A fork of https://github.com/crosspoint-reader/crosspoint-reader
fix: add bresenham for arbitrary lines (#923)
## Summary
* GfxRender did handle horizontal and vertical lines but had a TODO for
arbitrary lines.
* Added integer based Bresenham line drawing
## Additional Context
---
### AI Usage
While CrossPoint doesn't have restrictions on AI tools in contributing,
please be transparent about their usage as it
helps set the right context for reviewers.
Did you use AI tools to help write this code? _**NO**_
+22
-2
+22
-2
lib/GfxRenderer/GfxRenderer.cpp
+22
-2
lib/GfxRenderer/GfxRenderer.cpp
···
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drawPixel(x, y1, state);
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}
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} else {
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-
// TODO: Implement
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LOG_ERR("GFX", "Line drawing not supported");
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+
// Bresenham's line algorithm — integer arithmetic only
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int dx = x2 - x1;
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int dy = y2 - y1;
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int sx = (dx > 0) ? 1 : -1;
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int sy = (dy > 0) ? 1 : -1;
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dx = sx * dx; // abs
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dy = sy * dy; // abs
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+
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int err = dx - dy;
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while (true) {
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drawPixel(x1, y1, state);
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if (x1 == x2 && y1 == y2) break;
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int e2 = 2 * err;
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if (e2 > -dy) {
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err -= dy;
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x1 += sx;
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}
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if (e2 < dx) {
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err += dx;
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y1 += sy;
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}
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}
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}
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}
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