Don't skip whitespace on single-line text (defold#5916)

* Don't skip whitespace on single-line text

* Fix failing tests

Author: britzl

Diff for: engine/render/src/render/font_renderer.cpp

@@ -679,7 +679,11 @@ namespace dmRender
 
         LayoutMetrics lm(font_map, tracking);
         float layout_width;
-        int line_count = Layout(text, width, lines, max_lines, &layout_width, lm);
+        // Whitespace characters should be ignored when rendering multiline text.
+        // For single line text we still want to include whitespaces when the
+        // text layout is calculated (https://github.com/defold/defold/issues/5911)
+        bool skip_whitespace = te.m_LineBreak;
+        int line_count = Layout(text, width, lines, max_lines, &layout_width, lm, skip_whitespace);
         float x_offset = OffsetX(te.m_Align, te.m_Width);
         float y_offset = OffsetY(te.m_VAlign, te.m_Height, font_map->m_MaxAscent, font_map->m_MaxDescent, te.m_Leading, line_count);
 
@@ -1158,7 +1162,11 @@ namespace dmRender
 
         LayoutMetrics lm(font_map, tracking * line_height);
         float layout_width;
-        uint32_t num_lines = Layout(text, width, lines, max_lines, &layout_width, lm);
+        // Whitespace characters should be ignored for multiline text.
+        // For single line text we still want to include whitespaces in text
+        // metrics calculations (https://github.com/defold/defold/issues/5911)
+        bool skip_whitepace = line_break;
+        uint32_t num_lines = Layout(text, width, lines, max_lines, &layout_width, lm, skip_whitepace);
         metrics->m_Width = layout_width;
         metrics->m_Height = num_lines * (line_height * leading) - line_height * (leading - 1.0f);
     }

Diff for: engine/render/src/render/font_renderer_private.h

@@ -1,10 +1,10 @@
 // Copyright 2020 The Defold Foundation
 // Licensed under the Defold License version 1.0 (the "License"); you may not use
 // this file except in compliance with the License.
-// 
+//
 // You may obtain a copy of the License, together with FAQs at
 // https://www.defold.com/license
-// 
+//
 // Unless required by applicable law or agreed to in writing, software distributed
 // under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
 // CONDITIONS OF ANY KIND, either express or implied. See the License for the
@@ -64,7 +64,8 @@ namespace dmRender
                float width,
                TextLine* lines, uint16_t lines_count,
                float* text_width,
-               Metric metrics)
+               Metric metrics,
+               bool skip_whitespace)
     {
         const char* cursor = str;
 
@@ -90,7 +91,7 @@ namespace dmRender
                         last_n = n-trim;
                         last_w = w;
                         last_cursor = cursor;
-                        if (c != '\n')
+                        if (c != '\n' && skip_whitespace)
                             c = SkipWS(&cursor, &n);
                     }
                     else if (last_n != 0)

Diff for: engine/render/src/test/test_render.cpp

@@ -474,85 +474,86 @@ static float Metric(const char* text, int n)
 TEST(dmFontRenderer, Layout)
 {
     const uint32_t lines_count = 256;
+    const bool skip_whitespace = true;
     dmRender::TextLine lines[lines_count];
     int total_lines;
     const float char_width = 4;
     float w;
-    total_lines = dmRender::Layout("", 100, lines, lines_count, &w, Metric);
+    total_lines = dmRender::Layout("", 100, lines, lines_count, &w, Metric, skip_whitespace);
     ASSERT_EQ(0, total_lines);
     ASSERT_EQ(0, w);
 
-    total_lines = dmRender::Layout("x", 100, lines, lines_count, &w, Metric);
+    total_lines = dmRender::Layout("x", 100, lines, lines_count, &w, Metric, skip_whitespace);
     ASSERT_EQ(1, total_lines);
     ASSERT_LINE(0, 1, lines, 0);
     ASSERT_EQ(char_width * 1, w);
 
-    total_lines = dmRender::Layout("x\x00 123", 100, lines, lines_count, &w, Metric);
+    total_lines = dmRender::Layout("x\x00 123", 100, lines, lines_count, &w, Metric, skip_whitespace);
     ASSERT_EQ(1, total_lines);
     ASSERT_LINE(0, 1, lines, 0);
     ASSERT_EQ(char_width * 1, w);
 
-    total_lines = dmRender::Layout("x", 0, lines, lines_count, &w, Metric);
+    total_lines = dmRender::Layout("x", 0, lines, lines_count, &w, Metric, skip_whitespace);
     ASSERT_EQ(1, total_lines);
     ASSERT_LINE(0, 1, lines, 0);
     ASSERT_EQ(char_width * 1, w);
 
-    total_lines = dmRender::Layout("foo", 3 * char_width, lines, lines_count, &w, Metric);
+    total_lines = dmRender::Layout("foo", 3 * char_width, lines, lines_count, &w, Metric, skip_whitespace);
     ASSERT_EQ(1, total_lines);
     ASSERT_LINE(0, 3, lines, 0);
     ASSERT_EQ(char_width * 3, w);
 
-    total_lines = dmRender::Layout("foo", 3 * char_width - 1, lines, lines_count, &w, Metric);
+    total_lines = dmRender::Layout("foo", 3 * char_width - 1, lines, lines_count, &w, Metric, skip_whitespace);
     ASSERT_EQ(1, total_lines);
     ASSERT_LINE(0, 3, lines, 0);
     ASSERT_EQ(char_width * 3, w);
 
-    total_lines = dmRender::Layout("foo bar", 3 * char_width, lines, lines_count, &w, Metric);
+    total_lines = dmRender::Layout("foo bar", 3 * char_width, lines, lines_count, &w, Metric, skip_whitespace);
     ASSERT_EQ(2, total_lines);
     ASSERT_LINE(0, 3, lines, 0);
     ASSERT_LINE(4, 3, lines, 1);
     ASSERT_EQ(char_width * 3, w);
 
-    total_lines = dmRender::Layout("foo bar", 1000, lines, lines_count, &w, Metric);
+    total_lines = dmRender::Layout("foo bar", 1000, lines, lines_count, &w, Metric, skip_whitespace);
     ASSERT_EQ(1, total_lines);
     ASSERT_LINE(0, 7, lines, 0);
     ASSERT_EQ(char_width * 7, w);
 
-    total_lines = dmRender::Layout("foo  bar", 1000, lines, lines_count, &w, Metric);
+    total_lines = dmRender::Layout("foo  bar", 1000, lines, lines_count, &w, Metric, skip_whitespace);
     ASSERT_EQ(1, total_lines);
     ASSERT_LINE(0, 8, lines, 0);
     ASSERT_EQ(char_width * 8, w);
 
-    total_lines = dmRender::Layout("foo\n\nbar", 3 * char_width, lines, lines_count, &w, Metric);
+    total_lines = dmRender::Layout("foo\n\nbar", 3 * char_width, lines, lines_count, &w, Metric, skip_whitespace);
     ASSERT_EQ(3, total_lines);
     ASSERT_LINE(0, 3, lines, 0);
     ASSERT_LINE(4, 0, lines, 1);
     ASSERT_LINE(5, 3, lines, 2);
     ASSERT_EQ(char_width * 3, w);
 
     // 0x200B = Unicode "zero width space", UTF8 representation: E2 80 8B
-    total_lines = dmRender::Layout("foo" "\xe2\x80\x8b" "bar", 3 * char_width, lines, lines_count, &w, Metric);
+    total_lines = dmRender::Layout("foo" "\xe2\x80\x8b" "bar", 3 * char_width, lines, lines_count, &w, Metric, skip_whitespace);
     ASSERT_EQ(2, total_lines);
     ASSERT_LINE(0, 3, lines, 0);
     ASSERT_LINE(6, 3, lines, 1);
     ASSERT_EQ(char_width * 3, w);
 
     // Note that second line would include a "zero width space" as first
     // character since we don't trim whitespace currently.
-    total_lines = dmRender::Layout("foo" "\xe2\x80\x8b\xe2\x80\x8b" "bar", 3 * char_width, lines, lines_count, &w, Metric);
+    total_lines = dmRender::Layout("foo" "\xe2\x80\x8b\xe2\x80\x8b" "bar", 3 * char_width, lines, lines_count, &w, Metric, skip_whitespace);
     ASSERT_EQ(2, total_lines);
     ASSERT_LINE(0, 3, lines, 0);
     ASSERT_LINE(6, 4, lines, 1);
     ASSERT_EQ(char_width * 4, w);
 
     // åäö
-    total_lines = dmRender::Layout("\xc3\xa5\xc3\xa4\xc3\xb6", 3 * char_width, lines, lines_count, &w, Metric);
+    total_lines = dmRender::Layout("\xc3\xa5\xc3\xa4\xc3\xb6", 3 * char_width, lines, lines_count, &w, Metric, skip_whitespace);
     ASSERT_EQ(1, total_lines);
     ASSERT_EQ(char_width * 3, lines[0].m_Width);
     ASSERT_LINE(0, 3, lines, 0);
     ASSERT_EQ(char_width * 3, w);
 
-    total_lines = dmRender::Layout("Welcome to the Kingdom of Games...", 0, lines, lines_count, &w, Metric);
+    total_lines = dmRender::Layout("Welcome to the Kingdom of Games...", 0, lines, lines_count, &w, Metric, skip_whitespace);
     ASSERT_EQ(6, total_lines);
     ASSERT_LINE(0, 7, lines, 0);
     ASSERT_LINE(8, 2, lines, 1);
@@ -621,6 +622,16 @@ TEST_F(dmRenderTest, GetTextMetrics)
     ASSERT_EQ(ExpectedHeight(lineheight, numlines, leading), metrics.m_Height);
 }
 
+TEST_F(dmRenderTest, GetTextMetricsSkipWhitespace)
+{
+    dmRender::TextMetrics metricsSingleLine;
+    dmRender::TextMetrics metricsMultiLine;
+
+    dmRender::GetTextMetrics(m_SystemFontMap, "Hello      ", 0, false, 1.0f, 0.0f, &metricsSingleLine);
+    dmRender::GetTextMetrics(m_SystemFontMap, "Hello      ", 0, true, 1.0f, 0.0f, &metricsMultiLine);
+    ASSERT_NE(metricsMultiLine.m_Width, metricsSingleLine.m_Width);
+}
+
 TEST_F(dmRenderTest, TextAlignment)
 {
     dmRender::TextMetrics metrics;