Merge pull request #36 from spicyjpeg/dynlink

Dynamic linker, gp-relative addressing, ldscripts and more

1 files changed, 116 insertions, 0 deletions

diff --git a/examples/system/dynlink/library/balls.c b/examples/system/dynlink/library/balls.c
new file mode 100644
index 0000000..2a4d9f4
--- /dev/null
+++ b/examples/system/dynlink/library/balls.c
@@ -0,0 +1,116 @@
+/*
+ * PSn00bSDK dynamic linker example (DLL 2)
+ * (C) 2021 spicyjpeg - MPL licensed
+ */
+
+#include <sys/types.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <psxgpu.h>
+#include <psxgte.h>
+#include <psxpad.h>
+#include <inline_c.h>
+
+#include "dll_common.h"
+#include "ball16c.h"
+
+/* Balls data */
+
+typedef struct {
+	int16_t x, y;
+	int16_t xdir, ydir;
+	uint8_t r, g, b, p;
+} BALL_TYPE;
+
+#define MAX_BALLS 512
+
+/* Functions called by the main executable */
+
+// NOTE: DLLs have no main(), _start() or other defined entry point. C++ global
+// objects are automatically constructed when loading the library, and their
+// destructors are called when unloading it via dlclose(). Other than that, the
+// main executable can freely call DLL functions in any order, however it's
+// still recommended (at least for C code) to have an init() function to e.g.
+// initialize variables or hardware.
+
+static uint32_t  frame = 0;
+static BALL_TYPE balls[MAX_BALLS];
+static TIM_IMAGE ball_tim;
+
+void init(CONTEXT *ctx) {
+	GetTimInfo((u_long *) ball16c, &ball_tim);
+
+	LoadImage(ball_tim.prect, ball_tim.paddr);
+	if (ball_tim.mode & 8)
+		LoadImage(ball_tim.crect, ball_tim.caddr);
+
+	// Initialize the balls by giving them a random initial position, velocity
+	// and color.
+	for (uint32_t i = 0; i < MAX_BALLS; i++) {
+		BALL_TYPE *b = &(balls[i]);
+
+		b->x    = rand() % (ctx->xres - 16);
+		b->y    = rand() % (ctx->yres - 16);
+		b->xdir = ((rand() & 1) ? 1 : -1) * ((rand() % 3) + 1);
+		b->ydir = ((rand() & 1) ? 1 : -1) * ((rand() % 3) + 1);
+		b->r    = rand() & 0xff;
+		b->g    = rand() & 0xff;
+		b->b    = rand() & 0xff;
+	}
+}
+
+void render(CONTEXT *ctx, uint16_t buttons) {
+	DB      *db   = &(ctx->db[ctx->db_active]);
+	SPRT_16 *sprt = (SPRT_16 *) ctx->db_nextpri;
+
+	for (uint32_t i = 0; i < MAX_BALLS; i++) {
+		BALL_TYPE *b = &(balls[i]);
+
+		setSprt16(sprt);
+
+		setXY0(sprt, b->x, b->y);
+		setRGB0(sprt, b->r, b->g, b->b);
+		setUV0(sprt, 0, 0);
+		setClut(sprt, ball_tim.crect->x, ball_tim.crect->y);
+
+		addPrim(&(db->ot[OT_LEN - 1]), sprt);
+		sprt++;
+
+		// Update the ball's velocity and acceleration, moving them slower if
+		// cross is pressed.
+		int16_t step = !(buttons & PAD_CROSS) ? 1 : 0;
+		b->x += b->xdir >> step;
+		b->y += b->ydir >> step;
+
+		if (
+			(b->x < 0) ||
+			((b->x + 16) > ctx->xres)
+		)
+			b->xdir *= -1;
+		if (
+			(b->y < 0) ||
+			((b->y + 16) > ctx->yres)
+		)
+			b->ydir *= -1;
+	}
+
+	ctx->db_nextpri = (uint8_t *) sprt;
+
+	// Add a TPAGE "primitive" to ensure the GPU finds the ball texture.
+	DR_TPAGE *tpri = (DR_TPAGE * ) ctx->db_nextpri;
+
+	setDrawTPage(
+		tpri,
+		0,
+		0, 
+		getTPage(0, 0, ball_tim.prect->x, ball_tim.prect->y)
+	);
+	addPrim(&(db->ot[OT_LEN - 1]), tpri);
+	tpri++;
+
+	ctx->db_nextpri = (uint8_t *) tpri;
+
+	// Due to our custom resolver, this will actually call dll_printf() in the
+	// main executable.
+	printf("DRAWING BALLS, COUNTER=%d\n", frame++);
+}