Added a second ship to the simulation.
Before Width: | Height: | Size: 6.5 KiB After Width: | Height: | Size: 6.5 KiB |
Before Width: | Height: | Size: 1023 B After Width: | Height: | Size: 1023 B |
Before Width: | Height: | Size: 992 B After Width: | Height: | Size: 992 B |
Before Width: | Height: | Size: 1004 B After Width: | Height: | Size: 1004 B |
Before Width: | Height: | Size: 981 B After Width: | Height: | Size: 981 B |
280
Spacewar.c
|
@ -1,4 +1,4 @@
|
||||||
// SDL Experiment 12, Barra Ó Catháin.
|
// SDL Experiment 13, Barra Ó Catháin.
|
||||||
// ===================================
|
// ===================================
|
||||||
#include <SDL2/SDL.h>
|
#include <SDL2/SDL.h>
|
||||||
#include <SDL2/SDL_image.h>
|
#include <SDL2/SDL_image.h>
|
||||||
|
@ -7,12 +7,22 @@
|
||||||
#include <stdbool.h>
|
#include <stdbool.h>
|
||||||
#include <stdint.h>
|
#include <stdint.h>
|
||||||
|
|
||||||
|
// A 2D vector:
|
||||||
typedef struct xyVector
|
typedef struct xyVector
|
||||||
{
|
{
|
||||||
double xComponent;
|
double xComponent;
|
||||||
double yComponent;
|
double yComponent;
|
||||||
} xyVector;
|
} xyVector;
|
||||||
|
|
||||||
|
// A struct storing the needed data to draw a ship:
|
||||||
|
typedef struct ship
|
||||||
|
{
|
||||||
|
SDL_Rect rectangle;
|
||||||
|
xyVector position;
|
||||||
|
xyVector velocity;
|
||||||
|
xyVector gravity;
|
||||||
|
} ship;
|
||||||
|
|
||||||
// Calculate the vector from point A to point B:
|
// Calculate the vector from point A to point B:
|
||||||
static inline void xyVectorBetweenPoints(long ax, long ay, long bx, long by, xyVector * vector)
|
static inline void xyVectorBetweenPoints(long ax, long ay, long bx, long by, xyVector * vector)
|
||||||
{
|
{
|
||||||
|
@ -24,8 +34,11 @@ static inline void xyVectorBetweenPoints(long ax, long ay, long bx, long by, xyV
|
||||||
static inline double normalizeXYVector(xyVector * vector)
|
static inline double normalizeXYVector(xyVector * vector)
|
||||||
{
|
{
|
||||||
double magnitude = sqrt(pow(vector->xComponent, 2) + pow(vector->yComponent, 2));
|
double magnitude = sqrt(pow(vector->xComponent, 2) + pow(vector->yComponent, 2));
|
||||||
vector->xComponent /= magnitude;
|
if(magnitude != 0)
|
||||||
vector->yComponent /= magnitude;
|
{
|
||||||
|
vector->xComponent /= magnitude;
|
||||||
|
vector->yComponent /= magnitude;
|
||||||
|
}
|
||||||
return magnitude;
|
return magnitude;
|
||||||
}
|
}
|
||||||
|
|
||||||
|
@ -38,6 +51,7 @@ static inline double angleBetweenVectors(xyVector * vectorA, xyVector * vectorB)
|
||||||
return atan2(dotProduct, determinant) / 0.01745329;
|
return atan2(dotProduct, determinant) / 0.01745329;
|
||||||
}
|
}
|
||||||
|
|
||||||
|
// Rotate XY vector by a given number of degrees:
|
||||||
static inline void rotateXYVector(xyVector * vector, double degrees)
|
static inline void rotateXYVector(xyVector * vector, double degrees)
|
||||||
{
|
{
|
||||||
double xComponent = vector->xComponent, yComponent = vector->yComponent;
|
double xComponent = vector->xComponent, yComponent = vector->yComponent;
|
||||||
|
@ -65,42 +79,94 @@ static inline void multiplyXYVector(xyVector * vector, double scalar)
|
||||||
vector->xComponent *= scalar;
|
vector->xComponent *= scalar;
|
||||||
vector->yComponent *= scalar;
|
vector->yComponent *= scalar;
|
||||||
}
|
}
|
||||||
|
|
||||||
void DrawCircle(SDL_Renderer * renderer, int32_t centreX, int32_t centreY, int32_t radius)
|
void DrawCircle(SDL_Renderer * renderer, int32_t centreX, int32_t centreY, int32_t radius)
|
||||||
{
|
{
|
||||||
const int32_t diameter = (radius * 2);
|
const int32_t diameter = (radius * 2);
|
||||||
|
|
||||||
int32_t x = (radius - 1);
|
int32_t x = (radius - 1);
|
||||||
int32_t y = 0;
|
int32_t y = 0;
|
||||||
int32_t tx = 1;
|
int32_t tx = 1;
|
||||||
int32_t ty = 1;
|
int32_t ty = 1;
|
||||||
int32_t error = (tx - diameter);
|
int32_t error = (tx - diameter);
|
||||||
|
|
||||||
while (x >= y)
|
while (x >= y)
|
||||||
{
|
{
|
||||||
// Each of the following renders an octant of the circle
|
// Each of the following renders an octant of the circle
|
||||||
SDL_RenderDrawPoint(renderer, centreX + x, centreY - y);
|
SDL_RenderDrawPoint(renderer, centreX + x, centreY - y);
|
||||||
SDL_RenderDrawPoint(renderer, centreX + x, centreY + y);
|
SDL_RenderDrawPoint(renderer, centreX + x, centreY + y);
|
||||||
SDL_RenderDrawPoint(renderer, centreX - x, centreY - y);
|
SDL_RenderDrawPoint(renderer, centreX - x, centreY - y);
|
||||||
SDL_RenderDrawPoint(renderer, centreX - x, centreY + y);
|
SDL_RenderDrawPoint(renderer, centreX - x, centreY + y);
|
||||||
SDL_RenderDrawPoint(renderer, centreX + y, centreY - x);
|
SDL_RenderDrawPoint(renderer, centreX + y, centreY - x);
|
||||||
SDL_RenderDrawPoint(renderer, centreX + y, centreY + x);
|
SDL_RenderDrawPoint(renderer, centreX + y, centreY + x);
|
||||||
SDL_RenderDrawPoint(renderer, centreX - y, centreY - x);
|
SDL_RenderDrawPoint(renderer, centreX - y, centreY - x);
|
||||||
SDL_RenderDrawPoint(renderer, centreX - y, centreY + x);
|
SDL_RenderDrawPoint(renderer, centreX - y, centreY + x);
|
||||||
|
|
||||||
if (error <= 0)
|
if (error <= 0)
|
||||||
{
|
{
|
||||||
++y;
|
++y;
|
||||||
error += ty;
|
error += ty;
|
||||||
ty += 2;
|
ty += 2;
|
||||||
}
|
}
|
||||||
|
|
||||||
if (error > 0)
|
if (error > 0)
|
||||||
{
|
{
|
||||||
--x;
|
--x;
|
||||||
tx += 2;
|
tx += 2;
|
||||||
error += (tx - diameter);
|
error += (tx - diameter);
|
||||||
}
|
}
|
||||||
}
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
void calculateGravity(xyVector * starPosition, ship * shipUnderGravity)
|
||||||
|
{
|
||||||
|
// Calculate the vector between the star and ship:
|
||||||
|
xyVectorBetweenPoints(shipUnderGravity->position.xComponent, shipUnderGravity->position.yComponent,
|
||||||
|
starPosition->xComponent, starPosition->yComponent, &shipUnderGravity->gravity);
|
||||||
|
|
||||||
|
// Make it into a unit vector:
|
||||||
|
double gravityMagnitude = normalizeXYVector(&shipUnderGravity->gravity);
|
||||||
|
double gravityAcceleration = 0;
|
||||||
|
|
||||||
|
// Calculate the gravity between the star and ship:
|
||||||
|
if(gravityMagnitude != 0)
|
||||||
|
{
|
||||||
|
if(gravityMagnitude >= 116)
|
||||||
|
{
|
||||||
|
gravityAcceleration = 0.1 * (35000 / (pow(gravityMagnitude, 2)));
|
||||||
|
}
|
||||||
|
else
|
||||||
|
{
|
||||||
|
gravityAcceleration = 0;
|
||||||
|
}
|
||||||
|
}
|
||||||
|
else
|
||||||
|
{
|
||||||
|
gravityAcceleration = 1;
|
||||||
|
}
|
||||||
|
|
||||||
|
if(gravityAcceleration < 0.01)
|
||||||
|
{
|
||||||
|
gravityAcceleration = 0.01;
|
||||||
|
}
|
||||||
|
|
||||||
|
// Scale the vector:
|
||||||
|
multiplyXYVector(&shipUnderGravity->gravity, gravityAcceleration);
|
||||||
|
}
|
||||||
|
|
||||||
|
// Create a ship with the given parameters:
|
||||||
|
ship createShip(int width, int height, double positionX, double positionY, double velocityX, double velocityY)
|
||||||
|
{
|
||||||
|
ship newShip;
|
||||||
|
newShip.rectangle.w = width;
|
||||||
|
newShip.rectangle.h = height;
|
||||||
|
newShip.position.xComponent = positionX;
|
||||||
|
newShip.position.yComponent = positionY;
|
||||||
|
newShip.velocity.xComponent = velocityX;
|
||||||
|
newShip.velocity.yComponent = velocityY;
|
||||||
|
newShip.gravity.xComponent = 0;
|
||||||
|
newShip.gravity.yComponent = 0;
|
||||||
|
return newShip;
|
||||||
}
|
}
|
||||||
|
|
||||||
int main(int argc, char ** argv)
|
int main(int argc, char ** argv)
|
||||||
|
@ -112,8 +178,13 @@ int main(int argc, char ** argv)
|
||||||
long positionX = 512, positionY = 512, starPositionX = 0, starPositionY = 0;
|
long positionX = 512, positionY = 512, starPositionX = 0, starPositionY = 0;
|
||||||
double deltaTime = 0, gravityMagnitude = 0, gravityAcceleration = 0, frameAccumulator = 0;
|
double deltaTime = 0, gravityMagnitude = 0, gravityAcceleration = 0, frameAccumulator = 0;
|
||||||
bool quit = false, rotatingClockwise = false, rotatingAnticlockwise = false, accelerating = false;
|
bool quit = false, rotatingClockwise = false, rotatingAnticlockwise = false, accelerating = false;
|
||||||
xyVector positionVector = {512, 512}, velocityVector = {1, 0}, gravityVector = {0, 0}, engineVector = {0.16, 0}, upVector = {0, 0.1};
|
xyVector positionVector = {512, 512}, velocityVector = {1, 0}, gravityVector = {0, 0},
|
||||||
|
engineVector = {0.04, 0}, upVector = {0, 0.1}, starPosition = {0, 0};
|
||||||
|
|
||||||
|
// Get the initial
|
||||||
|
ship shipA = createShip(32, 32, 512, 512, 1, 0);
|
||||||
|
ship shipB = createShip(32, 32, -512, -512, 0, 1);
|
||||||
|
|
||||||
// Initialize the SDL library, video, sound, and input:
|
// Initialize the SDL library, video, sound, and input:
|
||||||
if (SDL_Init(SDL_INIT_EVERYTHING) != 0)
|
if (SDL_Init(SDL_INIT_EVERYTHING) != 0)
|
||||||
{
|
{
|
||||||
|
@ -123,12 +194,7 @@ int main(int argc, char ** argv)
|
||||||
// Initialize image loading:
|
// Initialize image loading:
|
||||||
IMG_Init(IMG_INIT_PNG);
|
IMG_Init(IMG_INIT_PNG);
|
||||||
SDL_SetHint(SDL_HINT_RENDER_SCALE_QUALITY, "2");
|
SDL_SetHint(SDL_HINT_RENDER_SCALE_QUALITY, "2");
|
||||||
|
|
||||||
// Create a rectangle to put the ship in:
|
|
||||||
SDL_Rect shipRect;
|
|
||||||
shipRect.w = 32;
|
|
||||||
shipRect.h = 32;
|
|
||||||
|
|
||||||
// Create an SDL window and rendering context in that window:
|
// Create an SDL window and rendering context in that window:
|
||||||
SDL_Window * window = SDL_CreateWindow("SDL_TEST", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, 700, 700, 0);
|
SDL_Window * window = SDL_CreateWindow("SDL_TEST", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, 700, 700, 0);
|
||||||
SDL_Renderer * renderer = SDL_CreateRenderer(window, -1, rendererFlags);
|
SDL_Renderer * renderer = SDL_CreateRenderer(window, -1, rendererFlags);
|
||||||
|
@ -137,11 +203,11 @@ int main(int argc, char ** argv)
|
||||||
SDL_Texture * idleTexture, * acceleratingTexture, * clockwiseTexture, * anticlockwiseTexture, * currentTexture,
|
SDL_Texture * idleTexture, * acceleratingTexture, * clockwiseTexture, * anticlockwiseTexture, * currentTexture,
|
||||||
* acceleratingTexture2;
|
* acceleratingTexture2;
|
||||||
|
|
||||||
idleTexture = IMG_LoadTexture(renderer, "./Experiment-12-Images/Ship-Idle.png");
|
idleTexture = IMG_LoadTexture(renderer, "./Experiment-13-Images/Ship-Idle.png");
|
||||||
clockwiseTexture = IMG_LoadTexture(renderer, "./Experiment-12-Images/Ship-Clockwise.png");
|
clockwiseTexture = IMG_LoadTexture(renderer, "./Experiment-13-Images/Ship-Clockwise.png");
|
||||||
acceleratingTexture = IMG_LoadTexture(renderer, "./Experiment-12-Images/Ship-Accelerating.png");
|
acceleratingTexture = IMG_LoadTexture(renderer, "./Experiment-13-Images/Ship-Accelerating.png");
|
||||||
anticlockwiseTexture = IMG_LoadTexture(renderer, "./Experiment-12-Images/Ship-Anticlockwise.png");
|
anticlockwiseTexture = IMG_LoadTexture(renderer, "./Experiment-13-Images/Ship-Anticlockwise.png");
|
||||||
acceleratingTexture2 = IMG_LoadTexture(renderer, "./Experiment-12-Images/Ship-Accelerating-Frame-2.png");
|
acceleratingTexture2 = IMG_LoadTexture(renderer, "./Experiment-13-Images/Ship-Accelerating-Frame-2.png");
|
||||||
|
|
||||||
// Enable resizing the window:
|
// Enable resizing the window:
|
||||||
SDL_SetWindowResizable(window, SDL_TRUE);
|
SDL_SetWindowResizable(window, SDL_TRUE);
|
||||||
|
@ -157,7 +223,7 @@ int main(int argc, char ** argv)
|
||||||
{
|
{
|
||||||
switch (event.type)
|
switch (event.type)
|
||||||
{
|
{
|
||||||
case SDL_QUIT:
|
case SDL_QUIT:
|
||||||
{
|
{
|
||||||
quit = true;
|
quit = true;
|
||||||
break;
|
break;
|
||||||
|
@ -222,62 +288,55 @@ int main(int argc, char ** argv)
|
||||||
}
|
}
|
||||||
}
|
}
|
||||||
|
|
||||||
// Wrap the position if the ship goes interstellar:
|
// Wrap the positions if the ship goes interstellar:
|
||||||
if(positionVector.xComponent > 4096)
|
if(shipA.position.xComponent > 4096)
|
||||||
{
|
{
|
||||||
positionVector.xComponent = -2000;
|
shipA.position.xComponent = -2000;
|
||||||
velocityVector.xComponent *= 0.9;
|
shipA.velocity.xComponent *= 0.9;
|
||||||
}
|
}
|
||||||
else if(positionVector.xComponent < -4096)
|
else if(shipA.position.xComponent < -4096)
|
||||||
{
|
{
|
||||||
positionVector.xComponent = 2000;
|
shipA.position.xComponent = 2000;
|
||||||
velocityVector.xComponent *= 0.9;
|
shipA.velocity.xComponent *= 0.9;
|
||||||
|
}
|
||||||
|
if(shipA.position.yComponent > 4096)
|
||||||
|
{
|
||||||
|
shipA.position.yComponent = -2000;
|
||||||
|
shipA.velocity.yComponent *= 0.9;
|
||||||
|
}
|
||||||
|
else if(shipA.position.yComponent < -4096)
|
||||||
|
{
|
||||||
|
shipA.position.yComponent = 2000;
|
||||||
|
shipA.velocity.yComponent *= 0.9;
|
||||||
}
|
}
|
||||||
|
|
||||||
if(positionVector.yComponent > 4096)
|
if(shipB.position.xComponent > 4096)
|
||||||
{
|
{
|
||||||
positionVector.yComponent = -2000;
|
shipB.position.xComponent = -2000;
|
||||||
velocityVector.yComponent *= 0.9;
|
shipB.velocity.xComponent *= 0.9;
|
||||||
}
|
}
|
||||||
else if(positionVector.yComponent < -4096)
|
else if(shipB.position.xComponent < -4096)
|
||||||
{
|
{
|
||||||
positionVector.yComponent = 2000;
|
shipB.position.xComponent = 2000;
|
||||||
velocityVector.yComponent *= 0.9;
|
shipB.velocity.xComponent *= 0.9;
|
||||||
}
|
}
|
||||||
|
if(shipB.position.yComponent > 4096)
|
||||||
|
{
|
||||||
|
shipB.position.yComponent = -2000;
|
||||||
|
shipB.velocity.yComponent *= 0.9;
|
||||||
|
}
|
||||||
|
else if(shipB.position.yComponent < -4096)
|
||||||
|
{
|
||||||
|
shipB.position.yComponent = 2000;
|
||||||
|
shipB.velocity.yComponent *= 0.9;
|
||||||
|
}
|
||||||
|
|
||||||
// Store the window's current width and height:
|
// Store the window's current width and height:
|
||||||
SDL_GetWindowSize(window, &width, &height);
|
SDL_GetWindowSize(window, &width, &height);
|
||||||
|
|
||||||
// Calculate the vector between the star and ship:
|
// Calculate the gravity for the ships:
|
||||||
xyVectorBetweenPoints(positionVector.xComponent, positionVector.yComponent, starPositionX, starPositionY, &gravityVector);
|
calculateGravity(&starPosition, &shipA);
|
||||||
|
calculateGravity(&starPosition, &shipB);
|
||||||
// Make it into a unit vector:
|
|
||||||
gravityMagnitude = normalizeXYVector(&gravityVector);
|
|
||||||
|
|
||||||
// Calculate the gravity between the star and ship:
|
|
||||||
if(gravityMagnitude != 0)
|
|
||||||
{
|
|
||||||
if(gravityMagnitude >= 215)
|
|
||||||
{
|
|
||||||
gravityAcceleration = 10 * (9000 / (pow(gravityMagnitude, 2)));
|
|
||||||
}
|
|
||||||
else
|
|
||||||
{
|
|
||||||
gravityAcceleration = 0.5 * (5000 / (pow(gravityMagnitude, 2)));
|
|
||||||
}
|
|
||||||
}
|
|
||||||
else
|
|
||||||
{
|
|
||||||
gravityAcceleration = 1;
|
|
||||||
}
|
|
||||||
|
|
||||||
if(gravityAcceleration < 0.01)
|
|
||||||
{
|
|
||||||
gravityAcceleration = 0.01;
|
|
||||||
}
|
|
||||||
|
|
||||||
// Scale the vector:
|
|
||||||
multiplyXYVector(&gravityVector, gravityAcceleration);
|
|
||||||
|
|
||||||
// Set the texture to idle:
|
// Set the texture to idle:
|
||||||
currentTexture = idleTexture;
|
currentTexture = idleTexture;
|
||||||
|
@ -295,10 +354,12 @@ int main(int argc, char ** argv)
|
||||||
}
|
}
|
||||||
|
|
||||||
// Calculate the new current velocity:
|
// Calculate the new current velocity:
|
||||||
addXYVectorDeltaScaled(&velocityVector, &gravityVector, deltaTime);
|
addXYVectorDeltaScaled(&shipA.velocity, &shipA.gravity, deltaTime);
|
||||||
|
addXYVectorDeltaScaled(&shipB.velocity, &shipB.gravity, deltaTime);
|
||||||
|
|
||||||
if(accelerating)
|
if(accelerating)
|
||||||
{
|
{
|
||||||
addXYVectorDeltaScaled(&velocityVector, &engineVector, deltaTime);
|
addXYVectorDeltaScaled(&shipA.velocity, &engineVector, deltaTime);
|
||||||
frameAccumulator += deltaTime;
|
frameAccumulator += deltaTime;
|
||||||
currentTexture = acceleratingTexture;
|
currentTexture = acceleratingTexture;
|
||||||
if((long)frameAccumulator % 4)
|
if((long)frameAccumulator % 4)
|
||||||
|
@ -308,14 +369,15 @@ int main(int argc, char ** argv)
|
||||||
}
|
}
|
||||||
|
|
||||||
// Calculate the new position:
|
// Calculate the new position:
|
||||||
addXYVectorDeltaScaled(&positionVector, &velocityVector, deltaTime);
|
addXYVectorDeltaScaled(&shipA.position, &shipA.velocity, deltaTime);
|
||||||
|
addXYVectorDeltaScaled(&shipB.position, &shipB.velocity, deltaTime);
|
||||||
|
|
||||||
positionX = (long)positionVector.xComponent;
|
// Calculate the position of the sprites:
|
||||||
positionY = (long)positionVector.yComponent;
|
shipA.rectangle.x = (width/2) - 16;
|
||||||
|
shipA.rectangle.y = (height/2) - 16;
|
||||||
|
|
||||||
// Calculate the position of the sprite:
|
shipB.rectangle.x = (long)(((shipB.position.xComponent - shipA.position.xComponent) - 32) + width/2);
|
||||||
shipRect.x = (width/2) - 15;
|
shipB.rectangle.y = (long)(((shipB.position.yComponent - shipA.position.yComponent) - 32) + height/2);
|
||||||
shipRect.y = (height/2) - 15;
|
|
||||||
|
|
||||||
// Set the colour to black:
|
// Set the colour to black:
|
||||||
SDL_SetRenderDrawColor(renderer, 0, 0, 0, 255);
|
SDL_SetRenderDrawColor(renderer, 0, 0, 0, 255);
|
||||||
|
@ -324,28 +386,32 @@ int main(int argc, char ** argv)
|
||||||
SDL_RenderClear(renderer);
|
SDL_RenderClear(renderer);
|
||||||
|
|
||||||
// Draw the ship:
|
// Draw the ship:
|
||||||
SDL_RenderCopyEx(renderer, currentTexture, NULL, &shipRect, angleBetweenVectors(&engineVector, &upVector) + 90, NULL, 0);
|
SDL_RenderCopyEx(renderer, currentTexture, NULL, &shipA.rectangle,
|
||||||
|
angleBetweenVectors(&engineVector, &upVector) + 90, NULL, 0);
|
||||||
|
SDL_RenderCopyEx(renderer, currentTexture, NULL, &shipB.rectangle,
|
||||||
|
angleBetweenVectors(&shipB.velocity, &upVector) + 90, NULL, 0);
|
||||||
|
|
||||||
// Set the colour to yellow:
|
// Set the colour to yellow:
|
||||||
SDL_SetRenderDrawColor(renderer, 255, 255, 0, 255);
|
SDL_SetRenderDrawColor(renderer, 255, 255, 0, 255);
|
||||||
|
|
||||||
// Draw a circle as the star:
|
// Draw a circle as the star:
|
||||||
DrawCircle(renderer, (long)(starPositionX - positionX) + width/2, (long)(starPositionY - positionY) + height/2 , 200);
|
DrawCircle(renderer, (long)(starPositionX - shipA.position.xComponent) + width/2,
|
||||||
|
(long)(starPositionY - shipA.position.yComponent) + height/2, 50);
|
||||||
|
|
||||||
// Draw a line representing the velocity:
|
// Draw a line representing the velocity:
|
||||||
SDL_RenderDrawLine(renderer, width/2, height/2,
|
SDL_RenderDrawLine(renderer, width/2, height/2,
|
||||||
(long)((width/2) + velocityVector.xComponent * 15),
|
(long)((width/2) + shipA.velocity.xComponent * 15),
|
||||||
(long)((height/2) + velocityVector.yComponent * 15));
|
(long)((height/2) + shipA.velocity.yComponent * 15));
|
||||||
|
|
||||||
// Set the colour to blue:
|
// Set the colour to blue:
|
||||||
SDL_SetRenderDrawColor(renderer, 0, 0, 255, 255);
|
SDL_SetRenderDrawColor(renderer, 0, 0, 255, 255);
|
||||||
|
|
||||||
// Draw a line representing the direction of the star:
|
// Draw a line representing the direction of the star:
|
||||||
normalizeXYVector(&gravityVector);
|
normalizeXYVector(&shipA.gravity);
|
||||||
multiplyXYVector(&gravityVector, 100);
|
multiplyXYVector(&shipA.gravity, 100);
|
||||||
SDL_RenderDrawLine(renderer, width/2, height/2,
|
SDL_RenderDrawLine(renderer, width/2, height/2,
|
||||||
(long)((width/2) + gravityVector.xComponent),
|
(long)((width/2) + shipA.gravity.xComponent),
|
||||||
(long)((height/2) + gravityVector.yComponent));
|
(long)((height/2) + shipA.gravity.yComponent));
|
||||||
|
|
||||||
// Present the rendered graphics:
|
// Present the rendered graphics:
|
||||||
SDL_RenderPresent(renderer);
|
SDL_RenderPresent(renderer);
|
||||||
|
@ -354,5 +420,5 @@ int main(int argc, char ** argv)
|
||||||
}
|
}
|
||||||
// ===========================================================================================
|
// ===========================================================================================
|
||||||
// Local Variables:
|
// Local Variables:
|
||||||
// compile-command: "gcc `sdl2-config --libs --cflags` SDL2-Experiment-12.c -lSDL2_image -lm"
|
// compile-command: "gcc `sdl2-config --libs --cflags` SDL2-Experiment-13.c -lSDL2_image -lm"
|
||||||
// End:
|
// End:
|
||||||
|
|