a/src/font.hpp b/src/font.hpp
index 75035b8..fce99a0 100644
--- a/src/font.hpp
+++ b/src/font.hpp
@@ -16,28 +16,25 @@ TypeSafeInt_H(FontRenderIndex, uint16_t, 0xFFFF);
 TypeSafeInt_H(FONT_GLYPH_CHAR_FLAG, uint8_t, 0xFF);
 TypeSafeInt_H(FONT_RENDER_SURFACE_AREA_TYPE_FLAG, uint8_t, 0xFF);
 
-constexpr FONT_GLYPH_CHAR_FLAG FONT_GLYPH_CHAR_FLAGS_NONE
-        = FONT_GLYPH_CHAR_FLAG((0 << 0));
-constexpr FONT_GLYPH_CHAR_FLAG FONT_GLYPH_CHAR_FLAGS_CONTROL
-        = FONT_GLYPH_CHAR_FLAG((1 << 0));
-constexpr FONT_GLYPH_CHAR_FLAG FONT_GLYPH_CHAR_FLAGS_WHITESPACE
-        = FONT_GLYPH_CHAR_FLAG((1 << 1));
-constexpr FONT_GLYPH_CHAR_FLAG FONT_GLYPH_CHAR_FLAGS_ALIGN_ADVANCE
-        = FONT_GLYPH_CHAR_FLAG((1 << 2));
-constexpr FONT_GLYPH_CHAR_FLAG FONT_GLYPH_CHAR_FLAGS_NEW_LINE
-        = FONT_GLYPH_CHAR_FLAG((1 << 3));
+const FONT_GLYPH_CHAR_FLAG FONT_GLYPH_CHAR_FLAGS_NONE
+    = FONT_GLYPH_CHAR_FLAG(0u);
+const FONT_GLYPH_CHAR_FLAG FONT_GLYPH_CHAR_FLAGS_CONTROL
+    = FONT_GLYPH_CHAR_FLAG((1u << 0));
+const FONT_GLYPH_CHAR_FLAG FONT_GLYPH_CHAR_FLAGS_WHITESPACE
+    = FONT_GLYPH_CHAR_FLAG((1u << 1));
+const FONT_GLYPH_CHAR_FLAG FONT_GLYPH_CHAR_FLAGS_ALIGN_ADVANCE
+    = FONT_GLYPH_CHAR_FLAG((1u << 2));
+const FONT_GLYPH_CHAR_FLAG FONT_GLYPH_CHAR_FLAGS_NEW_LINE
+    = FONT_GLYPH_CHAR_FLAG((1u << 3));
 
-constexpr FONT_RENDER_SURFACE_AREA_TYPE_FLAG FONT_RENDER_SURFACE_AREA_TYPE_FLAGS_NONE
-        = FONT_RENDER_SURFACE_AREA_TYPE_FLAG(0);
-constexpr FONT_RENDER_SURFACE_AREA_TYPE_FLAG FONT_RENDER_SURFACE_AREA_TYPE_FLAGS_GROW_VERTICAL
-        = FONT_RENDER_SURFACE_AREA_TYPE_FLAG((1 << 0));
-constexpr FONT_RENDER_SURFACE_AREA_TYPE_FLAG FONT_RENDER_SURFACE_AREA_TYPE_FLAGS_GROW_HORIZONTAL
-        = FONT_RENDER_SURFACE_AREA_TYPE_FLAG((1 << 1));
-
-constexpr FONT_RENDER_SURFACE_AREA_TYPE_FLAG FONT_RENDER_SURFACE_AREA_TYPE_FLAGS_STATIC
-        = FONT_RENDER_SURFACE_AREA_TYPE_FLAG(0);
-constexpr FONT_RENDER_SURFACE_AREA_TYPE_FLAG FONT_RENDER_SURFACE_AREA_TYPE_FLAGS_FLUID
-        = FONT_RENDER_SURFACE_AREA_TYPE_FLAG((1 << 0) | (1 << 1));
+const FONT_RENDER_SURFACE_AREA_TYPE_FLAG FONT_RENDER_SURFACE_AREA_TYPE_FLAGS_NONE
+    = FONT_RENDER_SURFACE_AREA_TYPE_FLAG(0u);
+const FONT_RENDER_SURFACE_AREA_TYPE_FLAG FONT_RENDER_SURFACE_AREA_TYPE_FLAGS_CENTER_VERTICAL
+    = FONT_RENDER_SURFACE_AREA_TYPE_FLAG((1u << 0));
+const FONT_RENDER_SURFACE_AREA_TYPE_FLAG FONT_RENDER_SURFACE_AREA_TYPE_FLAGS_CENTER_HORIZONTAL
+    = FONT_RENDER_SURFACE_AREA_TYPE_FLAG((1u << 1));
+const FONT_RENDER_SURFACE_AREA_TYPE_FLAG FONT_RENDER_SURFACE_AREA_TYPE_FLAGS_CENTER_BOTH
+    = FONT_RENDER_SURFACE_AREA_TYPE_FLAG((1u << 0) | (1u << 1));
 
 struct FontRenderHandle {
 	FontTypeIndex index_ft;
@@ -65,7 +62,7 @@ struct FontRenderSettings {
 	float char_spacing_scale = 1.f;
 	glm::ivec2 surface_area_size;
 	glm::ivec2 surface_area_pos;
-	FONT_RENDER_SURFACE_AREA_TYPE_FLAG surface_area_type_flags; // TODO
+	FONT_RENDER_SURFACE_AREA_TYPE_FLAG surface_area_type_flags;
 };
 struct FontRender : public Entity_Base {
 	uint32_t *glyph_indices = nullptr;
diff --git a/tests/pke-test-serialization.cpp b/tests/pke-test-serialization.cpp
index de483f7..0d97174 100644
--- a/tests/pke-test-serialization.cpp
+++ b/tests/pke-test-serialization.cpp
@@ -411,7 +411,7 @@ FontRenderUUID:01010101-0101-0101-0101-010101010101
 UIBox:00000000!00000003
 ChildId:00000000!00000002
 UUID:02020202-0202-0202-0202-020202020202
-Flags:0x84
+Flags:0x3
 PosTopLeft:0.100000;0.100000
 MaxSize:0.800000;0.800000
 Type:0x32
@@ -434,7 +434,7 @@ int pke_test_serialization_003() {
 		frs.line_height_scale = 1.0;
 		frs.surface_area_size = glm::ivec2(250, 250);
 		frs.surface_area_pos = glm::ivec2(0, 0);
-		frs.surface_area_type_flags = FONT_RENDER_SURFACE_AREA_TYPE_FLAGS_FLUID;
+		frs.surface_area_type_flags = FONT_RENDER_SURFACE_AREA_TYPE_FLAGS_CENTER_BOTH;
 		FontRenderHandle fr_handle = FontType_AddStringRender(FontType_GetFonts(idx_unused)[0].index_ft, std::move(cstring_to_pk_cstr("asdf")), &frs, nullptr, uuid_n[1]);
 
 		pke_ui_box *ui_box = pke_ui_box_new_root(PKE_UI_BOX_TYPE_TEXT, uuid_n[2]);
@@ -541,7 +541,7 @@ int pke_test_deserialization_103() {
 		PKE_TEST_ASSERT(fr->settings.char_spacing_scale == 1.f, err_index);
 		PKE_TEST_ASSERT(fr->settings.surface_area_size == glm::ivec2(250,250), err_index);
 		PKE_TEST_ASSERT(fr->settings.surface_area_pos == glm::ivec2(0,0), err_index);
-		PKE_TEST_ASSERT(fr->settings.surface_area_type_flags == FONT_RENDER_SURFACE_AREA_TYPE_FLAGS_FLUID, err_index);
+		PKE_TEST_ASSERT(fr->settings.surface_area_type_flags == FONT_RENDER_SURFACE_AREA_TYPE_FLAGS_CENTER_BOTH, err_index);
 		// auto equal_4 = glm::epsilonEqual(fr->settings.color_foreground, glm::vec4(0.4, 0.9, 0.5, 0.8), epsilon_4);
 		// PKE_TEST_ASSERT(equal_4 == bool_4, err_index);
 		PKE_TEST_ASSERT(fr->settings.color_foreground == glm::vec4(0.4, 0.9, 0.5, 0.8), err_index);