ref: 8458e4fecf79c0f754b18641537ff4c984981e51
parent: 8be2e4c8bceb1e6a8594fcafaa682953cb7d957d
author: Olav Sørensen <olav.sorensen@live.no>
date: Mon Sep 30 10:26:04 EDT 2024
Small code cleanup
--- a/src/ft2_about.c
+++ b/src/ft2_about.c
@@ -9,6 +9,8 @@
#include "ft2_pattern_ed.h" // exitPatternEditorExtended()
#define LOGO_ALPHA_PERCENTAGE 70
+#define STAR_ALPHA_PERCENTAGE 91
+#define STARSHINE_ALPHA_PERCENTAGE 20
#define SINUS_PHASES 1024
#define NUM_STARS 2000
#define ABOUT_SCREEN_X 3
@@ -35,7 +37,7 @@
static int16_t customText0X, customText0Y, customText1Y, customText2Y;
static int16_t customText3Y, customText1X, customText2X, customText3X;
static int16_t sin16[SINUS_PHASES];
-static uint16_t logoAlpha16;
+static uint16_t logoAlpha16, starShineAlpha16, starAlpha16;
static uint32_t randSeed, sinp1, sinp2;
static vector_t starPoints[NUM_STARS], rotation;
static matrix_t matrix;
@@ -56,32 +58,29 @@
{#define MY_2PI_FLOAT 6.2831853071796f
- const float x2pi = rotation.x * MY_2PI_FLOAT;
- const float sa = sinf(x2pi);
- const float ca = cosf(x2pi);
+ const float xsin = sinf(rotation.x * MY_2PI_FLOAT);
+ const float xcos = cosf(rotation.x * MY_2PI_FLOAT);
- const float y2pi = rotation.y * MY_2PI_FLOAT;
- const float sb = sinf(y2pi);
- const float cb = cosf(y2pi);
+ const float ysin = sinf(rotation.y * MY_2PI_FLOAT);
+ const float ycos = cosf(rotation.y * MY_2PI_FLOAT);
- const float z2pi = rotation.z * MY_2PI_FLOAT;
- const float sc = sinf(z2pi);
- const float cc = cosf(z2pi);
+ const float zsin = sinf(rotation.z * MY_2PI_FLOAT);
+ const float zcos = cosf(rotation.z * MY_2PI_FLOAT);
// x
- matrix.x.x = (ca * cc) + (sc * sa * sb);
- matrix.y.x = sa * cb;
- matrix.z.x = (cc * sa * sb) - (ca * sc);
+ matrix.x.x = (xcos * zcos) + (zsin * xsin * ysin);
+ matrix.y.x = xsin * ycos;
+ matrix.z.x = (zcos * xsin * ysin) - (xcos * zsin);
// y
- matrix.x.y = (sc * ca * sb) - (sa * cc);
- matrix.y.y = ca * cb;
- matrix.z.y = (sa * sc) + (cc * ca * sb);
+ matrix.x.y = (zsin * xcos * ysin) - (xsin * zcos);
+ matrix.y.y = xcos * ycos;
+ matrix.z.y = (xsin * zsin) + (zcos * xcos * ysin);
// z
- matrix.x.z = cb * sc;
- matrix.y.z = -sb;
- matrix.z.z = cb * cc;
+ matrix.x.z = ycos * zsin;
+ matrix.y.z = -ysin;
+ matrix.z.z = ycos * zcos;
}
void initAboutScreen(void)
@@ -101,21 +100,29 @@
sinp1 = 0;
sinp2 = SINUS_PHASES/4; // cosine offset
logoAlpha16 = (65535 * LOGO_ALPHA_PERCENTAGE) / 100;
+ starShineAlpha16 = (65535 * STARSHINE_ALPHA_PERCENTAGE) / 100;
+ starAlpha16 = (65535 * STAR_ALPHA_PERCENTAGE) / 100;
}
-static void blendPixel(int32_t x, int32_t y, uint32_t r, uint32_t g, uint32_t b, uint16_t alpha)
+static uint32_t blendPixels(uint32_t pixelA, uint32_t pixelB, uint16_t alpha)
{- uint32_t *p = &video.frameBuffer[(y * SCREEN_W) + x];
+ const uint16_t invAlpha = alpha ^ 0xFFFF;
- const uint32_t srcPixel = *p;
+ const int32_t r = ((RGB32_R(pixelA) * invAlpha) + (RGB32_R(pixelB) * alpha)) >> 16;
+ const int32_t g = ((RGB32_G(pixelA) * invAlpha) + (RGB32_G(pixelB) * alpha)) >> 16;
+ const int32_t b = ((RGB32_B(pixelA) * invAlpha) + (RGB32_B(pixelB) * alpha)) >> 16;
+ return RGB32(r, g, b);
+}
- const uint32_t srcR = RGB32_R(srcPixel);
- const uint32_t srcG = RGB32_G(srcPixel);
- const uint32_t srcB = RGB32_B(srcPixel);
+static void blendPixelsXY(uint32_t x, uint32_t y, uint32_t pixelB_r, uint32_t pixelB_g, uint32_t pixelB_b, uint16_t alpha)
+{+ uint32_t *p = &video.frameBuffer[(y * SCREEN_W) + x];
+ const uint32_t pixelA = *p;
- r = ((srcR * (alpha ^ 65535)) + (r * alpha)) >> 16;
- g = ((srcG * (alpha ^ 65535)) + (g * alpha)) >> 16;
- b = ((srcB * (alpha ^ 65535)) + (b * alpha)) >> 16;
+ const uint16_t invAlpha = alpha ^ 0xFFFF;
+ const int32_t r = ((RGB32_R(pixelA) * invAlpha) + (pixelB_r * alpha)) >> 16;
+ const int32_t g = ((RGB32_G(pixelA) * invAlpha) + (pixelB_g * alpha)) >> 16;
+ const int32_t b = ((RGB32_B(pixelA) * invAlpha) + (pixelB_b * alpha)) >> 16;
*p = RGB32(r, g, b);
}
@@ -143,57 +150,47 @@
if (outX < ABOUT_SCREEN_X || outX >= ABOUT_SCREEN_X+ABOUT_SCREEN_W)
continue;
- int32_t d = (int32_t)(z * 256.0f);
- if (d > 255)
- d = 255;
- d ^= 255;
+ int32_t intensity255 = (int32_t)(z * 256.0f);
+ if (intensity255 > 255)
+ intensity255 = 255;
+ intensity255 ^= 255;
// add a tint of blue to the star pixel
- int32_t r = d - 79;
+ int32_t r = intensity255 - 79;
if (r < 0)
r = 0;
- int32_t g = d - 38;
+ int32_t g = intensity255 - 38;
if (g < 0)
g = 0;
- int32_t b = d + 64;
+ int32_t b = intensity255 + 64;
if (b > 255)
b = 255;
- // blend sides of star
+ // plot and blend sides of star (basic shine effect)
- const uint16_t sidesAlpha = 13000;
-
if (outX-1 >= ABOUT_SCREEN_X)
- blendPixel(outX-1, outY, r, g, b, sidesAlpha);
+ blendPixelsXY(outX-1, outY, r, g, b, starShineAlpha16);
if (outX+1 < ABOUT_SCREEN_X+ABOUT_SCREEN_W)
- blendPixel(outX+1, outY, r, g, b, sidesAlpha);
+ blendPixelsXY(outX+1, outY, r, g, b, starShineAlpha16);
if (outY-1 >= ABOUT_SCREEN_Y)
- blendPixel(outX, outY-1, r, g, b, sidesAlpha);
+ blendPixelsXY(outX, outY-1, r, g, b, starShineAlpha16);
if (outY+1 < ABOUT_SCREEN_Y+ABOUT_SCREEN_H)
- blendPixel(outX, outY+1, r, g, b, sidesAlpha);
+ blendPixelsXY(outX, outY+1, r, g, b, starShineAlpha16);
- // plot main star pixel
- blendPixel(outX, outY, r, g, b, 60000);
+ // plot center pixel
+ blendPixelsXY(outX, outY, r, g, b, starAlpha16);
}
}
-static uint32_t blendPixelAB(uint32_t pixelA, uint32_t pixelB, uint16_t alpha)
-{- const int32_t r = ((RGB32_R(pixelA) * (alpha ^ 65535)) + (RGB32_R(pixelB) * alpha)) >> 16;
- const int32_t g = ((RGB32_G(pixelA) * (alpha ^ 65535)) + (RGB32_G(pixelB) * alpha)) >> 16;
- const int32_t b = ((RGB32_B(pixelA) * (alpha ^ 65535)) + (RGB32_B(pixelB) * alpha)) >> 16;
- return RGB32(r, g, b);
-}
-
void renderAboutScreenFrame(void)
{- // remember when you couldn't do this per frame?
+ // remember the days when you couldn't afford to do this per frame?
clearRect(ABOUT_SCREEN_X, ABOUT_SCREEN_Y, ABOUT_SCREEN_W, ABOUT_SCREEN_H);
// 3D starfield
@@ -210,7 +207,7 @@
{for (int32_t x = 0; x < ABOUT_SCREEN_W; x++)
{- int32_t srcX = (x - ((ABOUT_SCREEN_W-ABOUT_LOGO_W)/2)) + (sin16[(sinp1+x) & (SINUS_PHASES-1)] >> 10);
+ int32_t srcX = (x - ((ABOUT_SCREEN_W-ABOUT_LOGO_W)/2)) + (sin16[(sinp1+x) & (SINUS_PHASES-1)] >> 10);
int32_t srcY = (y - ((ABOUT_SCREEN_H-ABOUT_LOGO_H)/2)+20) + (sin16[(sinp2+y+x+x) & (SINUS_PHASES-1)] >> 11);
if ((uint32_t)srcX < ABOUT_LOGO_W && (uint32_t)srcY < ABOUT_LOGO_H)
@@ -217,7 +214,7 @@
{const uint32_t logoPixel = bmp.ft2AboutLogo[(srcY * ABOUT_LOGO_W) + srcX];
if (logoPixel != 0x00FF00) // transparency
- dstPtr[x] = blendPixelAB(dstPtr[x], logoPixel, logoAlpha16);
+ dstPtr[x] = blendPixels(dstPtr[x], logoPixel, logoAlpha16);
}
}
}
--- a/src/mixer/ft2_mix_macros.h
+++ b/src/mixer/ft2_mix_macros.h
@@ -103,8 +103,8 @@
#define LINEAR_INTERPOLATION(s, f, scale) \
{ \const int32_t frac = (uint32_t)(f) >> 1; /* uint32 -> int32 range, faster int->float conv. (x86/x86_64) */ \
- const float fFrac = frac * (1.0f / (MIXER_FRAC_SCALE/2)); /* 0.0f .. 0.9999999f */ \
- fSample = ((s[0] + (s[1]-s[0]) * fFrac)) * (1.0f / scale); \
+ const float fFrac = (int32_t)frac * (1.0f / (MIXER_FRAC_SCALE/2)); /* 0.0f .. 0.9999999f */ \
+ fSample = (s[0] + ((s[1] - s[0]) * fFrac)) * (1.0f / scale); \
}
#define RENDER_8BIT_SMP_LINTRP \
--
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