From 46eff4429781ecbb25258c419ba2153d6f357692 Mon Sep 17 00:00:00 2001
From: Hartmut Seichter <hartmut@technotecture.com>
Date: Wed, 16 Jan 2019 11:13:12 +0100
Subject: [PATCH] adding important low-level code for image and matrix
 manipulations

---
 src/core/include/pw/core/image.hpp  | 32 +++++++++----
 src/core/include/pw/core/matrix.hpp |  2 -
 src/core/include/pw/core/size.hpp   |  2 +
 src/core/src/image.cpp              | 71 +++++++++++++++++++++++++++++
 4 files changed, 96 insertions(+), 11 deletions(-)

diff --git a/src/core/include/pw/core/image.hpp b/src/core/include/pw/core/image.hpp
index 73ff30d..4c50ea6 100644
--- a/src/core/include/pw/core/image.hpp
+++ b/src/core/include/pw/core/image.hpp
@@ -33,22 +33,36 @@ public:
 
     image() = default;
 
-	enum image_type {
-		RGB8,
-		RGBA8,
-		LUM
-	};
+    enum pixel_layout {
+        RGB8,
+        RGBA8,
+        LUM
+    };
 
-	bool create(const sizei& size,);
+    image(const sizei& s, pixel_layout t, void *ptr = nullptr);
+
+    bool create(const sizei& s, pixel_layout t, void *ptr = nullptr);
+
+    void destroy(bool release_memory = false);
 
 	const uint8_t *data() const { return _data.data(); }
 	uint8_t *data() { return _data.data(); }
 
+    pixel_layout layout() const;
+    void set_layout(const pixel_layout &layout);
+
+    uint64_t change_count() const;
+    void set_change_count(const uint64_t &change_count);
+
+    static uint32_t bytes_per_pixel(pixel_layout t);
+
 protected:
 
-	sizei _size;
-	std::vector<uint8_t> _data;
-    std::string _uri;
+    sizei _size;
+    pixel_layout _layout;
+    uint64_t _change_count;
+
+    std::vector<uint8_t> _data;
 
 };
 
diff --git a/src/core/include/pw/core/matrix.hpp b/src/core/include/pw/core/matrix.hpp
index a2de3b7..2f9a13f 100644
--- a/src/core/include/pw/core/matrix.hpp
+++ b/src/core/include/pw/core/matrix.hpp
@@ -487,8 +487,6 @@ public:
 
 };
 
-//////////////////////////////////////////////////////////////////////////
-
 //
 // Specializations
 //
diff --git a/src/core/include/pw/core/size.hpp b/src/core/include/pw/core/size.hpp
index 6cf4e9e..69a9324 100644
--- a/src/core/include/pw/core/size.hpp
+++ b/src/core/include/pw/core/size.hpp
@@ -36,6 +36,8 @@ struct size_ {
 
 	size_(T_ w,T_ h) : width(w), height(h) {}
 
+    T_ area() const { return std::abs(width * height); }
+
 };
 
 typedef size_<real_t> size;
diff --git a/src/core/src/image.cpp b/src/core/src/image.cpp
index e69de29..11c9e0e 100644
--- a/src/core/src/image.cpp
+++ b/src/core/src/image.cpp
@@ -0,0 +1,71 @@
+#include "pw/core/image.hpp"
+
+#include <limits>
+
+namespace pw {
+
+image::image(const sizei &s, image::pixel_layout t, void *ptr)
+{
+
+}
+
+bool image::create(const sizei &s, image::pixel_layout t, void *ptr)
+{
+    auto n = bytes_per_pixel(t) * s.area();
+
+    if (ptr != nullptr) {
+
+        auto a = reinterpret_cast<uint8_t*>(ptr);
+
+        _data.assign(a,a + n);
+
+    } else {
+
+        _data.resize(n,0);
+    }
+
+    return !_data.empty();
+}
+
+void image::destroy(bool release_memory)
+{
+    _data.clear();
+
+    if (release_memory) _data.shrink_to_fit();
+}
+
+uint32_t image::bytes_per_pixel(image::pixel_layout t)
+{
+    switch (t) {
+    case pw::image::RGB8:
+        return 3;
+    case pw::image::RGBA8:
+        return 4;
+    case pw::image::LUM:
+        return 1;
+    }
+
+    return std::numeric_limits<uint32_t>::max();
+}
+
+image::pixel_layout image::layout() const
+{
+    return _layout;
+}
+
+void image::set_layout(const pixel_layout &layout)
+{
+    _layout = layout;
+}
+
+uint64_t image::change_count() const
+{
+    return _change_count;
+}
+
+void image::set_change_count(const uint64_t &change_count)
+{
+    _change_count = change_count;
+}
+
+}