add ImageData.drawLine

src/graphics/core/ImageData.cpp

@@ -3,6 +3,7 @@
 #include <assert.h>
 #include <stdexcept>
 #include <cstring>
+#include <cmath>
 #include <algorithm>
 
 ImageData::ImageData(ImageFormat format, uint width, uint height) 
@@ -93,6 +94,99 @@ void ImageData::blit(const ImageData* image, int x, int y) {
     throw std::runtime_error("mismatching format");
 }
 
+static bool clip_line(int& x1, int& y1, int& x2, int& y2, int width, int height) {
+    const int left = 0;
+    const int right = width;
+    const int bottom = 0;
+    const int top = height;
+
+    int dx = x2 - x1;
+    int dy = y2 - y1;
+
+    float t0 = 0.0f;
+    float t1 = 1.0f;
+
+    auto clip = [](int p, int q, float& t0, float& t1) {
+        if (p == 0) {
+            return q >= 0;
+        }
+        float t = static_cast<float>(q) / p;
+        if (p < 0) {
+            if (t > t1) return false;
+            if (t > t0) t0 = t;
+        } else {
+            if (t < t0) return false;
+            if (t < t1) t1 = t;
+        }
+        return true;
+    };
+
+    if (!clip(-dx, x1 - left, t0, t1)) return false;
+    if (!clip( dx, right - x1, t0, t1)) return false;
+    if (!clip(-dy, y1 - bottom, t0, t1)) return false;
+    if (!clip( dy, top - y1, t0, t1)) return false;
+
+    if (t1 < 1.0f) {
+        x2 = x1 + static_cast<int>(std::round(t1 * dx));
+        y2 = y1 + static_cast<int>(std::round(t1 * dy));
+    }
+    if (t0 > 0.0f) {
+        x1 = x1 + static_cast<int>(std::round(t0 * dx));
+        y1 = y1 + static_cast<int>(std::round(t0 * dy));
+    }
+    return true;
+}
+
+template<uint channels>
+static void draw_line(ImageData& image, int x1, int y1, int x2, int y2, const glm::ivec4& color) {
+    ubyte* data = image.getData();
+    uint width = image.getWidth();
+    uint height = image.getHeight();
+
+    if ((x1 < 0 || x1 >= width || x2 < 0 || x2 >= width ||
+        y1 < 0 || y1 >= height || y2 < 0 || y2 >= height) &&
+        !clip_line(x1, y1, x2, y2, width, height)) {
+        return;
+    }
+    
+    int dx = std::abs(x2 - x1);
+    int dy = -std::abs(y2 - y1);
+    int sx = x1 < x2 ? 1 : -1;
+    int sy = y1 < y2 ? 1 : -1;
+    int err = dx + dy;
+
+    while (true) {
+        size_t pos = (y1 * width + x1) * channels;
+        for (int i = 0; i < channels; i++) {
+            data[pos + i] = color[i];
+        }
+        if (x1 == x2 && y1 == y2) break;
+        
+        int e2 = 2 * err;
+        if (e2 >= dy) {
+            err += dy;
+            x1 += sx;
+        }
+        if (e2 <= dx) {
+            err += dx;
+            y1 += sy;
+        }
+    }
+}
+
+void ImageData::drawLine(int x1, int y1, int x2, int y2, const glm::ivec4& color) {
+    switch (format) {
+        case ImageFormat::rgb888:
+            draw_line<3>(*this, x1, y1, x2, y2, color);
+            break;
+        case ImageFormat::rgba8888:
+            draw_line<4>(*this, x1, y1, x2, y2, color);
+            break;
+        default:
+            break;
+    }
+}
+
 void ImageData::blitRGB_on_RGBA(const ImageData* image, int x, int y) {
     ubyte* source = image->getData();
     uint srcwidth = image->getWidth();

src/graphics/core/ImageData.hpp

@@ -2,6 +2,7 @@
 
 #include "typedefs.hpp"
 
+#include <glm/vec4.hpp>
 #include <memory>
 
 enum class ImageFormat {
@@ -23,6 +24,7 @@ public:
     void flipX();
     void flipY();
 
+    void drawLine(int x1, int y1, int x2, int y2, const glm::ivec4& color);
     void blitRGB_on_RGBA(const ImageData* image, int x, int y);
     void blitMatchingFormat(const ImageData* image, int x, int y);
     void blit(const ImageData* image, int x, int y);
@@ -44,6 +46,11 @@ public:
     uint getHeight() const {
         return height;
     }
+
+    size_t getDataSize() const {
+        size_t channels = 3 + (format == ImageFormat::rgba8888);
+        return width * height * channels;
+    }
 };
 
 std::unique_ptr<ImageData> add_atlas_margins(ImageData* image, int grid_size);

src/logic/scripting/lua/usertypes/lua_type_canvas.cpp

@@ -80,65 +80,26 @@ static int l_set(State* L) {
 }
 
 static int l_clear(State* L) {
-    RGBA rgba {};
+    auto canvas = touserdata<LuaCanvas>(L, 1);
-    if (gettop(L) > 1) {
+    if (canvas == nullptr) {
-        rgba = get_rgba(L, 2);
+        throw std::runtime_error("used canvas.clear instead of canvas:clear");
     }
-    if (auto canvas = touserdata<LuaCanvas>(L, 1)) {
+    auto& image = canvas->data();
-        auto& image = canvas->data();
+    ubyte* data = image.getData();
-        ubyte* data = image.getData();
+    RGBA rgba {};
-        size_t pixels = image.getWidth() * image.getHeight();
+    if (gettop(L) == 1) {
-        const size_t channels = 4;
+        std::fill(data, data + image.getDataSize(), 0);
-        for (size_t i = 0; i < pixels * channels; i++) {
+        return 0;
-            data[i] = rgba.arr[i % channels];
+    }
-        }
+    rgba = get_rgba(L, 2);
+    size_t pixels = image.getWidth() * image.getHeight();
+    const size_t channels = 4;
+    for (size_t i = 0; i < pixels * channels; i++) {
+        data[i] = rgba.arr[i % channels];
     }
     return 0;
 }
 
-bool clip_line(int& x1, int& y1, int& x2, int& y2, int width, int height) {
-    const int left = 0;
-    const int right = width;
-    const int bottom = 0;
-    const int top = height;
-
-    int dx = x2 - x1;
-    int dy = y2 - y1;
-
-    float t0 = 0.0f;
-    float t1 = 1.0f;
-
-    auto clip = [](int p, int q, float& t0, float& t1) {
-        if (p == 0) {
-            return q >= 0;
-        }
-        float t = static_cast<float>(q) / p;
-        if (p < 0) {
-            if (t > t1) return false;
-            if (t > t0) t0 = t;
-        } else {
-            if (t < t0) return false;
-            if (t < t1) t1 = t;
-        }
-        return true;
-    };
-
-    if (!clip(-dx, x1 - left, t0, t1)) return false;
-    if (!clip( dx, right - x1, t0, t1)) return false;
-    if (!clip(-dy, y1 - bottom, t0, t1)) return false;
-    if (!clip( dy, top - y1, t0, t1)) return false;
-
-    if (t1 < 1.0f) {
-        x2 = x1 + static_cast<int>(std::round(t1 * dx));
-        y2 = y1 + static_cast<int>(std::round(t1 * dy));
-    }
-    if (t0 > 0.0f) {
-        x1 = x1 + static_cast<int>(std::round(t0 * dx));
-        y1 = y1 + static_cast<int>(std::round(t0 * dy));
-    }
-    return true;
-}
-
 static int l_line(State* L) {
     int x1 = tointeger(L, 2);
     int y1 = tointeger(L, 3);
@@ -149,40 +110,9 @@ static int l_line(State* L) {
     RGBA rgba = get_rgba(L, 6);
     if (auto canvas = touserdata<LuaCanvas>(L, 1)) {
         auto& image = canvas->data();
-        ubyte* data = image.getData();
+        image.drawLine(
-        uint width = image.getWidth();
+            x1, y1, x2, y2, glm::ivec4 {rgba.r, rgba.g, rgba.b, rgba.a}
-        uint height = image.getHeight();
+        );
-        const uint channels = 4;
-
-        if ((x1 < 0 || x1 >= width || x2 < 0 || x2 >= width ||
-            y1 < 0 || y1 >= height || y2 < 0 || y2 >= height) &&
-            !clip_line(x1, y1, x2, y2, width, height)) {
-            return 0;
-        }
-        
-        int dx = glm::abs(x2 - x1);
-        int dy = -glm::abs(y2 - y1);
-        int sx = x1 < x2 ? 1 : -1;
-        int sy = y1 < y2 ? 1 : -1;
-        int err = dx + dy;
-    
-        while (true) {
-            size_t pos = (y1 * width + x1) * channels;
-            for (int i = 0; i < channels; i++) {
-                data[pos + i] = rgba.arr[i];
-            }
-            if (x1 == x2 && y1 == y2) break;
-            
-            int e2 = 2 * err;
-            if (e2 >= dy) {
-                err += dy;
-                x1 += sx;
-            }
-            if (e2 <= dx) {
-                err += dx;
-                y1 += sy;
-            }
-        }
     }
     return 0;
 }
@@ -197,10 +127,9 @@ static int l_update(State* L) {
 static std::unordered_map<std::string, lua_CFunction> methods {
     {"at", lua::wrap<l_at>},
     {"set", lua::wrap<l_set>},
-    {"clear", lua::wrap<l_clear>},
     {"line", lua::wrap<l_line>},
-    {"update", lua::wrap<l_update>}
+    {"clear", lua::wrap<l_clear>},
-};
+    {"update", lua::wrap<l_update>}};
 
 static int l_meta_index(State* L) {
     auto texture = touserdata<LuaCanvas>(L, 1);
@@ -237,9 +166,7 @@ static int l_meta_newindex(State* L) {
     if (isnumber(L, 2) && isnumber(L, 3)) {
         if (auto pixel = get_at(data, static_cast<uint>(tointeger(L, 2)))) {
             pixel->rgba = static_cast<uint>(tointeger(L, 3));
-            return 1;
         }
-        return 1;
     }
     return 0;
 }