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render.c
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render.c
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#include "render.h"
#include <math.h>
#include <stdio.h>
#include <SDL2/SDL.h>
#include <SDL2/SDL_ttf.h>
#include "universe.h"
void renderHUD(struct renderstate *render, struct simulation *sim,
struct universe *univ);
void renderHotParticle(struct renderstate *render, struct simulation *sim,
struct universe *univ);
void renderText(struct renderstate *render, TTF_Font * font,
const char *text, int x, int y, int flags, SDL_Color colour);
void renderCircle(struct renderstate *render, int centerX, int centerY,
double radius);
struct renderstate *renderstateInit(const char *title, int width, int height)
{
// int i;
struct renderstate *render =
(struct renderstate *)malloc(sizeof(struct renderstate));
memset(render, 0, sizeof(struct renderstate));
if (SDL_Init(SDL_INIT_EVERYTHING)) {
return 0;
}
if (TTF_Init() == -1) {
return 0;
}
if (SDL_CreateWindowAndRenderer
(width, height,
SDL_WINDOW_RESIZABLE | SDL_WINDOW_OPENGL | SDL_WINDOW_SHOWN,
&render->window, &render->renderer) != 0) {
return 0;
}
SDL_SetWindowTitle(render->window, title);
SDL_GL_SetSwapInterval(1);
render->font_small = TTF_OpenFont("font.ttf", 8);
render->font_large = TTF_OpenFont("font.ttf", 12);
if (render->font_small == 0 || render->font_large == 0) {
return 0;
}
render->points =
(SDL_Point *) malloc(sizeof(SDL_Point) * width * height);
render->scale = 1.0f;
render->xPos = 0;
render->yPos = 0;
render->width = width;
render->height = height;
render->frames = 0;
render->fps = 0;
render->last_frame = SDL_GetTicks();
return render;
}
struct renderstate *renderstateInitFromFile(FILE * file)
{
char *line = 0;
size_t lineLength = 0;
char *title = 0;
size_t titleLength = 0;
int width, height;
struct renderstate *render;
// get title
if (readFileLine(&title, &titleLength, file) == -1) {
free(line);
free(title);
return 0;
}
// get width/height
if (readFileLine(&line, &lineLength, file) == -1) {
free(line);
free(title);
return 0;
}
if (sscanf(line, "%d %d", &width, &height) != 2) {
free(line);
free(title);
return 0;
}
// init the render so far
if (!(render = renderstateInit(title, width, height))) {
free(line);
free(title);
return render;
}
// get scale
if (readFileLine(&line, &lineLength, file) == -1) {
freeRenderstate(render);
free(line);
free(title);
return 0;
}
if (sscanf(line, "%f", &render->scale) != 1) {
freeRenderstate(render);
free(line);
free(title);
return 0;
}
// get x/y pos
if (readFileLine(&line, &lineLength, file) == -1) {
freeRenderstate(render);
free(line);
free(title);
return 0;
}
if (sscanf(line, "%lf %lf", &render->xPos, &render->yPos) != 2) {
freeRenderstate(render);
free(line);
free(title);
return 0;
}
free(line);
free(title);
return render;
}
void renderUniverse(struct renderstate *render, struct simulation *sim,
struct universe *univ)
{
// SDL_Rect rect;
int i;
int rb, g;
double maxCharge = 0;
for (i = 0; i < univ->nextParticle; i++) {
if (univ->particles[i].isActive
&& fabs(univ->particles[i].charge) > maxCharge) {
maxCharge = fabs(univ->particles[i].charge);
}
}
SDL_SetRenderDrawColor(render->renderer, 0, 0, 0, 255);
SDL_RenderClear(render->renderer);
// FPS
render->frames++;
if ((SDL_GetTicks() - render->last_frame) > 1000) {
render->fps = render->frames;
render->frames = 0;
render->last_frame += 1000;
}
// render->point_count = 0;
for (i = 0; i < univ->nextParticle; i++) {
if (!univ->particles[i].isActive) {
continue;
}
double x =
(((univ->particles[i].xPos * univ->scale) +
render->xPos) * render->scale) + (render->width / 2);
double y =
(((univ->particles[i].yPos * univ->scale) +
render->yPos) * render->scale) + (render->height / 2);
double size =
(int)(univ->particles[i].size * render->scale *
univ->scale);
if (size < 1) {
size = 1;
}
if (univ->particles[i].charge == 0) {
g = 255;
rb = 0;
} else if (fabs(univ->particles[i].charge) < maxCharge / 2.0) {
g = 255;
rb = (int)(255.0 *
(fabs(univ->particles[i].charge) /
(maxCharge / 2.0)));
} else {
rb = 255;
g = (int)(255.0 *
((maxCharge -
fabs(univ->particles[i].charge)) /
(maxCharge / 2.0)));
}
if (univ->particles[i].charge < 0) {
SDL_SetRenderDrawColor(render->renderer, 0, g, rb, 255);
renderCircle(render, x, y, size);
} else {
SDL_SetRenderDrawColor(render->renderer, rb, g, 0, 255);
renderCircle(render, x, y, size);
}
// SDL_RenderFillRect(render->renderer, &rect);
}
// SDL_RenderDrawPoints(render->renderer, render->points,
// render->point_count);
renderHotParticle(render, sim, univ);
renderHUD(render, sim, univ);
SDL_RenderPresent(render->renderer);
}
void renderHUD(struct renderstate *render, struct simulation *sim,
struct universe *univ)
{
float pixelsPerMeter = univ->scale * render->scale;
int scale_size = 100;
char text[256];
SDL_Color text_colour = { 255, 255, 255, 255 };
SDL_SetRenderDrawColor(render->renderer, 255, 255, 255, 255);
// Draw the scale in the bottom right corner
SDL_RenderDrawLine(render->renderer, render->width - 10,
render->height - 10, render->width - 10,
render->height - 20);
SDL_RenderDrawLine(render->renderer, render->width - 10,
render->height - 15, render->width - 10 - scale_size,
render->height - 15);
SDL_RenderDrawLine(render->renderer, render->width - 10 - scale_size,
render->height - 10, render->width - 10 - scale_size,
render->height - 20);
sprintf(text, "%.2fm", (1 / pixelsPerMeter) * scale_size);
renderText(render, render->font_small, text,
render->width - 10 - (scale_size / 2), render->height - 25,
FONT_CENTER, text_colour);
// Fidelity
sprintf(text, "%dx", univ->fidelity);
renderText(render, render->font_small, text, 10, 30, FONT_LEFT,
text_colour);
// Draw the seconds/second
sprintf(text, "%.2fs/s", render->fps * univ->speed);
renderText(render, render->font_small, text,
10, 45, FONT_LEFT, text_colour);
// Draw the FPS
sprintf(text, "%d frame/s", render->fps);
renderText(render, render->font_small, text, 10, 60, FONT_LEFT,
text_colour);
// Draw the pause symbol
if (sim->paused) {
SDL_Rect rect;
SDL_SetRenderDrawColor(render->renderer, 255, 0, 0, 255);
rect.x = 10;
rect.y = 10;
rect.w = 6;
rect.h = 16;
SDL_RenderFillRect(render->renderer, &rect);
rect.x = 20;
SDL_RenderFillRect(render->renderer, &rect);
}
// Draw the saving text
if (sim->savingTime > -1) {
sim->savingTime--;
strcpy(text, "Saving...");
renderText(render, render->font_large, text, render->width / 2,
render->height / 2, FONT_CENTER, text_colour);
}
}
void renderHotParticle(struct renderstate *render, struct simulation *sim,
struct universe *univ)
{
struct particle p;
SDL_Color text_selected = { 255, 255, 0, 255 };
SDL_Color text_unselected = { 255, 255, 255, 255 };
char text[256];
if (sim->hotParticle == -1) {
return;
}
p = univ->particles[sim->hotParticle];
double x =
(((p.xPos * univ->scale) + render->xPos) * render->scale) +
(render->width / 2);
double y =
(((p.yPos * univ->scale) + render->yPos) * render->scale) +
(render->height / 2);
double size = p.size * 2 * render->scale * univ->scale;
// Draw X on the hot particle
SDL_SetRenderDrawColor(render->renderer, 0, 0, 0, 255);
SDL_RenderDrawLine(render->renderer, x - (size / 4), y - (size / 4),
x + (size / 4), y + (size / 4));
SDL_RenderDrawLine(render->renderer, x + (size / 4), y - (size / 4),
x - (size / 4), y + (size / 4));
// Draw velocity
double distance = sqrt(pow(p.xVel, 2) + pow(p.yVel, 2));
double scale = 10 * render->scale * univ->scale;
SDL_SetRenderDrawColor(render->renderer, 0, 255, 0, 255);
SDL_RenderDrawLine(render->renderer, x, y, x + (p.xVel * scale),
y + (p.yVel * scale));
sprintf(text, "%f m/s", distance);
renderText(render, render->font_small, text, x + (p.xVel * scale),
y + (p.yVel * scale), FONT_LEFT, text_unselected);
// Draw the options and current one.
renderText(render, render->font_large, "Velocity", x,
y + (size / 2) + 10, FONT_LEFT,
sim->hotParticleState ==
HOTPARTICLE_VELOCITY ? text_selected : text_unselected);
sprintf(text, "Mass: %.2fkg", p.mass);
renderText(render, render->font_large, text, x, y + (size / 2) + 25,
FONT_LEFT,
sim->hotParticleState ==
HOTPARTICLE_MASS ? text_selected : text_unselected);
sprintf(text, "Charge: %.7fC", p.charge);
renderText(render, render->font_large, text, x, y + (size / 2) + 40,
FONT_LEFT,
sim->hotParticleState ==
HOTPARTICLE_CHARGE ? text_selected : text_unselected);
}
void renderText(struct renderstate *render, TTF_Font * font, const char *text,
int x, int y, int flags, SDL_Color colour)
{
SDL_Surface *text_surface;
SDL_Texture *text_texture;
SDL_Rect text_position;
text_surface = TTF_RenderText_Blended(font, text, colour);
text_position.x = x;
text_position.y = y;
text_position.w = text_surface->w;
text_position.h = text_surface->h;
if (flags == FONT_CENTER) {
text_position.x -= (text_surface->w / 2);
text_position.y -= (text_surface->h / 2);
} else if (flags == FONT_RIGHT) {
text_position.x -= text_surface->w;
}
text_texture = SDL_CreateTextureFromSurface(render->renderer,
text_surface);
SDL_RenderCopy(render->renderer, text_texture, 0, &text_position);
SDL_DestroyTexture(text_texture);
SDL_FreeSurface(text_surface);
}
void renderCircle(struct renderstate *render, int centerX, int centerY,
double radius)
{
#define MIN(a, b) ((a) < (b) ? (a) : (b))
#define MAX(a, b) ((a) > (b) ? (a) : (b))
int left, right, top, bottom;
int x, y;
int point_count = 0;
double radius_squared = pow(radius, 2);
top = MAX(0, centerY - radius);
bottom = MIN(render->height, centerY + radius);
left = MAX(0, centerX - radius);
right = MIN(render->width, centerX + radius);
for (x = left; x < right; x++) {
for (y = top; y < bottom; y++) {
if ((pow(centerX - x, 2) + pow(centerY - y, 2)) <=
radius_squared) {
render->points[point_count].x = x;
render->points[point_count].y = y;
point_count++;
// SDL_RenderDrawPoint(render->renderer, x, y);
}
}
}
SDL_RenderDrawPoints(render->renderer, render->points, point_count);
}
void renderstateToFile(struct renderstate *render, FILE * file)
{
fprintf(file, "Saved universe\n");
fprintf(file, "%d %d\n", render->width, render->height);
fprintf(file, "%lf\n", render->scale);
fprintf(file, "%lf %lf\n", render->xPos, render->yPos);
}
void freeRenderstate(struct renderstate *render)
{
// Cleanup variables
free(render->points);
// Cleanup fonts
TTF_CloseFont(render->font_small);
TTF_CloseFont(render->font_large);
// Cleanup SDL
SDL_DestroyWindow(render->window);
SDL_DestroyRenderer(render->renderer);
SDL_Quit();
free(render);
}