void renderRectBorder(SDL_Renderer* renderer, Coordinate a, Coordinate b, SDL_Color color) {
SDL_Rect drawRect;
drawRect.x = a.x;
drawRect.y = a.y;
drawRect.w = b.x-a.x;
drawRect.h = b.y-a.y;
SetRenderDrawColor(renderer, color);
SDL_RenderDrawRect(renderer, &drawRect);
}
bool init() {
bool success = true;
// Initialize SDL
if ( SDL_Init(SDL_INIT_VIDEO) < 0 )
{
printf("SDL could not initialize! SDL_Error: %s\n", SDL_GetError());
success = false;
} else {
// Create window
/* Signature: (window caption, window x position,
window y position, window width, window height,
window is visible)
*/
gWindow = SDL_CreateWindow("Hello World", SDL_WINDOWPOS_UNDEFINED,
SDL_WINDOWPOS_UNDEFINED, SCREEN_WIDTH, SCREEN_HEIGHT,
SDL_WINDOW_SHOWN);
if (gWindow == NULL) {
printf("SDL window could not be created! SDL_Error: %s\n", SDL_GetError());
success = false;
} else {
// Create a renderer for window
/* Signature:
(Window, index of rendering driver or first one supporting flags [-1], requirement flags)
*/
gRenderer = SDL_CreateRenderer(gWindow, -1, SDL_RENDERER_ACCELERATED);
if (gRenderer == NULL)
{
printf("Renderer could not be created! SDL Error: %s\n", SDL_GetError());
success = false;
}
else {
// Initialize renderer color
/* Draw color to rendering context, r(ed), g(reen), b(lue), a(lpha) */
SetRenderDrawColor(gRenderer, BASE03);
// Initialize PNG loading (separate SDL2 library)
int imgFlags = IMG_INIT_PNG;
if ( !(IMG_Init(imgFlags) & imgFlags )) {
printf("SDL_image could not be initialized! SDL_Error: %s\n", IMG_GetError());
success = false;
} else {
// Get window surface
gScreenSurface = SDL_GetWindowSurface(gWindow);
}
}
}
}
return success;
}
void renderEllipse(SDL_Renderer* renderer, Coordinate center, int a, int b, SDL_Color color) {
SetRenderDrawColor(renderer, color);
int xc = center.x;
int yc = center.y;
int a2 = a * a;
int b2 = b * b;
int twoa2 = 2 * a2;
int twob2 = 2 * b2;
int p;
int x = 0;
int y = b;
int px = 0;
int py = twoa2 * y;
/* Plot the initial point in each quadrant. */
ellipsePlotPoints(renderer, xc, yc, x, y);
/* Region 1 */
p = std::round (b2 - (a2 * b) + (0.25 * a2));
while (px < py) {
x++;
px += twob2;
if (p < 0)
p += b2 + px;
else {
y--;
py -= twoa2;
p += b2 + px - py;
}
ellipsePlotPoints(renderer, xc, yc, x, y);
}
/* Region 2 */
p = std::round (b2 * (x+0.5) * (x+0.5) + a2 * (y-1) * (y-1) - a2 * b2);
while (y > 0) {
y--;
py -= twoa2;
if (p > 0)
p += a2 - py;
else {
x++;
px += twob2;
p += a2 - py + px;
}
ellipsePlotPoints(renderer, xc, yc, x, y);
}
}
void renderLine(SDL_Renderer* renderer, Coordinate a, Coordinate b, SDL_Color color) {
SetRenderDrawColor(renderer, color);
SDL_RenderDrawLine(renderer, a.x, a.y, b.x, b.y);
}
// SDL REQUIRES this signature for main
int main(int argc, char* args[]) {
// Main Loop flag
bool quit = false;
int render = 0;
// Event handler
SDL_Event e;
//Start up SDL and create window
if( !init() )
{
printf("Failed to initialize!\n");
return 1;
}
else
{
//Load media
if( !loadMedia() )
{
printf("Failed to load media!\n");
return 1;
}
}
gTexture = gKeyPressTextures[KEY_PRESS_SURFACE_DEFAULT];
SDL_Rect lowerViewport;
lowerViewport.x = 0;
lowerViewport.y = SCREEN_HEIGHT / 2;
lowerViewport.w = SCREEN_WIDTH ;
lowerViewport.h = SCREEN_HEIGHT / 2;
SDL_Rect topViewport;
topViewport.x = 0;
topViewport.y = 0;
topViewport.w = SCREEN_WIDTH;
topViewport.h = SCREEN_HEIGHT / 2;
SDL_Rect fullViewport;
fullViewport.x = 0;
fullViewport.y = 0;
fullViewport.w = SCREEN_WIDTH;
fullViewport.h = SCREEN_HEIGHT;
// While application is running
while (!quit) {
// Handle events on queue
while (SDL_PollEvent(&e) != 0) {
// User requests quit
if (e.type == SDL_QUIT || e.key.keysym.sym == SDLK_ESCAPE) {
quit = true;
}
// User presses a key
else if (e.type == SDL_KEYDOWN)
{
switch(e.key.keysym.sym)
{
default:
render = RENDER_NULL;
break;
case SDLK_h:
gTexture = gKeyPressTextures[KEY_PRESS_SURFACE_LEFT];
render = RENDER_SHAPE;
break;
case SDLK_j:
gTexture = gKeyPressTextures[KEY_PRESS_SURFACE_DOWN];
render = RENDER_SHAPE;
break;
case SDLK_k:
gTexture = gKeyPressTextures[KEY_PRESS_SURFACE_UP];
render = RENDER_SHAPE;
break;
case SDLK_l:
gTexture = gKeyPressTextures[KEY_PRESS_SURFACE_RIGHT];
render = RENDER_SHAPE;
break;
case SDLK_SPACE:
gTexture = gKeyPressTextures[KEY_PRESS_SURFACE_SPACE];
render = RENDER_SHAPE;
break;
case SDLK_c:
render = RENDER_CIRCLE;
}
}
} // while (SDL_PolLEvent(&e) != 0
if (render != RENDER_NULL) {
// Clear screen
SDL_RenderClear(gRenderer);
switch(render)
{
case RENDER_CIRCLE:
// Render image of circle via LTexture
SDL_RenderSetViewport(gRenderer, &fullViewport);
gBackgroundTexture.render(0, 0);
gCircleTexture.render(240, 190);
break;
case RENDER_SHAPE:
// Render image to screen via texture set previously
SDL_RenderSetViewport(gRenderer, &topViewport);
SDL_RenderCopy(gRenderer, gTexture, NULL, NULL);
SDL_RenderSetViewport(gRenderer, &lowerViewport);
//Render red filled quad
SDL_Rect fillRect = {SCREEN_WIDTH / 4, SCREEN_HEIGHT / 4, SCREEN_WIDTH / 2, SCREEN_HEIGHT / 2};
SetRenderDrawColor(gRenderer, BASE01);
SDL_RenderFillRect( gRenderer, &fillRect );
// Draw a rectanglular outline with empty center
SDL_Rect outlineRect = {SCREEN_WIDTH / 6, SCREEN_HEIGHT / 6, SCREEN_WIDTH * 2 / 3, SCREEN_HEIGHT * 2 / 3 };
SetRenderDrawColor(gRenderer, BASE03);
SDL_RenderDrawRect(gRenderer, &outlineRect);
// Draw a thin pixel line
SetRenderDrawColor(gRenderer, BLUE);
SDL_RenderDrawLine(gRenderer, 0, SCREEN_HEIGHT / 2, SCREEN_WIDTH, SCREEN_HEIGHT / 2);
// Draw vertical line of cyan dots
SetRenderDrawColor(gRenderer, CYAN);
for (int i = 0; i < SCREEN_HEIGHT; i += 4) {
SDL_RenderDrawPoint(gRenderer, SCREEN_WIDTH / 2, i);
}
SetRenderDrawColor(gRenderer, BASE03);
break;
} // render switch
// Update screen
SDL_RenderPresent(gRenderer);
} // if render != null
} // while (!quit)
// Free up resources and close SDL
close();
return 0;
}