ref: 48af8f2a6f60a3598a3186f16008848edf5f66e9
dir: /src/ft2_about.c/
#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 3000
#define ALPHA_FADE_MILLISECS 2000 /* 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 logoTimer, 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;
logoTimer = 0;
}
static void blendPixel(int32_t x, int32_t y, int32_t r, int32_t g, int32_t b, int32_t alpha)
{
uint32_t *p = &video.frameBuffer[(y * SCREEN_W) + x];
const uint32_t srcPixel = *p;
const int32_t srcR = RGB32_R(srcPixel);
const int32_t srcG = RGB32_G(srcPixel);
const int32_t srcB = RGB32_B(srcPixel);
r = ((srcR * (65536-alpha)) + (r * alpha)) >> 16;
g = ((srcG * (65536-alpha)) + (g * alpha)) >> 16;
b = ((srcB * (65536-alpha)) + (b * alpha)) >> 16;
*p = RGB32(r, g, b);
}
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;
// blend sides of star
const int32_t sidesAlpha = 13000;
if (outX-1 >= 3)
blendPixel(outX-1, outY, r, g, b, sidesAlpha);
if (outX+1 < 3+ABOUT_SCREEN_W)
blendPixel(outX+1, outY, r, g, b, sidesAlpha);
if (outY-1 >= 3)
blendPixel(outX, outY-1, r, g, b, sidesAlpha);
if (outY+1 < 3+ABOUT_SCREEN_H)
blendPixel(outX, outY+1, r, g, b, sidesAlpha);
// plot main star pixel
blendPixel(outX, outY, r, g, b, 60000);
}
}
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);
if (logoTimer > (int32_t)(VBLANK_HZ/4.0))
{
alphaValue += (uint32_t)((65536.0 / (ALPHA_FADE_MILLISECS / (1000.0 / VBLANK_HZ))) + 0.5);
if (alphaValue > 65536)
alphaValue = 65536;
}
else
{
logoTimer++;
}
// 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);
}