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Spacewar
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The star is now tied to the mouse, just for fun.

This commit is contained in:
Barra Ó Catháin 2023-03-15 23:43:42 +00:00
parent dcbf5b8ae2
commit 9402a97ab7
1 changed files with 23 additions and 11 deletions
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30
Spacewar.c
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@ -1,4 +1,4 @@
// SDL Experiment 07, Barra Ó Catháin.
// SDL Experiment 08, Barra Ó Catháin.
// ===================================
#include <SDL2/SDL.h>
#include <SDL2/SDL_timer.h>
@ -90,11 +90,11 @@ int main(int argc, char ** argv)
{
SDL_Event event;
bool quit = false;
int width = 0, height = 0;
long positionX = 0, positionY = 0;
int width = 0, height = 0, mouseX = 0, mouseY = 0;
uint32_t rendererFlags = SDL_RENDERER_ACCELERATED;
double deltaTime = 0, gravityMagnitude = 0, gravityAcceleration = 0;
uint64_t thisFrameTime = SDL_GetPerformanceCounter(), lastFrameTime = 0;
long positionX = 0, positionY = 0;
xyVector positionVector = {100, 100}, velocityVector = {20, 0}, gravityVector = {0, 0};
// Initialize the SDL library, video, sound, and input:
@ -136,16 +136,25 @@ int main(int argc, char ** argv)
// Store the window's current width and height:
SDL_GetWindowSize(window, &width, &height);
// Store the mouse pointer's current position in the window:
SDL_GetMouseState(&mouseX, &mouseY);
// Calculate the vector between the star and ship:
xyVectorBetweenPoints(positionVector.xComponent, positionVector.yComponent, width/2, height/2, &gravityVector);
xyVectorBetweenPoints(positionVector.xComponent, positionVector.yComponent, mouseX, mouseY, &gravityVector);
// Make it into a unit vector:
gravityMagnitude = normalizeXYVector(&gravityVector);
// Calculate the gravity between the star and ship:
gravityAcceleration = (gravityMagnitude > 15) ?
2 * (2500 / pow(gravityMagnitude, 2)):
0.02 * (2500 / pow(gravityMagnitude, 2));
if(gravityMagnitude > 45)
{
gravityAcceleration = 2 * (2500 / pow(gravityMagnitude, 2));
}
else
{
gravityAcceleration = 0;
multiplyXYVector(&velocityVector, -0.98);
}
// Scale the vector:
multiplyXYVector(&gravityVector, gravityAcceleration);
@ -197,7 +206,7 @@ int main(int argc, char ** argv)
SDL_SetRenderDrawColor(renderer, 255, 255, 0, 255);
// Draw a circle in the center as the star:
DrawCircle(renderer, width/2, height/2, 30);
DrawCircle(renderer, mouseX, mouseY, 30);
// Draw a line representing the velocity:
SDL_RenderDrawLine(renderer, positionX, positionY,
@ -206,10 +215,13 @@ int main(int argc, char ** argv)
// Present the rendered graphics:
SDL_RenderPresent(renderer);
// Delay enough so that we run at 60 frames:
SDL_Delay(1000 / 144);
}
return 0;
}
// ===========================================================================================
// Local Variables:
// compile-command: "gcc `sdl2-config --libs --cflags` SDL2-Experiment-07.c -lm"
// compile-command: "gcc `sdl2-config --libs --cflags` SDL2-Experiment-08.c -lm"
// End: