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/*
* LibPSn00b Example Programs
*
* GTE Billboarding Sprites Example
* 2019 - 2021 Meido-Tek Productions / PSn00bSDK Project
*
* Displays a bunch of sprites placed on the screen using 3D coordinates
* that scale according to the distance from the screen. This is a quick
* modification of the GTE cube example.
*
* Billboard sprites are useful for 2D projectiles flying across 3D space,
* particle effects such as smoke as well as characters and objects
* represented as 2D sprites.
*
* Example by Lameguy64
*
* Changelog:
*
* May 10, 2021 - Variable types updated for psxgpu.h changes.
*
* Sep 24, 2019 - Initial version.
*
*/
#include <sys/types.h>
#include <stdio.h>
#include <psxgpu.h>
#include <psxgte.h>
#include <inline_c.h>
/* OT and Packet Buffer sizes */
#define OT_LEN 256
#define PACKET_LEN 1024
/* Screen resolution */
#define SCREEN_XRES 320
#define SCREEN_YRES 240
/* Screen center position */
#define CENTERX SCREEN_XRES>>1
#define CENTERY SCREEN_YRES>>1
/* Double buffer structure */
typedef struct {
DISPENV disp; /* Display environment */
DRAWENV draw; /* Drawing environment */
u_long ot[OT_LEN]; /* Ordering table */
char p[PACKET_LEN]; /* Packet buffer */
} DB;
/* Double buffer variables */
DB db[2];
int db_active = 0;
char *db_nextpri;
extern u_long tim_image[];
TIM_IMAGE tim;
/* For easier handling of vertex indices */
typedef struct {
short v0,v1,v2,v3;
} INDEX;
/* Sprite position vertices */
SVECTOR verts[] = {
{ -50, -50, -50, 0 },
{ 50, -50, -50, 0 },
{ -50, 50, -50, 0 },
{ 50, 50, -50, 0 },
{ 50, -50, 50, 0 },
{ -50, -50, 50, 0 },
{ 50, 50, 50, 0 },
{ -50, 50, 50, 0 }
};
/* Function declarations */
void init();
void display();
/* Main function */
int main() {
int i,p,sz;
SVECTOR rot = { 0 }; /* Rotation vector for Rotmatrix */
VECTOR pos = { 0, 0, 160 }; /* Translation vector for TransMatrix */
MATRIX mtx,lmtx; /* Rotation matrices for geometry and lighting */
POLY_FT4 *quad; /* Flat shaded quad primitive pointer */
SVECTOR spos;
/* Init graphics and GTE */
init();
/* Main loop */
while( 1 ) {
/* Set rotation and translation to the matrix */
RotMatrix( &rot, &mtx );
TransMatrix( &mtx, &pos );
/* Set rotation and translation matrix */
gte_SetRotMatrix( &mtx );
gte_SetTransMatrix( &mtx );
/* Make the sprites revolve around */
rot.vy += 16;
rot.vz += 16;
/* Draw the sprites */
quad = (POLY_FT4*)db_nextpri;
for( i=0; i<8; i++ ) {
// Load the 3D coordinate of the sprite to GTE
gte_ldv0(&verts[i]);
// Rotation, Translation and Perspective Single
gte_rtps();
// Store depth
gte_stsz(&p);
// Don't sort sprite if depth is zero
// (or divide by zero will happen later)
if( p > 0 ) {
// Store result to position vector
gte_stsxy2(&spos);
// Calculate sprite size, the divide operation might be a
// performance killer but it's likely faster than performing
// a lookat operation between sprite and camera, which some
// billboard sprite implementations use.
sz = (16*CENTERX)/p;
// Prepare quad primitive
setPolyFT4(quad);
// Set quad coordinates
setXY4(quad,
spos.vx-sz, spos.vy-sz,
spos.vx+sz, spos.vy-sz,
spos.vx-sz, spos.vy+sz,
spos.vx+sz, spos.vy+sz);
// Set color
setRGB0(quad, 128, 128, 128);
// Set tpage
quad->tpage = getTPage(tim.mode, 0, tim.prect->x, tim.prect->y);
// Set CLUT
setClut(quad, tim.crect->x, tim.crect->y);
// Set texture coordinates
setUVWH(quad, 0, 0, 64, 64);
/* Sort primitive to the ordering table */
addPrim(db[db_active].ot+(p>>2), quad);
/* Advance to make another primitive */
quad++;
}
}
/* Update nextpri variable */
/* (IMPORTANT if you plan to sort more primitives after this) */
db_nextpri = (char*)quad;
/* Swap buffers and draw the primitives */
display();
}
return 0;
}
void init() {
/* Reset the GPU, also installs a VSync event handler */
ResetGraph( 0 );
/* Set display and draw environment areas */
/* (display and draw areas must be separate, otherwise hello flicker) */
SetDefDispEnv( &db[0].disp, 0, 0, SCREEN_XRES, SCREEN_YRES );
SetDefDrawEnv( &db[0].draw, SCREEN_XRES, 0, SCREEN_XRES, SCREEN_YRES );
/* Enable draw area clear and dither processing */
setRGB0( &db[0].draw, 63, 0, 127 );
db[0].draw.isbg = 1;
db[0].draw.dtd = 1;
/* Define the second set of display/draw environments */
SetDefDispEnv( &db[1].disp, SCREEN_XRES, 0, SCREEN_XRES, SCREEN_YRES );
SetDefDrawEnv( &db[1].draw, 0, 0, SCREEN_XRES, SCREEN_YRES );
setRGB0( &db[1].draw, 63, 0, 127 );
db[1].draw.isbg = 1;
db[1].draw.dtd = 1;
/* Apply the drawing environment of the first double buffer */
PutDrawEnv( &db[0].draw );
/* Clear both ordering tables to make sure they are clean at the start */
ClearOTagR( db[0].ot, OT_LEN );
ClearOTagR( db[1].ot, OT_LEN );
/* Set primitive pointer address */
db_nextpri = db[0].p;
/* Initialize the GTE */
InitGeom();
/* Set GTE offset (recommended method of centering) */
gte_SetGeomOffset( CENTERX, CENTERY );
/* Set screen depth (basically FOV control, W/2 works best) */
gte_SetGeomScreen( CENTERX );
GetTimInfo( tim_image, &tim);
LoadImage(tim.prect, tim.paddr);
DrawSync(0);
LoadImage(tim.crect, tim.caddr);
DrawSync(0);
}
void display() {
/* Wait for GPU to finish drawing and vertical retrace */
DrawSync( 0 );
VSync( 0 );
/* Swap buffers */
db_active ^= 1;
db_nextpri = db[db_active].p;
/* Clear the OT of the next frame */
ClearOTagR( db[db_active].ot, OT_LEN );
/* Apply display/drawing environments */
PutDrawEnv( &db[db_active].draw );
PutDispEnv( &db[db_active].disp );
/* Enable display */
SetDispMask( 1 );
/* Start drawing the OT of the last buffer */
DrawOTag( db[1-db_active].ot+(OT_LEN-1) );
}
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