From a5596ed5cd65bc62b983ec9dff3263beeced2dd7 Mon Sep 17 00:00:00 2001 From: MihailRis Date: Sat, 18 Jul 2026 13:25:04 +0300 Subject: [PATCH] fix canvas:line lines clipping --- src/graphics/core/ImageData.cpp | 121 +++++++++++++----- .../lua/usertypes/lua_type_canvas.cpp | 11 +- 2 files changed, 93 insertions(+), 39 deletions(-) diff --git a/src/graphics/core/ImageData.cpp b/src/graphics/core/ImageData.cpp index 6875d7ab9..5f7761188 100644 --- a/src/graphics/core/ImageData.cpp +++ b/src/graphics/core/ImageData.cpp @@ -1,5 +1,7 @@ #include "ImageData.hpp" +#include "debug/Logger.hpp" + #include #include #include @@ -7,6 +9,8 @@ #include #include +static debug::Logger logger("image-data"); + ImageData::ImageData(ImageFormat format, uint width, uint height) : format(format), width(width), height(height) { size_t pixsize; @@ -106,47 +110,83 @@ std::unique_ptr ImageData::cropped(int x, int y, int width, int heigh return subImage; } -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; +static bool clip_line( + int& x0, int& y0, int& x1, int& y1, int width, int height +) { + if (width <= 0 || height <= 0) { + return false; + } + constexpr int INSIDE = 0; + constexpr int LEFT = 1; + constexpr int RIGHT = 2; + constexpr int BOTTOM = 4; + constexpr int TOP = 8; - int dx = x2 - x1; - int dy = y2 - y1; + const int xmin = 0; + const int ymin = 0; + const int xmax = width - 1; + const int ymax = height - 1; - float t0 = 0.0f; - float t1 = 1.0f; + auto outcode = [&](int x, int y) { + int code = INSIDE; - auto clip = [](int p, int q, float& t0, float& t1) { - if (p == 0) { - return q >= 0; - } - float t = static_cast(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 (x < xmin) + code |= LEFT; + else if (x > xmax) + code |= RIGHT; + + if (y < ymin) + code |= BOTTOM; + else if (y > ymax) + code |= TOP; + + return code; }; - 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; + int c0 = outcode(x0, y0); + int c1 = outcode(x1, y1); - if (t1 < 1.0f) { - x2 = x1 + static_cast(std::round(t1 * dx)); - y2 = y1 + static_cast(std::round(t1 * dy)); + while (true) { + if (!(c0 | c1)) { + return true; + } + if (c0 & c1) { + return false; + } + + const int out = c0 ? c0 : c1; + + double x = 0.0; + double y = 0.0; + + if (out & TOP) { + y = ymax; + x = x0 + (x1 - x0) * static_cast(ymax - y0) / (y1 - y0); + } else if (out & BOTTOM) { + y = ymin; + x = x0 + (x1 - x0) * static_cast(ymin - y0) / (y1 - y0); + } else if (out & RIGHT) { + x = xmax; + y = y0 + (y1 - y0) * static_cast(xmax - x0) / (x1 - x0); + } else { // LEFT + x = xmin; + y = y0 + (y1 - y0) * static_cast(xmin - x0) / (x1 - x0); + } + + if (out == c0) { + x0 = std::clamp(static_cast(std::lround(x)), xmin, xmax); + y0 = std::clamp(static_cast(std::lround(y)), ymin, ymax); + c0 = outcode(x0, y0); + } else { + x1 = std::clamp(static_cast(std::lround(x)), xmin, xmax); + y1 = std::clamp(static_cast(std::lround(y)), ymin, ymax); + c1 = outcode(x1, y1); + } } - if (t0 > 0.0f) { - x1 = x1 + static_cast(std::round(t0 * dx)); - y1 = y1 + static_cast(std::round(t0 * dy)); - } - return true; +} + +static bool is_point_outside(int x, int y, int width, int height) { + return x < 0 || y < 0 || x >= width || y >= height; } template @@ -155,11 +195,24 @@ static void draw_line(ImageData& image, int x1, int y1, int x2, int y2, const gl uint width = image.getWidth(); uint height = image.getHeight(); + glm::ivec4 init {x1, y1, x2, y2}; + 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; } + // spam info for bug report + if (is_point_outside(x1, y1, width, height) || is_point_outside(x2, y2, width, height)) { + logger.warning() << "clip_line fault: [" << init.x << ", " << init.y + << "] - [" << init.z << ", " << init.w << "] --> [" + << x1 << ", " << y1 << "] - [" << x2 << ", " << y2 + << "]"; + x1 = glm::clamp(x1, 0, static_cast(width) - 1); + y1 = glm::clamp(y1, 0, static_cast(height) - 1); + x2 = glm::clamp(x2, 0, static_cast(width) - 1); + y2 = glm::clamp(y2, 0, static_cast(height) - 1); + } int dx = std::abs(x2 - x1); int dy = -std::abs(y2 - y1); diff --git a/src/logic/scripting/lua/usertypes/lua_type_canvas.cpp b/src/logic/scripting/lua/usertypes/lua_type_canvas.cpp index 37c53abd9..c670e23df 100644 --- a/src/logic/scripting/lua/usertypes/lua_type_canvas.cpp +++ b/src/logic/scripting/lua/usertypes/lua_type_canvas.cpp @@ -81,16 +81,17 @@ union RGBA { uint8_t arr[4]; uint32_t rgba; }; +static_assert(sizeof(RGBA) == 4); -static RGBA* get_at(const ImageData& data, uint index) { - if (index >= data.getWidth() * data.getHeight()) { - return nullptr; - } +static RGBA* get_at(const ImageData& data, size_t index) { return reinterpret_cast(data.getData() + index * sizeof(RGBA)); } static RGBA* get_at(const ImageData& data, uint x, uint y) { - return get_at(data, y * data.getWidth() + x); + if (x >= data.getWidth() || y >= data.getHeight()) { + return nullptr; + } + return get_at(data, static_cast(y) * data.getWidth() + x); } static RGBA* get_at(State* L, uint x, uint y) {