diff options
Diffstat (limited to 'SharedGraphics')
| -rw-r--r-- | SharedGraphics/Painter.cpp | 73 |
1 files changed, 49 insertions, 24 deletions
diff --git a/SharedGraphics/Painter.cpp b/SharedGraphics/Painter.cpp index 34b872d429..c713415841 100644 --- a/SharedGraphics/Painter.cpp +++ b/SharedGraphics/Painter.cpp @@ -478,6 +478,8 @@ void Painter::set_pixel(const Point& p, Color color) void Painter::draw_line(const Point& p1, const Point& p2, Color color) { + auto clip_rect = this->clip_rect(); + auto point1 = p1; point1.move_by(state().translation); @@ -487,37 +489,34 @@ void Painter::draw_line(const Point& p1, const Point& p2, Color color) // Special case: vertical line. if (point1.x() == point2.x()) { const int x = point1.x(); - if (x < clip_rect().left() || x > clip_rect().right()) + if (x < clip_rect.left() || x > clip_rect.right()) return; if (point1.y() > point2.y()) swap(point1, point2); - if (point1.y() > clip_rect().bottom()) + if (point1.y() > clip_rect.bottom()) return; - if (point2.y() < clip_rect().top()) + if (point2.y() < clip_rect.top()) return; - int min_y = max(point1.y(), clip_rect().top()); - int max_y = min(point2.y(), clip_rect().bottom()); + int min_y = max(point1.y(), clip_rect.top()); + int max_y = min(point2.y(), clip_rect.bottom()); for (int y = min_y; y <= max_y; ++y) set_pixel_with_draw_op(m_target->scanline(y)[x], color); return; } - if (point1.x() > point2.x()) - swap(point1, point2); - // Special case: horizontal line. if (point1.y() == point2.y()) { const int y = point1.y(); - if (y < clip_rect().top() || y > clip_rect().bottom()) + if (y < clip_rect.top() || y > clip_rect.bottom()) return; if (point1.x() > point2.x()) swap(point1, point2); - if (point1.x() > clip_rect().right()) + if (point1.x() > clip_rect.right()) return; - if (point2.x() < clip_rect().left()) + if (point2.x() < clip_rect.left()) return; - int min_x = max(point1.x(), clip_rect().left()); - int max_x = min(point2.x(), clip_rect().right()); + int min_x = max(point1.x(), clip_rect.left()); + int max_x = min(point2.x(), clip_rect.right()); auto* pixels = m_target->scanline(point1.y()); if (draw_op() == DrawOp::Copy) { fast_dword_fill(pixels + min_x, color.value(), max_x - min_x + 1); @@ -528,21 +527,47 @@ void Painter::draw_line(const Point& p1, const Point& p2, Color color) return; } - // FIXME: Implement clipping below. + const double adx = abs(point2.x() - point1.x()); + const double ady = abs(point2.y() - point1.y()); + + if (adx > ady) { + if (point1.x() > point2.x()) + swap(point1, point2); + } else { + if (point1.y() > point2.y()) + swap(point1, point2); + } + // FIXME: Implement clipping below. const double dx = point2.x() - point1.x(); const double dy = point2.y() - point1.y(); - const double delta_error = fabs(dy / dx); double error = 0; - const double y_step = dy == 0 ? 0 : (dy > 0 ? 1 : -1); - - int y = point1.y(); - for (int x = point1.x(); x <= point2.x(); ++x) { - m_target->scanline(y)[x] = color.value(); - error += delta_error; - if (error >= 0.5) { - y = (double)y + y_step; - error -= 1.0; + + if (dx > dy) { + const double y_step = dy == 0 ? 0 : (dy > 0 ? 1 : -1); + const double delta_error = fabs(dy / dx); + int y = point1.y(); + for (int x = point1.x(); x <= point2.x(); ++x) { + if (clip_rect.contains(x, y)) + m_target->scanline(y)[x] = color.value(); + error += delta_error; + if (error >= 0.5) { + y = (double)y + y_step; + error -= 1.0; + } + } + } else { + const double x_step = dx == 0 ? 0 : (dx > 0 ? 1 : -1); + const double delta_error = fabs(dx / dy); + int x = point1.x(); + for (int y = point1.y(); y <= point2.y(); ++y) { + if (clip_rect.contains(x, y)) + m_target->scanline(y)[x] = color.value(); + error += delta_error; + if (error >= 0.5) { + x = (double)x + x_step; + error -= 1.0; + } } } } |