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small3dlib/programs/city.c
2022-04-16 22:58:49 +02:00

337 lines
8.2 KiB
C

/*
Example program for small3dlib -- a GTA-like game demo.
author: Miloslav Ciz
license: CC0 1.0
*/
#include <SDL2/SDL.h>
#include <stdio.h>
#include <time.h>
#define S3L_FLAT 0
#define S3L_NEAR_CROSS_STRATEGY 3
#define S3L_PERSPECTIVE_CORRECTION 2
#define S3L_SORT 0
#define S3L_STENCIL_BUFFER 0
#define S3L_Z_BUFFER 2
#define S3L_PIXEL_FUNCTION drawPixel
#define S3L_RESOLUTION_X 640
#define S3L_RESOLUTION_Y 480
#include "../small3dlib.h"
#include "cityModel.h"
#include "cityTexture.h"
#include "carModel.h"
#define TEXTURE_W 256
#define TEXTURE_H 256
#define MAX_VELOCITY 1000
#define ACCELERATION 700
#define TURN_SPEED 300
#define FRICTION 600
S3L_Model3D models[2];
const uint8_t collisionMap[8 * 10] =
{
1,1,1,1,1,1,1,1,
1,1,1,1,0,0,0,1,
1,1,1,1,0,1,0,1,
2,2,1,0,0,0,0,3,
1,2,1,0,1,1,3,1,
2,0,0,0,1,1,3,3,
1,0,1,0,0,1,1,1,
1,0,0,0,1,1,1,1,
1,1,1,1,1,1,1,1,
1,1,1,1,1,1,1,1
};
S3L_Scene scene;
uint32_t pixels[S3L_RESOLUTION_X * S3L_RESOLUTION_Y];
uint32_t frame = 0;
void clearScreen()
{
uint32_t index = 0;
for (uint16_t y = 0; y < S3L_RESOLUTION_Y; ++y)
{
S3L_Unit t = S3L_min(S3L_FRACTIONS_PER_UNIT,((y * S3L_FRACTIONS_PER_UNIT) / S3L_RESOLUTION_Y) * 4);
uint32_t r = S3L_interpolateByUnit(200,242,t);
uint32_t g = S3L_interpolateByUnit(102,255,t);
uint32_t b = S3L_interpolateByUnit(255,230,t);
uint32_t color = (r << 24) | (g << 16 ) | (b << 8);
for (uint16_t x = 0; x < S3L_RESOLUTION_X; ++x)
{
pixels[index] = color;
index++;
}
}
}
static inline void setPixel(int x, int y, uint8_t red, uint8_t green, uint8_t blue)
{
uint8_t *p = ((uint8_t *) pixels) + (y * S3L_RESOLUTION_X + x) * 4 + 1;
*p = blue;
++p;
*p = green;
++p;
*p = red;
}
void sampleTexture(int32_t u, int32_t v, uint8_t *r, uint8_t *g, uint8_t *b)
{
u = S3L_clamp(u,0,CITY_TEXTURE_WIDTH - 1);
v = S3L_clamp(v,0,CITY_TEXTURE_HEIGHT - 1);
const uint8_t *t = cityTexture + (v * CITY_TEXTURE_WIDTH + u) * 3;
*r = *t;
t++;
*g = *t;
t++;
*b = *t;
}
uint32_t previousTriangle = -1;
S3L_Vec4 uv0, uv1, uv2;
void drawPixel(S3L_PixelInfo *p)
{
if (p->triangleID != previousTriangle)
{
const S3L_Index *uvIndices;
const S3L_Unit *uvs;
if (p->modelIndex == 0)
{
uvIndices = cityUVIndices;
uvs = cityUVs;
}
else
{
uvIndices = carUVIndices;
uvs = carUVs;
}
S3L_getIndexedTriangleValues(p->triangleIndex,uvIndices,uvs,2,&uv0,&uv1,&uv2);
previousTriangle = p->triangleID;
}
uint8_t r, g, b;
S3L_Unit uv[2];
uv[0] = S3L_interpolateBarycentric(uv0.x,uv1.x,uv2.x,p->barycentric);
uv[1] = S3L_interpolateBarycentric(uv0.y,uv1.y,uv2.y,p->barycentric);
sampleTexture(uv[0] >> 1,uv[1] >> 1,&r,&g,&b);
setPixel(p->x,p->y,r,g,b);
}
void draw()
{
S3L_newFrame();
clearScreen();
S3L_drawScene(scene);
}
static inline uint8_t collision(S3L_Vec4 worldPosition)
{
worldPosition.x /= S3L_FRACTIONS_PER_UNIT;
worldPosition.z /= -S3L_FRACTIONS_PER_UNIT;
uint16_t index = worldPosition.z * 8 + worldPosition.x;
return collisionMap[index];
}
static inline void handleCollision(S3L_Vec4 *pos, S3L_Vec4 previousPos)
{
S3L_Vec4 newPos = *pos;
newPos.x = previousPos.x;
if (collision(newPos))
{
newPos = *pos;
newPos.z = previousPos.z;
if (collision(newPos))
newPos = previousPos;
}
*pos = newPos;
}
int16_t fps = 0;
int main()
{
SDL_Window *window = SDL_CreateWindow("city demo", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, S3L_RESOLUTION_X, S3L_RESOLUTION_Y, SDL_WINDOW_SHOWN);
SDL_Renderer *renderer = SDL_CreateRenderer(window,-1,0);
SDL_Texture *textureSDL = SDL_CreateTexture(renderer,SDL_PIXELFORMAT_RGBX8888, SDL_TEXTUREACCESS_STATIC, S3L_RESOLUTION_X, S3L_RESOLUTION_Y);
SDL_Surface *screenSurface = SDL_GetWindowSurface(window);
SDL_Event event;
cityModelInit();
carModelInit();
models[0] = cityModel;
models[1] = carModel;
S3L_sceneInit(models,2,&scene);
S3L_transform3DSet(1909,16,-3317,0,-510,0,512,512,512,&(models[1].transform));
int running = 1;
clock_t nextPrintT;
nextPrintT = clock();
S3L_Vec4 carDirection;
S3L_vec4Init(&carDirection);
scene.camera.transform.translation.y = S3L_FRACTIONS_PER_UNIT / 2;
scene.camera.transform.rotation.x = -S3L_FRACTIONS_PER_UNIT / 16;
int16_t velocity = 0;
while (running) // main loop
{
clock_t frameStartT = clock();
models[1].transform.rotation.y += models[1].transform.rotation.z; // overturn the car for the rendering
draw();
models[1].transform.rotation.y -= models[1].transform.rotation.z; // turn the car back for the physics
fps++;
SDL_UpdateTexture(textureSDL,NULL,pixels,S3L_RESOLUTION_X * sizeof(uint32_t));
clock_t nowT = clock();
double timeDiff = ((double) (nowT - nextPrintT)) / CLOCKS_PER_SEC;
double frameDiff = ((double) (nowT - frameStartT)) / CLOCKS_PER_SEC;
int16_t frameDiffMs = frameDiff * 1000;
if (timeDiff >= 1.0)
{
nextPrintT = nowT;
printf("FPS: %d\n",fps);
fps = 0;
}
while (SDL_PollEvent(&event))
if (event.type == SDL_QUIT)
running = 0;
const uint8_t *state = SDL_GetKeyboardState(NULL);
int16_t step = (velocity * frameDiffMs) / 1000;
int16_t stepFriction = (FRICTION * frameDiffMs) / 1000;
int16_t stepRotation = TURN_SPEED * frameDiffMs * S3L_max(0,velocity - 200) / (MAX_VELOCITY * 1000);
int16_t stepVelocity = S3L_nonZero((ACCELERATION * frameDiffMs) / 1000);
if (stepRotation == 0 && S3L_abs(velocity) >= 200)
stepRotation = 1;
if (velocity < 0)
stepRotation *= -1;
if (state[SDL_SCANCODE_LEFT])
{
models[1].transform.rotation.y += stepRotation;
models[1].transform.rotation.z =
S3L_min(S3L_abs(velocity) / 64, models[1].transform.rotation.z + 1);
}
else if (state[SDL_SCANCODE_RIGHT])
{
models[1].transform.rotation.y -= stepRotation;
models[1].transform.rotation.z =
S3L_max(-S3L_abs(velocity) / 64, models[1].transform.rotation.z - 1);
}
else
models[1].transform.rotation.z = (models[1].transform.rotation.z * 3) / 4;
S3L_rotationToDirections(models[1].transform.rotation,S3L_FRACTIONS_PER_UNIT,&carDirection,0,0);
S3L_Vec4 previousCarPos = models[1].transform.translation;
int16_t friction = 0;
if (state[SDL_SCANCODE_UP])
velocity = S3L_min(MAX_VELOCITY,velocity + (velocity < 0 ? (2 * stepVelocity) : stepVelocity));
else if (state[SDL_SCANCODE_DOWN])
velocity = S3L_max(-MAX_VELOCITY,velocity - (velocity > 0 ? (2 * stepVelocity) : stepVelocity));
else
friction = 1;
models[1].transform.translation.x += (carDirection.x * step) / S3L_FRACTIONS_PER_UNIT;
models[1].transform.translation.z += (carDirection.z * step) / S3L_FRACTIONS_PER_UNIT;
uint8_t coll = collision(models[1].transform.translation);
if (coll != 0)
{
if (coll == 1)
{
handleCollision(&(models[1].transform.translation),previousCarPos);
friction = 2;
}
else if (coll == 2)
{
// teleport the car
models[1].transform.translation.x += 5 * S3L_FRACTIONS_PER_UNIT;
models[1].transform.translation.z += 2 * S3L_FRACTIONS_PER_UNIT;
}
else
{
// teleport the car
models[1].transform.translation.x -= 5 * S3L_FRACTIONS_PER_UNIT;
models[1].transform.translation.z -= 2 * S3L_FRACTIONS_PER_UNIT;
}
}
if (velocity > 0)
velocity = S3L_max(0,velocity - stepFriction * friction);
else
velocity = S3L_min(0,velocity + stepFriction * friction);
S3L_Unit cameraDistance =
S3L_interpolate(S3L_FRACTIONS_PER_UNIT / 2,(3 * S3L_FRACTIONS_PER_UNIT) / 4,S3L_abs(velocity),MAX_VELOCITY);
scene.camera.transform.translation.x =
scene.models[1].transform.translation.x - (carDirection.x * cameraDistance) / S3L_FRACTIONS_PER_UNIT;
scene.camera.transform.translation.z =
scene.models[1].transform.translation.z - (carDirection.z * cameraDistance) / S3L_FRACTIONS_PER_UNIT;
scene.camera.transform.rotation.y = models[1].transform.rotation.y;
SDL_RenderClear(renderer);
SDL_RenderCopy(renderer,textureSDL,NULL,NULL);
SDL_RenderPresent(renderer);
frame++;
}
return 0;
}