jaildesigner-jailgames/jaildoctors_dilemma
1
0
Fork 2
Code Issues Pull Requests Projects Releases 24 Wiki Activity

surface: hallazgo 2 — drawLine con Bresenham en enteros

Browse Source 
El bucle usaba floats con comparación de igualdad exacta (x1==x2 &&
y1==y2) como condición de parada, con incrementos ±1.0f acumulados:
bug latente. Convertidos los endpoints de entrada con std::lround y
reescrito el algoritmo con ints. Firma pública float preservada para
no tocar callers.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
This commit is contained in:
Sergio
2026-04-18 11:55:12 +02:00
parent b1413bbf8a
commit 1f5b1ad1ab
1 changed files with 22 additions and 21 deletions
Download Patch File Download Diff File Expand all files Collapse all files

43
source/core/rendering/surface.cpp
View File

@@ -211,37 +211,38 @@ void Surface::drawRectBorder(const SDL_FRect* rect, Uint8 color) { // NOLINT(re
} }
} }
// Dibuja una linea // Dibuja una linea (Bresenham en enteros)
void Surface::drawLine(float x1, float y1, float x2, float y2, Uint8 color) { // NOLINT(readability-convert-member-functions-to-static) void Surface::drawLine(float x1, float y1, float x2, float y2, Uint8 color) { // NOLINT(readability-convert-member-functions-to-static)
// Calcula las diferencias int ix1 = static_cast<int>(std::lround(x1));
float dx = std::abs(x2 - x1); int iy1 = static_cast<int>(std::lround(y1));
float dy = std::abs(y2 - y1); const int IX2 = static_cast<int>(std::lround(x2));
const int IY2 = static_cast<int>(std::lround(y2));
// Determina la dirección del incremento const int DX = std::abs(IX2 - ix1);
float sx = (x1 < x2) ? 1 : -1; const int DY = std::abs(IY2 - iy1);
float sy = (y1 < y2) ? 1 : -1; const int SX = (ix1 < IX2) ? 1 : -1;
const int SY = (iy1 < IY2) ? 1 : -1;
float err = dx - dy; const int SURF_W = static_cast<int>(surface_data_->width);
const int SURF_H = static_cast<int>(surface_data_->height);
Uint8* data_ptr = surface_data_->data.get();
int err = DX - DY;
while (true) { while (true) {
// Asegúrate de no dibujar fuera de los límites de la superficie if (ix1 >= 0 && ix1 < SURF_W && iy1 >= 0 && iy1 < SURF_H) {
if (x1 >= 0 && x1 < surface_data_->width && y1 >= 0 && y1 < surface_data_->height) { data_ptr[ix1 + (iy1 * SURF_W)] = color;
surface_data_->data.get()[static_cast<size_t>(x1 + (y1 * surface_data_->width))] = color;
} }
if (ix1 == IX2 && iy1 == IY2) {
// Si alcanzamos el punto final, salimos
if (x1 == x2 && y1 == y2) {
break; break;
} }
int e2 = 2 * err; int e2 = 2 * err;
if (e2 > -dy) { if (e2 > -DY) {
err -= dy; err -= DY;
x1 += sx; ix1 += SX;
} }
if (e2 < dx) { if (e2 < DX) {
err += dx; err += DX;
y1 += sy; iy1 += SY;
} }
} }
} }