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/*
* Copyright (C) 2020 - Vito Caputo - <vcaputo@pengaru.com>
*
* This program is free software: you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published
* by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <errno.h>
#include <stdlib.h>
#include <unistd.h>
#include "til.h"
#include "til_fb.h"
#include "puddle/puddle.h"
#define PUDDLE_SIZE 512
#define DRIZZLE_CNT 20
#define DEFAULT_VISCOSITY .01
typedef struct v3f_t {
float x, y, z;
} v3f_t;
typedef struct v2f_t {
float x, y;
} v2f_t;
typedef struct drizzle_setup_t {
til_setup_t til_setup;
float viscosity;
} drizzle_setup_t;
typedef struct drizzle_context_t {
puddle_t *puddle;
drizzle_setup_t setup;
} drizzle_context_t;
static drizzle_setup_t drizzle_default_setup = {
.viscosity = DEFAULT_VISCOSITY,
};
/* convert a color into a packed, 32-bit rgb pixel value (taken from libs/ray/ray_color.h) */
static inline uint32_t color_to_uint32(v3f_t color) {
uint32_t pixel;
if (color.x > 1.0f) color.x = 1.0f;
if (color.y > 1.0f) color.y = 1.0f;
if (color.z > 1.0f) color.z = 1.0f;
if (color.x < .0f) color.x = .0f;
if (color.y < .0f) color.y = .0f;
if (color.z < .0f) color.z = .0f;
pixel = (uint32_t)(color.x * 255.0f);
pixel <<= 8;
pixel |= (uint32_t)(color.y * 255.0f);
pixel <<= 8;
pixel |= (uint32_t)(color.z * 255.0f);
return pixel;
}
static void * drizzle_create_context(unsigned ticks, unsigned n_cpus, til_setup_t *setup)
{
drizzle_context_t *ctxt;
if (!setup)
setup = &drizzle_default_setup.til_setup;
ctxt = calloc(1, sizeof(drizzle_context_t));
if (!ctxt)
return NULL;
ctxt->puddle = puddle_new(PUDDLE_SIZE, PUDDLE_SIZE);
if (!ctxt->puddle) {
free(ctxt);
return NULL;
}
ctxt->setup = *(drizzle_setup_t *)setup;
return ctxt;
}
static void drizzle_destroy_context(void *context)
{
drizzle_context_t *ctxt = context;
puddle_free(ctxt->puddle);
free(ctxt);
}
static void drizzle_prepare_frame(void *context, unsigned ticks, unsigned n_cpus, til_fb_fragment_t *fragment, til_fragmenter_t *res_fragmenter)
{
drizzle_context_t *ctxt = context;
*res_fragmenter = til_fragmenter_slice_per_cpu;
for (int i = 0; i < DRIZZLE_CNT; i++) {
int x = rand() % (PUDDLE_SIZE - 1);
int y = rand() % (PUDDLE_SIZE - 1);
/* TODO: puddle should probably offer a normalized way of setting an
* area to a value, so if PUDDLE_SIZE changes this automatically
* would adapt to cover the same portion of the unit square...
*/
puddle_set(ctxt->puddle, x, y, 1.f);
puddle_set(ctxt->puddle, x + 1, y, 1.f);
puddle_set(ctxt->puddle, x, y + 1, 1.f);
puddle_set(ctxt->puddle, x + 1, y + 1, 1.f);
}
puddle_tick(ctxt->puddle, ctxt->setup.viscosity);
}
static void drizzle_render_fragment(void *context, unsigned ticks, unsigned cpu, til_fb_fragment_t *fragment)
{
drizzle_context_t *ctxt = context;
float xf = 1.f / (float)fragment->frame_width;
float yf = 1.f / (float)fragment->frame_height;
v2f_t coord;
coord.y = yf * (float)fragment->y;
for (int y = fragment->y; y < fragment->y + fragment->height; y++) {
coord.x = xf * (float)fragment->x;
for (int x = fragment->x; x < fragment->x + fragment->width; x++) {
v3f_t color = {};
uint32_t pixel;
color.z = puddle_sample(ctxt->puddle, &coord);
pixel = color_to_uint32(color);
til_fb_fragment_put_pixel_unchecked(fragment, x, y, pixel);
coord.x += xf;
}
coord.y += yf;
}
}
static int drizzle_setup(const til_settings_t *settings, til_setting_t **res_setting, const til_setting_desc_t **res_desc, til_setup_t **res_setup)
{
const char *viscosity;
const char *values[] = {
".005",
".01",
".03",
".05",
NULL
};
int r;
r = til_settings_get_and_describe_value(settings,
&(til_setting_desc_t){
.name = "Puddle viscosity",
.key = "viscosity",
.regex = "\\.[0-9]+",
.preferred = TIL_SETTINGS_STR(DEFAULT_VISCOSITY),
.values = values,
.annotations = NULL
},
&viscosity,
res_setting,
res_desc);
if (r)
return r;
if (res_setup) {
drizzle_setup_t *setup;
setup = til_setup_new(sizeof(*setup), (void(*)(til_setup_t *))free);
if (!setup)
return -ENOMEM;
sscanf(viscosity, "%f", &setup->viscosity);
*res_setup = &setup->til_setup;
}
return 0;
}
til_module_t drizzle_module = {
.create_context = drizzle_create_context,
.destroy_context = drizzle_destroy_context,
.prepare_frame = drizzle_prepare_frame,
.render_fragment = drizzle_render_fragment,
.name = "drizzle",
.description = "Classic 2D rain effect (threaded (poorly))",
.author = "Vito Caputo <vcaputo@pengaru.com>",
.setup = drizzle_setup,
};
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