Added header for OS drawing and a double buffer.

targets/_any/include/os/draw.hpp

@@ -0,0 +1,69 @@
+
+#pragma once
+
+#if !defined(BAD_APPLE_OS_DRAW_HPP_INCLUDED)
+#define BAD_APPLE_OS_DRAW_HPP_INCLUDED
+
+#include <stdint.h>
+#include <vector>
+
+namespace draw
+{
+const unsigned SIZE_FULL = static_cast<unsigned>(-1);
+
+struct Pixel
+{
+    uint8_t blue = 0;
+    uint8_t green = 0;
+    uint8_t red = 0;
+    uint8_t reserved_ = 0;
+};
+
+class Framebuffer
+{
+protected:
+    Pixel* mBase = nullptr;
+    unsigned mWidth = 0;
+    unsigned mHeight = 0;
+    unsigned mPitch = 0;
+public:
+    Framebuffer() = default;
+    Framebuffer(const Framebuffer&) = default;
+    Framebuffer(Pixel* base, unsigned width, unsigned height, unsigned pitch) noexcept
+        : mBase(base), mWidth(width), mHeight(height), mPitch(pitch) {}
+
+    [[nodiscard]] Pixel* getBase() const noexcept { return mBase; }
+    [[nodiscard]] unsigned getWidth() const noexcept { return mWidth; }
+    [[nodiscard]] unsigned getHeight() const noexcept { return mHeight; }
+    [[nodiscard]] unsigned getPitch() const noexcept { return mPitch; }
+    [[nodiscard]] unsigned getBufferSize() const noexcept { return mPitch * mHeight * sizeof(Pixel); }
+
+    void setPixel(unsigned posX, unsigned posY, Pixel pixel) noexcept;
+};
+
+class OwningFramebuffer : public Framebuffer
+{
+private:
+    std::vector<Pixel> mPixels;
+public:
+    OwningFramebuffer() = default;
+    OwningFramebuffer(const OwningFramebuffer&) noexcept = default;
+    OwningFramebuffer(OwningFramebuffer&&) noexcept = default;
+    OwningFramebuffer(unsigned width, unsigned height, unsigned pitch) noexcept;
+
+    OwningFramebuffer& operator=(const OwningFramebuffer&) noexcept = default;
+    OwningFramebuffer& operator=(OwningFramebuffer&&) noexcept = default;
+
+    static OwningFramebuffer makeFrom(const Framebuffer& other) noexcept
+    {
+        return OwningFramebuffer(other.getWidth(), other.getHeight(), other.getPitch());
+    }
+};
+
+void initializeDefaultFramebuffer(const Framebuffer& framebuffer) noexcept;
+void setPixelDirect(unsigned posX, unsigned posY, Pixel pixel) noexcept;
+void setPixel(unsigned posX, unsigned posY, Pixel pixel) noexcept;
+void flushPixels() noexcept;
+}
+
+#endif // !defined(BAD_APPLE_OS_FRAMEBUFFER_HPP_INCLUDED)