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Diffstat (limited to '3rdparty/SDL2/Xcode-iOS/Demos/src/fireworks.c')
-rw-r--r--3rdparty/SDL2/Xcode-iOS/Demos/src/fireworks.c71
1 files changed, 35 insertions, 36 deletions
diff --git a/3rdparty/SDL2/Xcode-iOS/Demos/src/fireworks.c b/3rdparty/SDL2/Xcode-iOS/Demos/src/fireworks.c
index a5beada9136..dbbd738113c 100644
--- a/3rdparty/SDL2/Xcode-iOS/Demos/src/fireworks.c
+++ b/3rdparty/SDL2/Xcode-iOS/Demos/src/fireworks.c
@@ -10,13 +10,13 @@
#include <math.h>
#include <time.h>
-#define MILLESECONDS_PER_FRAME 16 /* about 60 frames per second */
#define ACCEL 0.0001f /* acceleration due to gravity, units in pixels per millesecond squared */
#define WIND_RESISTANCE 0.00005f /* acceleration per unit velocity due to wind resistance */
#define MAX_PARTICLES 2000 /* maximum number of particles displayed at once */
static GLuint particleTextureID; /* OpenGL particle texture id */
static SDL_bool pointSizeExtensionSupported; /* is GL_OES_point_size_array supported ? */
+static float pointSizeScale;
/*
used to describe what type of particle a given struct particle is.
emitter - this particle flies up, shooting off trail particles, then finally explodes into dust particles.
@@ -55,7 +55,7 @@ void initializeParticles(void);
void initializeTexture();
int nextPowerOfTwo(int x);
void drawParticles();
-void stepParticles(void);
+void stepParticles(double deltaTime);
/* helper function (used in texture loading)
returns next power of two greater than or equal to x
@@ -71,11 +71,12 @@ nextPowerOfTwo(int x)
}
/*
- steps each active particle by timestep MILLESECONDS_PER_FRAME
+ steps each active particle by timestep deltaTime
*/
void
-stepParticles(void)
+stepParticles(double deltaTime)
{
+ float deltaMilliseconds = deltaTime * 1000;
int i;
struct particle *slot = particles;
struct particle *curr = particles;
@@ -93,10 +94,10 @@ stepParticles(void)
curr->isActive = 0;
/* step velocity, then step position */
- curr->yvel += ACCEL * MILLESECONDS_PER_FRAME;
+ curr->yvel += ACCEL * deltaMilliseconds;
curr->xvel += 0.0f;
- curr->y += curr->yvel * MILLESECONDS_PER_FRAME;
- curr->x += curr->xvel * MILLESECONDS_PER_FRAME;
+ curr->y += curr->yvel * deltaMilliseconds;
+ curr->x += curr->xvel * deltaMilliseconds;
/* particle behavior */
if (curr->type == emitter) {
@@ -111,29 +112,29 @@ stepParticles(void)
sqrt(curr->xvel * curr->xvel + curr->yvel * curr->yvel);
/* if wind resistance is not powerful enough to stop us completely,
then apply winde resistance, otherwise just stop us completely */
- if (WIND_RESISTANCE * MILLESECONDS_PER_FRAME < speed) {
+ if (WIND_RESISTANCE * deltaMilliseconds < speed) {
float normx = curr->xvel / speed;
float normy = curr->yvel / speed;
curr->xvel -=
- normx * WIND_RESISTANCE * MILLESECONDS_PER_FRAME;
+ normx * WIND_RESISTANCE * deltaMilliseconds;
curr->yvel -=
- normy * WIND_RESISTANCE * MILLESECONDS_PER_FRAME;
+ normy * WIND_RESISTANCE * deltaMilliseconds;
} else {
curr->xvel = curr->yvel = 0; /* stop particle */
}
- if (curr->color[3] <= MILLESECONDS_PER_FRAME * 0.1275f) {
+ if (curr->color[3] <= deltaMilliseconds * 0.1275f) {
/* if this next step will cause us to fade out completely
then just mark for deletion */
curr->isActive = 0;
} else {
/* otherwise, let's fade a bit more */
- curr->color[3] -= MILLESECONDS_PER_FRAME * 0.1275f;
+ curr->color[3] -= deltaMilliseconds * 0.1275f;
}
/* if we're a dust particle, shrink our size */
if (curr->type == dust)
- curr->size -= MILLESECONDS_PER_FRAME * 0.010f;
+ curr->size -= deltaMilliseconds * 0.010f;
}
@@ -147,7 +148,7 @@ stepParticles(void)
/* the number of active particles is computed as the difference between
old number of active particles, where slot points, and the
new size of the array, where particles points */
- num_active_particles = slot - particles;
+ num_active_particles = (int) (slot - particles);
}
/*
@@ -206,7 +207,7 @@ explodeEmitter(struct particle *emitter)
p->y = emitter->y + emitter->yvel;
p->isActive = 1;
p->type = dust;
- p->size = 15;
+ p->size = 15 * pointSizeScale;
/* inherit emitter's color */
p->color[0] = emitter->color[0];
p->color[1] = emitter->color[1];
@@ -244,7 +245,7 @@ spawnTrailFromEmitter(struct particle *emitter)
p->color[3] = (0.7f) * 255;
/* set other attributes */
- p->size = 10;
+ p->size = 10 * pointSizeScale;
p->type = trail;
p->isActive = 1;
@@ -298,7 +299,7 @@ spawnEmitterParticle(GLfloat x, GLfloat y)
p->xvel = 0;
p->yvel = -sqrt(2 * ACCEL * (screen_h - y));
/* set other attributes */
- p->size = 10;
+ p->size = 10 * pointSizeScale;
p->type = emitter;
p->isActive = 1;
/* our array has expanded at the end */
@@ -363,7 +364,7 @@ main(int argc, char *argv[])
{
SDL_Window *window; /* main window */
SDL_GLContext context;
- int w, h;
+ int drawableW, drawableH;
Uint32 startFrame; /* time frame began to process */
Uint32 endFrame; /* time frame ended processing */
Uint32 delay; /* time to pause waiting to draw next frame */
@@ -391,11 +392,19 @@ main(int argc, char *argv[])
SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 1);
/* create main window and renderer */
- window = SDL_CreateWindow(NULL, 0, 0, SCREEN_WIDTH, SCREEN_HEIGHT,
- SDL_WINDOW_OPENGL |
- SDL_WINDOW_BORDERLESS);
+ window = SDL_CreateWindow(NULL, 0, 0, 320, 480,
+ SDL_WINDOW_OPENGL | SDL_WINDOW_BORDERLESS | SDL_WINDOW_ALLOW_HIGHDPI);
context = SDL_GL_CreateContext(window);
+ /* The window size and drawable size may be different when highdpi is enabled,
+ * due to the increased pixel density of the drawable. */
+ SDL_GetWindowSize(window, &screen_w, &screen_h);
+ SDL_GL_GetDrawableSize(window, &drawableW, &drawableH);
+
+ /* In OpenGL, point sizes are always in pixels. We don't want them looking
+ * tiny on a retina screen. */
+ pointSizeScale = (float) drawableH / (float) screen_h;
+
/* load the particle texture */
initializeTexture();
@@ -412,8 +421,7 @@ main(int argc, char *argv[])
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
- SDL_GetWindowSize(window, &screen_w, &screen_h);
- glViewport(0, 0, screen_w, screen_h);
+ glViewport(0, 0, drawableW, drawableH);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
@@ -436,14 +444,14 @@ main(int argc, char *argv[])
glEnableClientState(GL_POINT_SIZE_ARRAY_OES);
} else {
/* if extension not available then all particles have size 10 */
- glPointSize(10);
+ glPointSize(10 * pointSizeScale);
}
done = 0;
/* enter main loop */
while (!done) {
- startFrame = SDL_GetTicks();
SDL_Event event;
+ double deltaTime = updateDeltaTime();
while (SDL_PollEvent(&event)) {
if (event.type == SDL_QUIT) {
done = 1;
@@ -454,19 +462,10 @@ main(int argc, char *argv[])
spawnEmitterParticle(x, y);
}
}
- stepParticles();
+ stepParticles(deltaTime);
drawParticles();
SDL_GL_SwapWindow(window);
- endFrame = SDL_GetTicks();
-
- /* figure out how much time we have left, and then sleep */
- delay = MILLESECONDS_PER_FRAME - (endFrame - startFrame);
- if (delay > MILLESECONDS_PER_FRAME) {
- delay = MILLESECONDS_PER_FRAME;
- }
- if (delay > 0) {
- SDL_Delay(delay);
- }
+ SDL_Delay(1);
}
/* delete textures */