nds_nflib/examples/demo/water/source/main.c

146 lines
3.8 KiB
C

// SPDX-License-Identifier: CC0-1.0
//
// SPDX-FileContributor: NightFox & Co., 2009-2011
//
// Water reflection effect (with scroll).
// http://www.nightfoxandco.com
#include <stdio.h>
#include <nds.h>
#include <filesystem.h>
#include <nf_lib.h>
// Wave effect variables
u16 mapa[32][24]; // Map
s16 bgx[192]; // X scroll of each line
s8 i[192]; // Movement control of each line
// Background control variables
s16 bg_x[4];
// Function that runs after a scanline is drawn. By modifying the values of the
// scroll registers it's possible to add a wave effect.
void hblank_handler(void)
{
u32 vline = REG_VCOUNT; // Get the current line
if ((vline >= 138) && (vline <= 159))
{
// If the current line is between 138 and 159, apply effect to layer 1
bgx[vline] += i[vline];
if ((bgx[vline] < 1) || (bgx[vline] > 63))
i[vline] *= -1;
NF_ScrollBg(0, 1, bg_x[1] + ((bgx[vline] / 8) - 4), 0);
}
if ((vline >= 160) && (vline <= 191))
{
// If the current line is between 160 and 191, apply effect to layer 0
bgx[vline] += i[vline];
if ((bgx[vline] < 1) || (bgx[vline] > (vline - 156)))
i[vline] *= -1;
NF_ScrollBg(0, 0, bg_x[0] + (((vline - 156) / 2) - bgx[vline]), 0);
}
}
int main(int argc, char **argv)
{
// Prepare a NitroFS initialization screen
NF_Set2D(0, 0);
NF_Set2D(1, 0);
consoleDemoInit();
printf("\n NitroFS init. Please wait.\n\n");
printf(" Iniciando NitroFS,\n por favor, espere.\n\n");
swiWaitForVBlank();
// Initialize NitroFS and set it as the root folder of the filesystem
nitroFSInit(NULL);
NF_SetRootFolder("NITROFS");
// Initialize 2D engine in both screens and use mode 0
NF_Set2D(0, 0);
NF_Set2D(1, 0);
// Initialize tiled backgrounds system
NF_InitTiledBgBuffers(); // Initialize storage buffers
NF_InitTiledBgSys(0); // Top screen
NF_InitTiledBgSys(1); // Bottom screen
// Load background files from NitroFS
NF_LoadTiledBg("bg/layer0", "layer0", 512, 256);
NF_LoadTiledBg("bg/layer1", "layer1", 512, 256);
NF_LoadTiledBg("bg/layer2", "layer2", 512, 256);
NF_LoadTiledBg("bg/layer3", "layer3", 512, 256);
NF_LoadTiledBg("bg/nfl", "nfl", 256, 256);
// Create top screen backgrounds
NF_CreateTiledBg(0, 3, "layer3");
NF_CreateTiledBg(0, 2, "layer2");
NF_CreateTiledBg(0, 1, "layer1");
NF_CreateTiledBg(0, 0, "layer0");
// Create bottom screen backgrounds
NF_CreateTiledBg(1, 3, "nfl");
// Initialize wave effect
s16 y = 0;
s8 inc = 1;
for (y = 138; y < 192; y++)
{
// Layer 1 calculations
if ((y >= 138) && (y <= 159))
{
bgx[y] = 32;
inc *= -1;
i[y] = inc;
}
// Layer 0 calculations
if ((y >= 160) && (y <= 191))
{
bgx[y] = (y - 156) / 2;
i[y] = inc;
inc *= -1;
}
}
// Register a function to be called after a screen line has been drawn (when
// the horizontal blanking period starts)
irqSet(IRQ_HBLANK, hblank_handler);
irqEnable(IRQ_HBLANK);
while (1)
{
scanKeys(); // Read keypad
u16 keys = keysHeld(); // Keys currently pressed
// Move background
if ((keys & KEY_LEFT) && (bg_x[0] > 8))
bg_x[0]--;
if ((keys & KEY_RIGHT) && (bg_x[0] < 247))
bg_x[0]++;
// Calculate parallax
bg_x[1] = bg_x[0] / 1.5;
bg_x[2] = bg_x[1] / 1.5;
bg_x[3] = bg_x[2] / 1.5;
// Wait for the screen refresh
swiWaitForVBlank();
// Scroll all backgrounds
NF_ScrollBg(0, 3, bg_x[3], 0);
NF_ScrollBg(0, 2, bg_x[2], 0);
NF_ScrollBg(0, 1, bg_x[1], 0);
NF_ScrollBg(0, 0, bg_x[0], 0);
}
return 0;
}