From 524db0cf19648e3c7c78d3e73103b7a0bdcd6bfc Mon Sep 17 00:00:00 2001 From: Vito Caputo Date: Wed, 18 Jan 2017 17:14:52 -0800 Subject: *: move source into src/ subdir Restoring some organizational sanity since adopting autotools. --- src/modules/roto/Makefile.am | 4 + src/modules/roto/roto.c | 305 +++++++++++++++++++++++++++++++++++++++++++ src/modules/roto/roto.h | 9 ++ 3 files changed, 318 insertions(+) create mode 100644 src/modules/roto/Makefile.am create mode 100644 src/modules/roto/roto.c create mode 100644 src/modules/roto/roto.h (limited to 'src/modules/roto') diff --git a/src/modules/roto/Makefile.am b/src/modules/roto/Makefile.am new file mode 100644 index 0000000..08d8522 --- /dev/null +++ b/src/modules/roto/Makefile.am @@ -0,0 +1,4 @@ +noinst_LIBRARIES = libroto.a +libroto_a_SOURCES = roto.c roto.h +libroto_a_CFLAGS = @ROTOTILLER_CFLAGS@ +libroto_a_CPPFLAGS = @ROTOTILLER_CFLAGS@ -I../../ diff --git a/src/modules/roto/roto.c b/src/modules/roto/roto.c new file mode 100644 index 0000000..d789f85 --- /dev/null +++ b/src/modules/roto/roto.c @@ -0,0 +1,305 @@ +#include +#include +#include + +#include "fb.h" +#include "rototiller.h" + +/* Copyright (C) 2016 Vito Caputo */ + +/* Some defines for the fixed-point stuff in render(). */ +#define FIXED_TRIG_LUT_SIZE 4096 /* size of the cos/sin look-up tables */ +#define FIXED_BITS 11 /* fractional bits */ +#define FIXED_EXP (1 << FIXED_BITS) /* 2^FIXED_BITS */ +#define FIXED_MASK (FIXED_EXP - 1) /* fractional part mask */ +#define FIXED_COS(_rad) costab[(_rad) % FIXED_TRIG_LUT_SIZE] +#define FIXED_SIN(_rad) sintab[(_rad) % FIXED_TRIG_LUT_SIZE] +#define FIXED_MULT(_a, _b) (((_a) * (_b)) >> FIXED_BITS) +#define FIXED_NEW(_i) ((_i) << FIXED_BITS) +#define FIXED_TO_INT(_f) ((_f) >> FIXED_BITS) + +typedef struct color_t { + int r, g, b; +} color_t; + + +/* linearly interpolate between two colors, alpha is fixed-point value 0-FIXED_EXP. */ +static inline color_t lerp_color(color_t *a, color_t *b, int alpha) +{ + /* TODO: This could be done without multiplies with a bit of effort, + * maybe a simple table mapping integer color deltas to shift values + * for shifting alpha which then gets simply added? A table may not even + * be necessary, use the order of the delta to derive how much to shift + * alpha? + */ + color_t c = { + .r = a->r + FIXED_MULT(alpha, b->r - a->r), + .g = a->g + FIXED_MULT(alpha, b->g - a->g), + .b = a->b + FIXED_MULT(alpha, b->b - a->b), + }; + + return c; +} + + +/* Return the bilinearly interpolated color palette[texture[ty][tx]] (Anti-Aliasing) */ +/* tx, ty are fixed-point for fractions, palette colors are also in fixed-point format. */ +static uint32_t bilerp_color(uint8_t texture[256][256], color_t *palette, int tx, int ty) +{ + uint8_t itx = FIXED_TO_INT(tx), ity = FIXED_TO_INT(ty); + color_t n_color, s_color, color; + int x_alpha, y_alpha; + uint8_t nw, ne, sw, se; + + /* We need the 4 texels constituting a 2x2 square pattern to interpolate. + * A point tx,ty can only intersect one texel; one corner of the 2x2 square. + * Where relative to the corner's center the intersection occurs determines which corner has been intersected, + * and the other corner texels may then be addressed relative to that corner. + * Alpha values must also be determined for both axis, these values describe the position between + * the 2x2 texel centers the intersection occurred, aka the weight or bias. + * Once the two alpha values are known, linear interpolation between the texel colors is trivial. + */ + + if ((ty & FIXED_MASK) > (FIXED_EXP >> 1)) { + y_alpha = ty & (FIXED_MASK >> 1); + + if ((tx & (FIXED_MASK)) > (FIXED_EXP >> 1)) { + nw = texture[ity][itx]; + ne = texture[ity][(uint8_t)(itx + 1)]; + sw = texture[(uint8_t)(ity + 1)][itx]; + se = texture[(uint8_t)(ity + 1)][(uint8_t)(itx + 1)]; + + x_alpha = tx & (FIXED_MASK >> 1); + } else { + ne = texture[ity][itx]; + nw = texture[ity][(uint8_t)(itx - 1)]; + se = texture[(uint8_t)(ity + 1)][itx]; + sw = texture[(uint8_t)(ity + 1)][(uint8_t)(itx - 1)]; + + x_alpha = (FIXED_EXP >> 1) + (tx & (FIXED_MASK >> 1)); + } + } else { + y_alpha = (FIXED_EXP >> 1) + (ty & (FIXED_MASK >> 1)); + + if ((tx & (FIXED_MASK)) > (FIXED_EXP >> 1)) { + sw = texture[ity][itx]; + se = texture[ity][(uint8_t)(itx + 1)]; + nw = texture[(uint8_t)(ity - 1)][itx]; + ne = texture[(uint8_t)(ity - 1)][(uint8_t)(itx + 1)]; + + x_alpha = tx & (FIXED_MASK >> 1); + } else { + se = texture[ity][itx]; + sw = texture[ity][(uint8_t)(itx - 1)]; + ne = texture[(uint8_t)(ity - 1)][itx]; + nw = texture[(uint8_t)(ity - 1)][(uint8_t)(itx - 1)]; + + x_alpha = (FIXED_EXP >> 1) + (tx & (FIXED_MASK >> 1)); + } + } + + /* Skip interpolation of same colors, a substantial optimization with plain textures like the checker pattern */ + if (nw == ne) { + if (ne == sw && sw == se) { + return (FIXED_TO_INT(palette[sw].r) << 16) | (FIXED_TO_INT(palette[sw].g) << 8) | FIXED_TO_INT(palette[sw].b); + } + n_color = palette[nw]; + } else { + n_color = lerp_color(&palette[nw], &palette[ne], x_alpha); + } + + if (sw == se) { + s_color = palette[sw]; + } else { + s_color = lerp_color(&palette[sw], &palette[se], x_alpha); + } + + color = lerp_color(&n_color, &s_color, y_alpha); + + return (FIXED_TO_INT(color.r) << 16) | (FIXED_TO_INT(color.g) << 8) | FIXED_TO_INT(color.b); +} + + +static void init_roto(uint8_t texture[256][256], int32_t *costab, int32_t *sintab) +{ + int x, y, i; + + /* Generate simple checker pattern texture, nothing clever, feel free to play! */ + /* If you modify texture on every frame instead of only @ initialization you can + * produce some neat output. These values are indexed into palette[] below. */ + for (y = 0; y < 128; y++) { + for (x = 0; x < 128; x++) + texture[y][x] = 1; + for (; x < 256; x++) + texture[y][x] = 0; + } + for (; y < 256; y++) { + for (x = 0; x < 128; x++) + texture[y][x] = 0; + for (; x < 256; x++) + texture[y][x] = 1; + } + + /* Generate fixed-point cos & sin LUTs. */ + for (i = 0; i < FIXED_TRIG_LUT_SIZE; i++) { + costab[i] = ((cos((double)2*M_PI*i/FIXED_TRIG_LUT_SIZE))*FIXED_EXP); + sintab[i] = ((sin((double)2*M_PI*i/FIXED_TRIG_LUT_SIZE))*FIXED_EXP); + } +} + + +/* Draw a rotating checkered 256x256 texture into fragment. (32-bit version) */ +static void roto32(fb_fragment_t *fragment) +{ + static int32_t costab[FIXED_TRIG_LUT_SIZE], sintab[FIXED_TRIG_LUT_SIZE]; + static uint8_t texture[256][256]; + static int initialized; + static color_t palette[2]; + static unsigned r, rr; + + int y_cos_r, y_sin_r, x_cos_r, x_sin_r, x_cos_r_init, x_sin_r_init, cos_r, sin_r; + int x, y, stride = fragment->stride / 4, width = fragment->width, height = fragment->height; + uint32_t *buf = fragment->buf; + + if (!initialized) { + initialized = 1; + + init_roto(texture, costab, sintab); + } + + /* This is all done using fixed-point in the hopes of being faster, and yes assumptions + * are being made WRT the overflow of tx/ty as well, only tested on x86_64. */ + cos_r = FIXED_COS(r); + sin_r = FIXED_SIN(r); + + /* Vary the colors, this is just a mashup of sinusoidal rgb values. */ + palette[0].r = (FIXED_MULT(FIXED_COS(rr), FIXED_NEW(127)) + FIXED_NEW(128)); + palette[0].g = (FIXED_MULT(FIXED_SIN(rr / 2), FIXED_NEW(127)) + FIXED_NEW(128)); + palette[0].b = (FIXED_MULT(FIXED_COS(rr / 3), FIXED_NEW(127)) + FIXED_NEW(128)); + + palette[1].r = (FIXED_MULT(FIXED_SIN(rr / 2), FIXED_NEW(127)) + FIXED_NEW(128)); + palette[1].g = (FIXED_MULT(FIXED_COS(rr / 2), FIXED_NEW(127)) + FIXED_NEW(128)); + palette[1].b = (FIXED_MULT(FIXED_SIN(rr), FIXED_NEW(127)) + FIXED_NEW(128)); + + /* The dimensions are cut in half and negated to center the rotation. */ + /* The [xy]_{sin,cos}_r variables are accumulators to replace multiplication with addition. */ + x_cos_r_init = FIXED_MULT(-FIXED_NEW((width / 2)), cos_r); + x_sin_r_init = FIXED_MULT(-FIXED_NEW((width / 2)), sin_r); + + y_cos_r = FIXED_MULT(-FIXED_NEW((height / 2)), cos_r); + y_sin_r = FIXED_MULT(-FIXED_NEW((height / 2)), sin_r); + + for (y = 0; y < height; y++) { + + x_cos_r = x_cos_r_init; + x_sin_r = x_sin_r_init; + + for (x = 0; x < width; x++, buf++) { + *buf = bilerp_color(texture, palette, x_sin_r - y_cos_r, y_sin_r + x_cos_r); + + x_cos_r += cos_r; + x_sin_r += sin_r; + } + + buf += stride; + y_cos_r += cos_r; + y_sin_r += sin_r; + } + + // This governs the rotation and color cycle. + r += FIXED_TO_INT(FIXED_MULT(FIXED_SIN(rr), FIXED_NEW(16))); + rr += 2; +} + + +/* Draw a rotating checkered 256x256 texture into fragment. (64-bit version) */ +static void roto64(fb_fragment_t *fragment) +{ + static int32_t costab[FIXED_TRIG_LUT_SIZE], sintab[FIXED_TRIG_LUT_SIZE]; + static uint8_t texture[256][256]; + static int initialized; + static color_t palette[2]; + static unsigned r, rr; + + int y_cos_r, y_sin_r, x_cos_r, x_sin_r, x_cos_r_init, x_sin_r_init, cos_r, sin_r; + int x, y, stride = fragment->stride / 8, width = fragment->width, height = fragment->height; + uint64_t *buf = (uint64_t *)fragment->buf; + + if (!initialized) { + initialized = 1; + + init_roto(texture, costab, sintab); + } + + /* This is all done using fixed-point in the hopes of being faster, and yes assumptions + * are being made WRT the overflow of tx/ty as well, only tested on x86_64. */ + cos_r = FIXED_COS(r); + sin_r = FIXED_SIN(r); + + /* Vary the colors, this is just a mashup of sinusoidal rgb values. */ + palette[0].r = (FIXED_MULT(FIXED_COS(rr), FIXED_NEW(127)) + FIXED_NEW(128)); + palette[0].g = (FIXED_MULT(FIXED_SIN(rr / 2), FIXED_NEW(127)) + FIXED_NEW(128)); + palette[0].b = (FIXED_MULT(FIXED_COS(rr / 3), FIXED_NEW(127)) + FIXED_NEW(128)); + + palette[1].r = (FIXED_MULT(FIXED_SIN(rr / 2), FIXED_NEW(127)) + FIXED_NEW(128)); + palette[1].g = (FIXED_MULT(FIXED_COS(rr / 2), FIXED_NEW(127)) + FIXED_NEW(128)); + palette[1].b = (FIXED_MULT(FIXED_SIN(rr), FIXED_NEW(127)) + FIXED_NEW(128)); + + /* The dimensions are cut in half and negated to center the rotation. */ + /* The [xy]_{sin,cos}_r variables are accumulators to replace multiplication with addition. */ + x_cos_r_init = FIXED_MULT(-FIXED_NEW((width / 2)), cos_r); + x_sin_r_init = FIXED_MULT(-FIXED_NEW((width / 2)), sin_r); + + y_cos_r = FIXED_MULT(-FIXED_NEW((height / 2)), cos_r); + y_sin_r = FIXED_MULT(-FIXED_NEW((height / 2)), sin_r); + + width /= 2; /* Since we're processing 64-bit words (2 pixels) at a time */ + + for (y = 0; y < height; y++) { + + x_cos_r = x_cos_r_init; + x_sin_r = x_sin_r_init; + + for (x = 0; x < width; x++, buf++) { + uint64_t p; + + p = bilerp_color(texture, palette, x_sin_r - y_cos_r, y_sin_r + x_cos_r); + + x_cos_r += cos_r; + x_sin_r += sin_r; + + p |= (uint64_t)(bilerp_color(texture, palette, x_sin_r - y_cos_r, y_sin_r + x_cos_r)) << 32; + + *buf = p; + + x_cos_r += cos_r; + x_sin_r += sin_r; + } + + buf += stride; + y_cos_r += cos_r; + y_sin_r += sin_r; + } + + // This governs the rotation and color cycle. + r += FIXED_TO_INT(FIXED_MULT(FIXED_SIN(rr), FIXED_NEW(16))); + rr += 2; +} + + +rototiller_renderer_t roto32_renderer = { + .render = roto32, + .name = "roto32", + .description = "Anti-aliased tiled texture rotation (32-bit)", + .author = "Vito Caputo ", + .license = "GPLv2", +}; + + +rototiller_renderer_t roto64_renderer = { + .render = roto64, + .name = "roto64", + .description = "Anti-aliased tiled texture rotation (64-bit)", + .author = "Vito Caputo ", + .license = "GPLv2", +}; diff --git a/src/modules/roto/roto.h b/src/modules/roto/roto.h new file mode 100644 index 0000000..84a66a9 --- /dev/null +++ b/src/modules/roto/roto.h @@ -0,0 +1,9 @@ +#ifndef _ROTO_H +#define _ROTO_H + +#include "fb.h" + +void roto64(fb_fragment_t *fragment); +void roto32(fb_fragment_t *fragment); + +#endif -- cgit v1.2.1