libui: Add a GUI and graphics library

CMakeLists.txt

@@ -45,6 +45,7 @@ endif()
 
 add_subdirectory(libluna)
 add_subdirectory(libos)
+add_subdirectory(libui)
 add_subdirectory(libc)
 add_subdirectory(kernel)
 add_subdirectory(apps)

libui/CMakeLists.txt

@@ -0,0 +1,15 @@
+# The UI and graphics library for Luna.
+
+file(GLOB HEADERS include/ui/*.h)
+
+set(SOURCES
+    ${HEADERS}
+    src/Canvas.cpp
+    src/Color.cpp
+    src/Rect.cpp
+)
+
+add_library(ui ${SOURCES})
+target_compile_options(ui PRIVATE ${COMMON_FLAGS})
+target_include_directories(ui PUBLIC ${CMAKE_CURRENT_LIST_DIR}/include/)
+target_include_directories(ui PUBLIC ${LUNA_BASE}/usr/include)

libui/include/ui/Canvas.h

@@ -0,0 +1,30 @@
+#pragma once
+#include <luna/Result.h>
+#include <luna/Types.h>
+#include <ui/Color.h>
+#include <ui/Point.h>
+#include <ui/Rect.h>
+
+namespace ui
+{
+    /**
+     * @brief A drawable surface.
+     */
+    struct Canvas
+    {
+        int width;
+        int height;
+        int stride;
+        u8* ptr;
+
+        static Canvas create(u8* ptr, int width, int height);
+        Result<Canvas> subcanvas(Point begin, int width, int height, bool clamp);
+
+        Rect rect()
+        {
+            return Rect { .begin = { 0, 0 }, .width = width, .height = height };
+        }
+
+        void fill(Color color);
+    };
+};

libui/include/ui/Color.h

@@ -0,0 +1,34 @@
+#pragma once
+#include <luna/Types.h>
+
+namespace ui
+{
+    /**
+     * @brief A 32-bit RGBA color.
+     */
+    struct Color
+    {
+        union {
+            u32 raw;
+            u8 colors[4];
+        };
+
+        static constexpr Color from_u32(u32 raw)
+        {
+            return Color { .raw = raw };
+        }
+
+        static constexpr Color from_rgba(u8 red, u8 green, u8 blue, u8 alpha)
+        {
+            return Color { .colors = { blue, green, red, alpha } };
+        }
+
+        static constexpr Color from_rgb(u8 red, u8 green, u8 blue)
+        {
+            return from_rgba(red, green, blue, 0xff);
+        }
+    };
+
+    static constexpr Color WHITE = Color::from_rgb(0xff, 0xff, 0xff);
+    static constexpr Color BLACK = Color::from_rgb(0x00, 0x00, 0x00);
+};

libui/include/ui/Point.h

@@ -0,0 +1,13 @@
+#pragma once
+
+namespace ui
+{
+    /**
+     * @brief A point in 2D space.
+     */
+    struct Point
+    {
+        int x { 0 };
+        int y { 0 };
+    };
+}

libui/include/ui/Rect.h

@@ -0,0 +1,18 @@
+#pragma once
+#include <ui/Point.h>
+
+namespace ui
+{
+    /**
+     * @brief A simple rectangle.
+     */
+    struct Rect
+    {
+        Point begin;
+        int width;
+        int height;
+
+        bool contains(Point point);
+        Point normalize(Point point);
+    };
+}

libui/src/Canvas.cpp

@@ -0,0 +1,43 @@
+#include <string.h>
+#include <ui/Canvas.h>
+
+namespace ui
+{
+    Canvas Canvas::create(u8* ptr, int width, int height)
+    {
+        return Canvas { .width = width, .height = height, .stride = width, .ptr = ptr };
+    }
+
+    Result<Canvas> Canvas::subcanvas(Point begin, int w, int h, bool clamp)
+    {
+        if (!clamp)
+        {
+            if (begin.x + w > width) return err(ERANGE);
+            if (begin.y + h > height) return err(ERANGE);
+        }
+        else
+        {
+            if (begin.x + w > width) w = width - begin.x;
+            if (begin.y + h > height) h = height - begin.y;
+        }
+
+        u8* p = ptr + begin.x * sizeof(Color) + (begin.y * sizeof(Color) * stride);
+
+        return Canvas { .width = w, .height = h, .stride = stride, .ptr = p };
+    }
+
+    void Canvas::fill(Color color)
+    {
+        u8* p = ptr;
+        for (int i = 0; i < height; i++)
+        {
+            u32* colorp = (u32*)p;
+            for (int j = 0; j < width; j++)
+            {
+                *colorp = color.raw;
+                colorp++;
+            }
+            p += stride * sizeof(Color);
+        }
+    }
+}

libui/src/Rect.cpp

@@ -0,0 +1,18 @@
+#include <ui/Rect.h>
+
+namespace ui
+{
+    bool Rect::contains(Point point)
+    {
+        return point.x >= begin.x && point.y >= begin.y && point.x <= begin.x + width && point.y <= begin.y + height;
+    }
+
+    Point Rect::normalize(Point point)
+    {
+        if (point.x < begin.x) point.x = begin.x;
+        if (point.y < begin.y) point.y = begin.y;
+        if (point.x > begin.x + width) point.x = begin.x + width;
+        if (point.y > begin.y + height) point.y = begin.y + height;
+        return point;
+    }
+};

tools/install-headers.sh

@@ -8,10 +8,12 @@ cd $LUNA_ROOT
 mkdir -p $LUNA_BASE
 mkdir -p $LUNA_BASE/usr/include
 mkdir -p $LUNA_BASE/usr/include/luna
+mkdir -p $LUNA_BASE/usr/include/ui
 mkdir -p $LUNA_BASE/usr/include/os
 mkdir -p $LUNA_BASE/usr/include/moon
 
 cp --preserve=timestamps -RT libc/include/ $LUNA_BASE/usr/include
 cp --preserve=timestamps -RT libluna/include/luna/ $LUNA_BASE/usr/include/luna
+cp --preserve=timestamps -RT libui/include/ui/ $LUNA_BASE/usr/include/ui
 cp --preserve=timestamps -RT libos/include/os/ $LUNA_BASE/usr/include/os
 cp --preserve=timestamps -RT kernel/src/api/ $LUNA_BASE/usr/include/moon

tools/sources.sh

@@ -4,7 +4,7 @@ source $(dirname $0)/env.sh
 
 cd $LUNA_ROOT
 
-FOLDERS=(kernel libc libos libluna apps shell tests)
+FOLDERS=(kernel libc libos libui libluna apps shell tests)
 
 SOURCES=($(find ${FOLDERS[@]} -type f -name "*.cpp"))
 SOURCES+=($(find ${FOLDERS[@]} -type f -name "*.h"))