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perlin2d, sample terrain render

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This commit is contained in:
veclav talica 2024-07-30 19:36:59 +03:00
parent a4cb50687e
commit 94ce701dae
8 changed files with 117 additions and 15 deletions
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1
CMakeLists.txt
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@ -48,6 +48,7 @@ set(TOWNENGINE_SOURCE_FILES
src/text.c src/text.h
src/camera.c src/camera.h
src/textures/textures.c
src/procgen/perlin2d.c
${SYSTEM_SOURCE_FILES}
)

39
apps/testgame/scenes/ingame.c
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@ -11,7 +11,8 @@ static void ingame_tick(struct state *state) {
world_drawdef(scn->world);
player_calc(scn->player);
static t_camera cam = { .pos = { 0, 0, 1 }, .target = { 0, 0, -1 }, .up = { 0, 1, 0 }, .fov = (float)M_PI_2 };
static t_camera cam = { .pos = { 32, 0, 1 }, .up = { 0, 1, 0 }, .fov = (float)M_PI_2 };
cam.target = m_vec_norm(((t_fvec3){ -1, 0, 1 }));
if (input_is_action_pressed(&ctx.input, "player_left"))
cam.pos.x -= 0.01f;
@ -42,21 +43,29 @@ static void ingame_tick(struct state *state) {
set_camera(&cam);
unfurl_triangle("/assets/big-violet.png",
(t_fvec3){ -1, -1, 0 },
(t_fvec3){ 1, -1, 0 },
(t_fvec3){ 1, 1, 0 },
(t_shvec2){ 0, 2048 },
(t_shvec2){ 2048, 2048 },
(t_shvec2){ 2048, 0 });
for (int y = 64; --y;)
for (int x = 64; --x;) {
float d0 = sample_perlin_2d((t_fvec2){x, y}, 0.2, 5) * 8 - 6;
float d1 = sample_perlin_2d((t_fvec2){x + 1, y}, 0.2, 5) * 8 - 6;
float d2 = sample_perlin_2d((t_fvec2){x + 1, y - 1}, 0.2, 5) * 8 - 6;
float d3 = sample_perlin_2d((t_fvec2){x, y - 1}, 0.2, 5) * 8 - 6;
unfurl_triangle("/assets/big-violet.png",
(t_fvec3){ 1, 1, 0 },
(t_fvec3){ -1, 1, 0 },
(t_fvec3){ -1, -1, 0 },
(t_shvec2){ 2048, 0 },
(t_shvec2){ 0, 0 },
(t_shvec2){ 0, 2048 });
unfurl_triangle("/assets/grass.gif",
(t_fvec3){ x, d0, y },
(t_fvec3){ x + 1, d1, y },
(t_fvec3){ x, d3, y - 1 },
(t_shvec2){ 0, 768 },
(t_shvec2){ 1024, 768 },
(t_shvec2){ 1024, 0 });
unfurl_triangle("/assets/grass.gif",
(t_fvec3){ x + 1, d1, y },
(t_fvec3){ x + 1, d2, y - 1 },
(t_fvec3){ x, d3, y - 1 },
(t_shvec2){ 1024, 0 },
(t_shvec2){ 0, 0 },
(t_shvec2){ 0, 768 });
}
}

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1
src/game_api.h
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@ -7,6 +7,7 @@
#include "rendering.h"
#include "audio.h"
#include "util.h"
#include "procgen.h"
/* application provided */
extern void game_tick(void);

6
src/procgen.h Normal file
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@ -0,0 +1,6 @@
#ifndef PROCGEN_H
#define PROCGEN_H
#include "procgen/perlin.h"
#endif

10
src/procgen/perlin.h Normal file
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@ -0,0 +1,10 @@
#ifndef PROCGEN_PERLIN_H
#define PROCGEN_PERLIN_H
#include "../vec.h"
void set_perlin_2d_seed(uint32_t seed);
float sample_perlin_2d(t_fvec2 position, float frequency, uint8_t octaves);
#endif

70
src/procgen/perlin2d.c Normal file
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@ -0,0 +1,70 @@
#include "perlin.h"
#include "../vec.h"
static uint32_t seed = 0;
static const uint8_t hash[] = { 208,34,231,213,32,248,233,56,161,78,24,140,71,48,140,254,245,255,247,247,40,
185,248,251,245,28,124,204,204,76,36,1,107,28,234,163,202,224,245,128,167,204,
9,92,217,54,239,174,173,102,193,189,190,121,100,108,167,44,43,77,180,204,8,81,
70,223,11,38,24,254,210,210,177,32,81,195,243,125,8,169,112,32,97,53,195,13,
203,9,47,104,125,117,114,124,165,203,181,235,193,206,70,180,174,0,167,181,41,
164,30,116,127,198,245,146,87,224,149,206,57,4,192,210,65,210,129,240,178,105,
228,108,245,148,140,40,35,195,38,58,65,207,215,253,65,85,208,76,62,3,237,55,89,
232,50,217,64,244,157,199,121,252,90,17,212,203,149,152,140,187,234,177,73,174,
193,100,192,143,97,53,145,135,19,103,13,90,135,151,199,91,239,247,33,39,145,
101,120,99,3,186,86,99,41,237,203,111,79,220,135,158,42,30,154,120,67,87,167,
135,176,183,191,253,115,184,21,233,58,129,233,142,39,128,211,118,137,139,255,
114,20,218,113,154,27,127,246,250,1,8,198,250,209,92,222,173,21,88,102,219 };
void set_perlin_2d_seed(uint32_t s) {
seed = s;
}
static int32_t noise2(int x, int y)
{
int tmp = hash[(y + seed) % 256];
return hash[(tmp + x) % 256];
}
static float lin_inter(float x, float y, float s)
{
return x + s * (y-x);
}
static float smooth_inter(float x, float y, float s)
{
return lin_inter(x, y, s * s * (3-2*s));
}
static float noise2d(float x, float y)
{
int32_t x_int = (int32_t)x;
int32_t y_int = (int32_t)y;
float x_frac = x - (float)x_int;
float y_frac = y - (float)y_int;
int32_t s = noise2(x_int, y_int);
int32_t t = noise2(x_int + 1, y_int);
int32_t u = noise2(x_int, y_int + 1);
int v = noise2(x_int + 1, y_int + 1);
float low = smooth_inter((float)s, (float)t, x_frac);
float high = smooth_inter((float)u, (float)v, x_frac);
return smooth_inter(low, high, y_frac);
}
/* https://gist.github.com/nowl/828013 */
float sample_perlin_2d(t_fvec2 position, float frequency, uint8_t octaves) {
t_fvec2 a = m_vec_scale(position, frequency);
float amp = 1.0;
float fin = 0;
float div = 0.0;
for(uint8_t i = 0; i < octaves; i++)
{
div += 256 * amp;
fin += noise2d(a.x, a.y) * amp;
amp /= 2;
a = m_vec_scale(a, 2);
}
return fin/div;
}

5
src/vec.h
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@ -70,6 +70,10 @@ static inline t_fvec3 fvec3_sub(t_fvec3 a, t_fvec3 b) {
return (t_fvec3) { a.x - b.x, a.y - b.y, a.z - b.z };
}
static inline t_fvec2 fvec2_scale(t_fvec2 a, float s) {
return (t_fvec2) { a.x * s, a.y * s };
}
static inline t_fvec3 fvec3_scale(t_fvec3 a, float s) {
return (t_fvec3) { a.x * s, a.y * s, a.z * s };
}
@ -103,6 +107,7 @@ static inline t_fvec3 fvec3_norm(t_fvec3 a) {
)(p_any_vec0, p_any_vec1))
#define m_vec_scale(p_any_vec, p_any_scalar) (_Generic((p_any_vec), \
t_fvec2: fvec2_scale, \
t_fvec3: fvec3_scale \
)(p_any_vec, p_any_scalar))