#include <stdio.h> // sprintf()#include <math.h>#include "ft2_header.h"#include "ft2_gui.h"#include "ft2_pattern_ed.h"#include "ft2_bmp.h"#include "ft2_video.h"#include "ft2_structs.h" #define NUM_STARS 2048#define ALPHA_FADE_MILLISECS 2100 /* amount of milliseconds until content is fully faded in */#define ABOUT_SCREEN_W 626#define ABOUT_SCREEN_H 167#define ABOUT_LOGO_W 449#define ABOUT_LOGO_H 110#define ABOUT_TEXT_W 349#define ABOUT_TEXT_H 29 typedef struct{	float x, y, z;} vector_t; typedef struct{	vector_t x, y, z;} matrix_t; static char *customText1 = "Clone by Olav \"8bitbubsy\" S\025rensen";static char *customText2 = "https://16-bits.org";static char customText3[256];static int16_t customText1Y, customText2Y, customText3Y, customText1X, customText2X, customText3X;static uint32_t alphaValue, randSeed, frameCounter;static vector_t starPoints[NUM_STARS], rotation;static matrix_t matrix; void seedAboutScreenRandom(uint32_t newseed){	randSeed = newseed;} static int32_t random32(void){	randSeed *= 134775813;	randSeed += 1;	return randSeed;} static void rotateMatrix(void){#define MY_PI_FLOAT 3.141592653589793f 	const float xx = rotation.x * MY_PI_FLOAT;	const float sa = sinf(xx);	const float ca = cosf(xx); 	const float yy = rotation.y * MY_PI_FLOAT;	const float sb = sinf(yy);	const float cb = cosf(yy); 	const float zz = rotation.z * MY_PI_FLOAT;	const float sc = sinf(zz);	const float cc = cosf(zz); 	// x	matrix.x.x = (ca * cc) + (sc * sa * sb);	matrix.y.x = sa * cb;	matrix.z.x = (cc * sa * sb) - (ca * sc); 	// y	matrix.x.y = (sc * ca * sb) - (sa * cc);	matrix.y.y = ca * cb;	matrix.z.y = (sa * sc) + (cc * ca * sb); 	// z	matrix.x.z = cb * sc;	matrix.y.z = -sb;	matrix.z.z = cb * cc;} static void aboutInit(void){	vector_t *s = starPoints;	for (int32_t i = 0; i < NUM_STARS; i++, s++)	{		s->x = (float)(random32() * (1.0 / (UINT32_MAX+1.0)));		s->y = (float)(random32() * (1.0 / (UINT32_MAX+1.0)));		s->z = (float)(random32() * (1.0 / (UINT32_MAX+1.0)));	} 	rotation.x = rotation.y = rotation.z = 0.0f;	alphaValue = 0;	frameCounter = 0;} static void starfield(void){	vector_t *star = starPoints;	for (int16_t i = 0; i < NUM_STARS; i++, star++)	{		star->z += 0.00015f;		if (star->z >= 0.5f)			star->z -= 1.0f; 		const float z = (matrix.x.z * star->x) + (matrix.y.z * star->y) + (matrix.z.z * star->z) + 0.5f;		if (z <= 0.0f)			continue; 		float y = (ABOUT_SCREEN_H/2.0f) + ((((matrix.x.y * star->x) + (matrix.y.y * star->y) + (matrix.z.y * star->z)) / z) * 400.0f);		const int32_t outY = (int32_t)y;		if (outY < 3 || outY >= 3+ABOUT_SCREEN_H)			continue; 		float x = (ABOUT_SCREEN_W/2.0f) + ((((matrix.x.x * star->x) + (matrix.y.x * star->y) + (matrix.z.x * star->z)) / z) * 400.0f); 		const int32_t outX = (int32_t)x;		if (outX < 3 || outX >= 3+ABOUT_SCREEN_W)			continue; 		int32_t d = (int32_t)(z * 255.0f);		if (d > 255)			d = 255;		d ^= 255; 		// add a tint of blue to the star pixel 		int32_t r = d - 79;		if (r < 0)			r = 0; 		int32_t g = d - 38;		if (g < 0)			g = 0; 		int32_t b = d + 64;		if (b > 255)			b = 255; 		video.frameBuffer[(outY * SCREEN_W) + outX] = RGB32(r, g, b);	}} void aboutFrame(void) // called every frame when the about screen is shown{	clearRect(3, 3, ABOUT_SCREEN_W, ABOUT_SCREEN_H); 	// 3D starfield	rotateMatrix();	starfield();	rotation.x -= 0.00011f;	rotation.z += 0.00006f; 	// logo + text	blit32Alpha(91, 31, bmp.ft2AboutLogo, ABOUT_LOGO_W, ABOUT_LOGO_H, alphaValue);	textOutAlpha(customText1X, customText1Y, PAL_FORGRND, customText1, alphaValue);	textOutAlpha(customText2X, customText2Y, PAL_FORGRND, customText2, alphaValue);	textOutAlpha(customText3X, customText3Y, PAL_FORGRND, customText3, alphaValue); 	alphaValue += (uint32_t)((65536.0 / (ALPHA_FADE_MILLISECS / (1000.0 / VBLANK_HZ))) + 0.5);	if (alphaValue > 65536)		alphaValue = 65536; 	// the exit button has to be redrawn since it gets overwritten :)	showPushButton(PB_EXIT_ABOUT);} void showAboutScreen(void) // called once when about screen is opened{	if (ui.extended)		exitPatternEditorExtended(); 	hideTopScreen(); 	drawFramework(0, 0, 632, 173, FRAMEWORK_TYPE1);	drawFramework(2, 2, 628, 169, FRAMEWORK_TYPE2); 	showPushButton(PB_EXIT_ABOUT); 	sprintf(customText3, "v%s (%s)", PROG_VER_STR, __DATE__);	customText1X = (SCREEN_W - textWidth(customText1)) / 2;	customText2X = (SCREEN_W-8) - textWidth(customText2);	customText3X = (SCREEN_W-8) - textWidth(customText3);	customText1Y = 157;	customText2Y = 157-12;	customText3Y = 157; 	aboutInit();	ui.aboutScreenShown = true;} void hideAboutScreen(void){	hidePushButton(PB_EXIT_ABOUT);	ui.aboutScreenShown = false;} void exitAboutScreen(void){	hideAboutScreen();	showTopScreen(true);}