skcblitz/framebuf.h

byte fb_init_int(uint *fbo, uint *fbtex, uint *rbo, byte linear) {
	uint status;
	glGenFramebuffers(1, fbo);
	glBindFramebuffer(GL_FRAMEBUFFER, *fbo);
	glGenTextures(1, fbtex);
	glBindTexture(GL_TEXTURE_2D, *fbtex);
	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 16, 16, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, linear ? GL_LINEAR : GL_NEAREST);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, linear ? GL_LINEAR : GL_NEAREST);
	glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, *fbtex, 0);
	if(rbo) {
		glGenRenderbuffers(1, rbo);
		glBindRenderbuffer(GL_RENDERBUFFER, *rbo);
		glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT24, 16, 16);
		glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, *rbo);
	}
	if((status = glCheckFramebufferStatus(GL_FRAMEBUFFER)) != GL_FRAMEBUFFER_COMPLETE) {
		loge(LOG_GFX, STR_FBO_INCOMPLETE, *fbo, status);
		glBindFramebuffer(GL_FRAMEBUFFER, 0);
		glDeleteTextures(1, fbtex);
		glDeleteFramebuffers(1, fbo);
		if(rbo) {
			glDeleteRenderbuffers(1, rbo);
		}
		return 0;
	}
	glBindFramebuffer(GL_FRAMEBUFFER, 0);
	gdr.fb_mem += 16 * 16 * 4;
	gdr.fb_peak = gdr.fb_mem > gdr.fb_peak ? gdr.fb_mem : gdr.fb_peak;
	return 1;
}

byte fb_init_sys(uint *fbo, uint *fbtex) {
	if(fb_init_int(fbo, fbtex, NULL, 0)) {
		logd(LOG_GFX, STR_FBO_ADDED, *fbo, *fbtex);
		gdr.fb_loaded += 1;
		return 1;
	}
	return 0;
}

fbo_t *fb_init(uint *fbo, uint *fbtex, uint *rbo, window_t *resize, byte linear) {
	fbo_t *bind;
	if(!fb_init_int(fbo, fbtex, rbo, linear))
		return NULL;
	sys_assert(bind = (fbo_t*)tbl_push(&gdr.framebufs));
	bind->fbo = fbo;
	bind->tex = fbtex;
	bind->rbo = rbo;
	bind->resize = resize;
	bind->linear = linear;
	bind->xsize = 0;
	bind->ysize = 0;
	gdr.fb_loaded += 1;
	if(rbo)
		logd(LOG_GFX, STR_FBO_ADDED_RBO, *fbo, *fbtex, *rbo);
	else
		logd(LOG_GFX, STR_FBO_ADDED, *fbo, *fbtex);
	return bind;
}

void fb_resize_int(uint fbtex, int px, int py, int x, int y) {
	gdr.fb_mem -= px * py * 4;
	glBindTexture(GL_TEXTURE_2D, fbtex);
	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, x, y, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
	gdr.fb_mem += x * y * 4;
	gdr.fb_peak = gdr.fb_mem > gdr.fb_peak ? gdr.fb_mem : gdr.fb_peak;
}

byte fb_resize(fbo_t *buf, window_t *resize) {
	if(!(buf->resize) || (buf->resize != resize))
		return 0;
	glBindTexture(GL_TEXTURE_2D, *(buf->tex));
	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, resize->fb_x, resize->fb_y, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
	if(buf->rbo) {
		glBindRenderbuffer(GL_RENDERBUFFER, *(buf->rbo));
		glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT24, resize->fb_x, resize->fb_y);
	}
	gdr.fb_mem -= buf->xsize * buf->ysize * 4;
	gdr.fb_mem += (buf->xsize = resize->fb_x) * (buf->ysize = resize->fb_y) * 4;
	gdr.fb_peak = gdr.fb_mem > gdr.fb_peak ? gdr.fb_mem : gdr.fb_peak;
	return 1;
}

int fb_reconfig(window_t *resize) {
	int done = 0;
	ulong iter = 0;
	fbo_t *buf;
	while(buf = tbl_iter(&gdr.framebufs, &iter)) {
		done += (int)fb_resize(buf, resize);
	}
	// logd(LOG_GFX, STR_FBO_RESIZE, done);
	return done;
}

void fb_size_int(uint tex, uint rbo, int x, int y) {
	glBindTexture(GL_TEXTURE_2D, tex);
	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, x, y, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
	if(rbo) {
		glBindRenderbuffer(GL_RENDERBUFFER, rbo);
		glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT24, x, y);
	}
}

byte fb_size(fbo_t *buf, int x, int y) {
	fb_size_int(*(buf->tex), buf->rbo ? *(buf->rbo) : 0, x, y);
	gdr.fb_mem -= buf->xsize * buf->ysize * 4;
	gdr.fb_mem += (buf->xsize = x) * (buf->ysize = y) * 4;
	gdr.fb_peak = gdr.fb_mem > gdr.fb_peak ? gdr.fb_mem : gdr.fb_peak;
}

void fb_delete(uint *fbo, uint *fbtex) {
	if(*fbo) {
		glDeleteTextures(1, fbtex);
		glDeleteFramebuffers(1, fbo);
		logd(LOG_GFX, STR_FBO_DELETED, *fbo, *fbtex);
		*fbo = 0;
		*fbtex = 0;
		gdr.fb_loaded -= 1;
	}
}

byte fb_unload(fbo_t *buf) {
	if(!(*(buf->fbo))) {
		return 0;
	}
	glDeleteTextures(1, buf->tex);
	glDeleteFramebuffers(1, buf->fbo);
	if(buf->rbo) {
		glDeleteRenderbuffers(1, buf->rbo);
		logd(LOG_GFX, STR_FBO_DELETED_RBO, *(buf->fbo), *(buf->tex), *(buf->rbo));
		*(buf->rbo) = 0;
	}
	else {
		logd(LOG_GFX, STR_FBO_DELETED, *(buf->fbo), *(buf->tex));
	}
	*(buf->fbo) = 0;
	*(buf->tex) = 0;
	gdr.fb_loaded -= 1;
	return 1;
}

void fb_remove(fbo_t *buf) {
	if(fb_unload(buf)) {
		tbl_pop(&gdr.framebufs, buf);
	}
}

int fb_clear() {
	return tbl_clear_func(&gdr.framebufs, (clear_func*)fb_unload);
}