DrawingTextOnPath in place

Author: arielm

sketches/DrawingTextOnPath/CMakeLists.txt

@@ -0,0 +1,25 @@
+cmake_minimum_required (VERSION 3.2.2)
+
+project(DrawingTextOnPath)
+
+set(INCLUDE_DIRS
+  $ENV{CODE_PATH}
+)
+
+set(SRC_FILES
+  "src/Sketch.cpp"
+  "$ENV{CODE_PATH}/common/xf/Font.cpp"
+  "$ENV{CODE_PATH}/common/xf/FontManager.cpp"
+  "$ENV{CODE_PATH}/common/xf/FontSequence.cpp"
+  "$ENV{CODE_PATH}/common/quad/QuadBatch.cpp"
+)
+
+#
+# For Mojave and up
+#
+add_compile_definitions(
+  GL_SILENCE_DEPRECATION
+)
+
+include("$ENV{CROSS_PATH}/core/cmake/sketch.cmake")
+include("$ENV{CROSS_PATH}/core/cmake/test.cmake")

sketches/DrawingTextOnPath/CTestConfig.cmake

@@ -0,0 +1,15 @@
+
+set(CTEST_PROJECT_NAME DrawingTextOnPath)
+set(CTEST_CONFIGURATION_TYPE Release)
+
+if (PLATFORM MATCHES osx|linux)
+  set(ARGS
+    -DRUN=EXE
+  )
+elseif (PLATFORM MATCHES emscripten)
+  set(ARGS
+    -DRUN=BROWSER
+  )
+endif()
+
+include("$ENV{CROSS_PATH}/core/cmake/platforms.cmake")

sketches/DrawingTextOnPath/res/Georgia_Regular_64.fnt

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+#include "Sketch.h"
+
+#include "chr/path/SplinePath.h"
+
+using namespace std;
+using namespace chr;
+using namespace gl;
+using namespace math;
+using namespace path;
+
+const u16string TEXT = u"Some girls are bigger than others. Some girls mothers are bigger than other girls' mothers."; // Lyrics by the Smiths
+
+void Sketch::setup()
+{
+    font = fontManager.getFont(InputSource::resource("Georgia_Regular_64.fnt"), XFont::Properties2d());
+    font->setShader(textureAlphaShader);
+    font->setSize(20);
+    font->setColor(0, 0, 0, 1);
+
+    lineBatch
+        .setPrimitive(GL_LINES)
+        .setShader(colorShader)
+        .setShaderColor(0, 0, 0, 0.25f);
+
+    // ---
+
+    MatrixAffine matrix;
+    matrix.scale(3);
+
+    SplinePath<glm::vec2> peanut;
+    peanut
+        .setType(SplinePath<glm::vec2>::TYPE_BSPLINE)
+        .setSamplingTolerance(16)
+        .add(-100, -100)
+        .add(   0,  -25)
+        .add( 100, -100)
+        .add( 200,    0)
+        .add( 100,  100)
+        .add(   0,   25)
+        .add(-100,  100)
+        .add(-200,    0)
+        .close()
+        .transformPoints(matrix);
+
+    path
+        .setMode(FollowablePath2D::MODE_LOOP)
+        .begin()
+        .add(peanut.getPolyline())
+        .end();
+
+    drawPolyline(path.getPoints());
+
+    // ---
+
+    glDisable(GL_DEPTH_TEST);
+    glDepthMask(GL_FALSE);
+
+    glEnable(GL_BLEND);
+    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+}
+
+void Sketch::resize()
+{}
+
+void Sketch::draw()
+{
+    glClearColor(1, 1, 1, 1);
+    glClear(GL_COLOR_BUFFER_BIT);
+
+    // ---
+
+    auto projectionMatrix = glm::ortho(0.0f, windowInfo.width, 0.0f, windowInfo.height);
+
+    Matrix modelViewMatrix;
+    modelViewMatrix
+        .translate(windowInfo.center())
+        .scale(1, -1);
+
+    gl::State()
+        .setShaderMatrix(modelViewMatrix * projectionMatrix)
+        .apply();
+
+    // ---
+
+    lineBatch.flush();
+
+    font->beginSequence(sequence);
+    drawTextOnPath(*font, TEXT, path, -clock()->getTime() * 75.0f, XFont::ALIGN_MIDDLE);
+    font->endSequence();
+    font->replaySequence(sequence);
+}
+
+void Sketch::drawPolyline(const vector<FollowablePath2D::Point> &points)
+{
+    auto size = points.size();
+    if (size > 1)
+    {
+        for (auto i = 0; i < size - 1; i++)
+        {
+            lineBatch.addVertices(points[i].position, points[i + 1].position);
+        }
+    }
+}
+
+void Sketch::drawTextOnPath(XFont &font, const u16string &text, const FollowablePath2D &path, float offset, XFont::Alignment alignY)
+{
+    float offsetY = font.getOffsetY(alignY);
+    Matrix matrix;
+
+    for (auto c : text)
+    {
+        auto glyphIndex = font.getGlyphIndex(c);
+        float halfWidth = font.getGlyphAdvance(glyphIndex) / 2;
+        offset += halfWidth;
+
+        if (glyphIndex >= 0)
+        {
+            path
+                .offsetToValue(offset, halfWidth * 2)
+                .applyToMatrix(matrix);
+
+            font.addGlyph(matrix, glyphIndex, -halfWidth, offsetY);
+        }
+
+        offset += halfWidth;
+    }
+}

sketches/DrawingTextOnPath/src/Sketch.cpp

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+#pragma once
+
+#include "chr/cross/Context.h"
+#include "chr/gl/Batch.h"
+#include "chr/gl/shaders/ColorShader.h"
+#include "chr/gl/shaders/TextureAlphaShader.h"
+#include "chr/path/FollowablePath2D.h"
+
+#include "common/xf/FontManager.h"
+
+class Sketch : public chr::CrossSketch
+{
+public:
+    void setup() final;
+    void resize() final;
+    void draw() final;
+
+protected:
+    chr::gl::VertexBatch<chr::gl::XYZ> lineBatch;
+    chr::gl::shaders::ColorShader colorShader;
+
+    chr::xf::FontManager fontManager;
+    std::shared_ptr<chr::XFont> font;
+    chr::xf::FontSequence sequence;
+    chr::gl::shaders::TextureAlphaShader textureAlphaShader;
+
+    chr::path::FollowablePath2D path;
+
+    void drawPolyline(const std::vector<chr::path::FollowablePath2D::Point> &points);
+    static void drawTextOnPath(chr::XFont &font, const std::u16string &text, const chr::path::FollowablePath2D &path, float offset, chr::XFont::Alignment alignY);
+};

sketches/DrawingTextOnPath/src/Sketch.h

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+
+#include "Sketch.h"
+
+namespace chr
+{
+  CrossSketch* createSketch()
+  {
+    return new Sketch();
+  }
+}
+
+#if defined(CHR_PLATFORM_DESKTOP)
+
+  int main(int argc, char** argv)
+  {
+    chr::CrossSketch::run(1200, 900, 4);
+    return 0;
+  }
+
+#elif defined(CHR_PLATFORM_EMSCRIPTEN)
+
+  int main(int argc, char** argv)
+  {
+    chr::CrossSketch::run(4);
+    return 0;
+  }
+
+#endif