done phase 1 code base

cmake/skia.cmake

@@ -33,7 +33,7 @@ endif()
 add_library(skia::skia STATIC IMPORTED GLOBAL)
 set_target_properties(skia::skia PROPERTIES
     IMPORTED_LOCATION "${SKIA_LIBRARY}"
-    INTERFACE_INCLUDE_DIRECTORIES "${SKIA_INCLUDE_DIR}/include")
+    INTERFACE_INCLUDE_DIRECTORIES "${SKIA_INCLUDE_DIR}")
 
 if(UNIX AND NOT APPLE)
     set_property(TARGET skia::skia APPEND PROPERTY

engine/CMakeLists.txt

@@ -13,6 +13,7 @@ add_library(pdfengine STATIC
     src/core/engine_info.cpp
     src/core/graphics_state.cpp
     src/core/display_list.cpp
+    src/core/skia_renderer.cpp
     src/parser/pdfium_loader.cpp
     src/parser/pdfium_document.cpp
     src/fonts/font_face.cpp
@@ -44,7 +45,7 @@ endif()
 
 if(PDFENGINE_WITH_SKIA)
     target_link_libraries(pdfengine PRIVATE skia::skia)
-    target_compile_definitions(pdfengine PRIVATE PDFENGINE_WITH_SKIA)
+    target_compile_definitions(pdfengine PUBLIC PDFENGINE_WITH_SKIA)
 endif()
 
 pdfengine_set_warnings(pdfengine)

engine/include/pdfengine/skia_renderer.hpp

@@ -0,0 +1,31 @@
+#pragma once
+
+#include <pdfengine/display_list.hpp>
+#include <pdfengine/graphics_state.hpp>
+
+class SkCanvas;
+
+namespace pdfengine {
+
+// A visitor that replays a DisplayList onto a Skia canvas.
+class SkiaRenderer : public CommandVisitor {
+public:
+    // Takes a pointer to an external SkCanvas. 
+    // The caller is responsible for the canvas's lifecycle.
+    explicit SkiaRenderer(SkCanvas* canvas);
+
+    void visit(const SaveStateCommand& cmd) override;
+    void visit(const RestoreStateCommand& cmd) override;
+    void visit(const SetTransformCommand& cmd) override;
+    void visit(const FillRectCommand& cmd) override;
+    void visit(const DrawTextCommand& cmd) override;
+
+    // Renders the entire display list to the canvas
+    void render(const DisplayList& displayList);
+
+private:
+    SkCanvas* m_canvas;
+    GraphicsStateStack m_stateStack;
+};
+
+} // namespace pdfengine

engine/src/core/skia_renderer.cpp

@@ -0,0 +1,96 @@
+#include "pdfengine/skia_renderer.hpp"
+
+#ifdef PDFENGINE_WITH_SKIA
+#include <include/core/SkCanvas.h>
+#include <include/core/SkPaint.h>
+#include <include/core/SkMatrix.h>
+#include <include/core/SkFont.h>
+#include <include/core/SkTypeface.h>
+#endif
+
+namespace pdfengine {
+
+SkiaRenderer::SkiaRenderer(SkCanvas* canvas) : m_canvas(canvas) {}
+
+void SkiaRenderer::render(const DisplayList& displayList) {
+    if (!m_canvas) return;
+    
+    // Iterate and accept commands
+    displayList.replay(*this);
+}
+
+void SkiaRenderer::visit(const SaveStateCommand& cmd) {
+    (void)cmd;
+#ifdef PDFENGINE_WITH_SKIA
+    if (m_canvas) m_canvas->save();
+#endif
+    m_stateStack.push();
+}
+
+void SkiaRenderer::visit(const RestoreStateCommand& cmd) {
+    (void)cmd;
+#ifdef PDFENGINE_WITH_SKIA
+    if (m_canvas) m_canvas->restore();
+#endif
+    m_stateStack.pop();
+}
+
+void SkiaRenderer::visit(const SetTransformCommand& cmd) {
+#ifdef PDFENGINE_WITH_SKIA
+    if (m_canvas) {
+        SkMatrix skMatrix;
+        // Map 2D affine matrix to Skia's 3x3 matrix
+        // [ a c e ] (Skia) vs [ a b 0 ]
+        // [ b d f ]         [ c d 0 ]
+        // [ 0 0 1 ]         [ e f 1 ]
+        skMatrix.setAll(
+            cmd.matrix.a, cmd.matrix.c, cmd.matrix.e,
+            cmd.matrix.b, cmd.matrix.d, cmd.matrix.f,
+            0.0f, 0.0f, 1.0f
+        );
+        m_canvas->concat(skMatrix);
+    }
+#endif
+    // Also update internal state if we need it later
+    m_stateStack.current().ctm = m_stateStack.current().ctm.multiply(cmd.matrix);
+}
+
+void SkiaRenderer::visit(const FillRectCommand& cmd) {
+#ifdef PDFENGINE_WITH_SKIA
+    if (!m_canvas) return;
+    
+    SkPaint paint;
+    paint.setAntiAlias(true);
+    
+    const auto& color = m_stateStack.current().fillColor;
+    paint.setColor(SkColorSetARGB(255, 
+        static_cast<uint8_t>(color.r * 255), 
+        static_cast<uint8_t>(color.g * 255), 
+        static_cast<uint8_t>(color.b * 255)));
+
+    SkRect rect = SkRect::MakeXYWH(cmd.x, cmd.y, cmd.width, cmd.height);
+    m_canvas->drawRect(rect, paint);
+#endif
+}
+
+void SkiaRenderer::visit(const DrawTextCommand& cmd) {
+#ifdef PDFENGINE_WITH_SKIA
+    if (!m_canvas) return;
+
+    SkPaint paint;
+    paint.setAntiAlias(true);
+    
+    const auto& color = m_stateStack.current().fillColor;
+    paint.setColor(SkColorSetARGB(255, 
+        static_cast<uint8_t>(color.r * 255), 
+        static_cast<uint8_t>(color.g * 255), 
+        static_cast<uint8_t>(color.b * 255)));
+
+    // For phase 0/1 testing, we use a default typeface
+    SkFont font(nullptr, 12.0f);
+
+    m_canvas->drawString(cmd.text.c_str(), cmd.x, cmd.y, font, paint);
+#endif
+}
+
+} // namespace pdfengine

engine/tests/CMakeLists.txt

@@ -6,6 +6,7 @@ add_executable(pdfengine_smoke
     graphics_state_test.cpp
     display_list_test.cpp
     document_test.cpp
+    skia_renderer_test.cpp
 )
 
 target_link_libraries(pdfengine_smoke
@@ -15,6 +16,10 @@ target_link_libraries(pdfengine_smoke
         GTest::gtest_main
 )
 
+if(PDFENGINE_WITH_SKIA)
+    target_link_libraries(pdfengine_smoke PRIVATE skia::skia)
+endif()
+
 target_include_directories(pdfengine_smoke
     PRIVATE
         "${CMAKE_CURRENT_SOURCE_DIR}/../src"

engine/tests/skia_renderer_test.cpp

@@ -0,0 +1,42 @@
+#include <gtest/gtest.h>
+#include <pdfengine/display_list.hpp>
+#include <pdfengine/skia_renderer.hpp>
+
+#ifdef PDFENGINE_WITH_SKIA
+#include <include/core/SkBitmap.h>
+#include <include/core/SkCanvas.h>
+#endif
+
+using namespace pdfengine;
+
+TEST(SkiaRendererTest, RenderSimpleDisplayList) {
+#ifdef PDFENGINE_WITH_SKIA
+    SkBitmap bitmap;
+    bitmap.allocN32Pixels(100, 100);
+    SkCanvas canvas(bitmap);
+    canvas.clear(SK_ColorWHITE);
+
+    DisplayList dl;
+    // Push state and set fill color to red
+    dl.saveState();
+    dl.fillRect(10, 10, 50, 50); // Will be filled with red (we need a SetFillColorCommand, but right now GraphicsState doesn't expose it directly via Command yet. It will use default black)
+    dl.restoreState();
+
+    SkiaRenderer renderer(&canvas);
+    renderer.render(dl);
+
+    // Let's verify that a pixel at (20,20) was drawn. Since default color is black (0,0,0), we check that.
+    SkColor c = bitmap.getColor(20, 20);
+    EXPECT_EQ(SkColorGetR(c), 0);
+    EXPECT_EQ(SkColorGetG(c), 0);
+    EXPECT_EQ(SkColorGetB(c), 0);
+
+    // Check outside the rect
+    SkColor bg = bitmap.getColor(5, 5);
+    EXPECT_EQ(SkColorGetR(bg), 255);
+    EXPECT_EQ(SkColorGetG(bg), 255);
+    EXPECT_EQ(SkColorGetB(bg), 255);
+#else
+    GTEST_SKIP() << "PDFENGINE_WITH_SKIA not defined. Skia tests skipped.";
+#endif
+}