Added acceleration to make it feel better to use.

This commit is contained in:
Barra Ó Catháin 2023-03-15 23:22:16 +00:00
parent 9344fc9cd8
commit 53a88025cd
2 changed files with 118 additions and 28 deletions

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@ -1,7 +1,6 @@
// SDL Experiment 02, Barra Ó Catháin.
// SDL Experiment 03, Barra Ó Catháin.
// ===================================
#include <SDL2/SDL.h>
#include <SDL2/SDL_image.h>
#include <SDL2/SDL_timer.h>
#include <stdbool.h>
#include <stdint.h>
@ -55,8 +54,10 @@ int main(int argc, char ** argv)
{
SDL_Event event;
bool quit = false;
int width = 0, height = 0, positionX = 0, positionY = 0, velocityX = 0, velocityY = 0;
int width = 0, height = 0;
uint32_t rendererFlags = SDL_RENDERER_ACCELERATED;
long positionX = 320, positionY = 320, velocityX = 0, velocityY = 0;
bool accelLeft = false, accelRight = false, accelUp = false, accelDown = false;
// Initialize the SDL library, video, sound, and input:
if (SDL_Init(SDL_INIT_EVERYTHING) != 0)
@ -64,18 +65,10 @@ int main(int argc, char ** argv)
printf("SDL Initialization Error: %s\n", SDL_GetError());
}
IMG_Init(IMG_INIT_PNG);
// Create an SDL window and rendering context in that window:
SDL_Window * window = SDL_CreateWindow("SDL_TEST", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, 640, 640, 0);
SDL_Renderer * renderer = SDL_CreateRenderer(window, -1, rendererFlags);
SDL_Texture * targetTexture;
targetTexture = IMG_LoadTexture(renderer, "./02-TGT.png");
SDL_Rect targetText;
targetText.w = 16;
targetText.h = 8;
// Enable resizing the window:
SDL_SetWindowResizable(window, SDL_TRUE);
@ -91,28 +84,61 @@ int main(int argc, char ** argv)
quit = true;
break;
}
// Begin accelerating in the direction that is pressed:
case SDL_KEYDOWN:
{
switch (event.key.keysym.sym)
{
case SDLK_LEFT:
{
velocityX += -1;
accelLeft = true;
break;
}
case SDLK_RIGHT:
{
velocityX += 1;
accelRight = true;
break;
}
case SDLK_UP:
{
velocityY += -1;
accelUp = true;
break;
}
case SDLK_DOWN:
{
velocityY += 1;
accelDown = true;
break;
}
default:
{
break;
}
}
break;
}
// Stop accelerating in the direction that is released:
case SDL_KEYUP:
{
switch (event.key.keysym.sym)
{
case SDLK_LEFT:
{
accelLeft = false;
break;
}
case SDLK_RIGHT:
{
accelRight = false;
break;
}
case SDLK_UP:
{
accelUp = false;
break;
}
case SDLK_DOWN:
{
accelDown = false;
break;
}
default:
@ -129,9 +155,81 @@ int main(int argc, char ** argv)
}
}
// Accelerate:
if(accelLeft)
{
velocityX -= 2;
}
if(accelRight)
{
velocityX += 2;
}
if(accelUp)
{
velocityY -= 2;
}
if(accelDown)
{
velocityY += 2;
}
// Limit velocity:
if(velocityX > 10)
{
velocityX = 10;
}
if(velocityY > 10)
{
velocityY = 10;
}
if(velocityX < -10)
{
velocityX = -10;
}
if(velocityY < -10)
{
velocityY = -10;
}
// Deccelerate:
if(velocityX != 0)
{
velocityX = (velocityX < 0) ? velocityX + 1 : velocityX - 1;
}
if(velocityY != 0)
{
velocityY = (velocityY < 0) ? velocityY + 1 : velocityY - 1;
}
// Move the position:
positionX += velocityX;
positionY += velocityY;
if(velocityX != 0)
{
positionX += velocityX;
if(positionX < 0)
{
positionX = 0;
}
if(positionX > 640)
{
positionX = 640;
}
}
if(velocityY != 0)
{
positionY += velocityY;
if(positionY < 0)
{
positionY = 0;
}
if(positionY > 640)
{
positionY = 640;
}
}
// Store the window's current width and height:
SDL_GetWindowSize(window, &width, &height);
@ -151,23 +249,15 @@ int main(int argc, char ** argv)
// Draw a circle around the position pointer:
DrawCircle(renderer, positionX, positionY, 15);
// Set the rect at the correct position to put the TGT down:
targetText.x = positionX + 20;
targetText.y = positionY - 4;
if(positionX < width/2)
{
targetText.x = positionX - 36;
}
SDL_RenderCopy(renderer, targetTexture, NULL, &targetText);
// Present the rendered graphics:
SDL_RenderPresent(renderer);
// Delay enough so that we run at 144 frames:
SDL_Delay(1000 / 144);
SDL_Delay(1000 / 60);
}
return 0;
}
// ===========================================================================================
// Local Variables:
// compile-command: "gcc `sdl2-config --libs --cflags` SDL2-Experiment-02.c -lSDL2_image -lm"
// compile-command: "gcc `sdl2-config --libs --cflags` SDL2-Experiment-03.c -lm"
// End: