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split tiv_lib.h/.cpp out of tiv.cpp, adressing issue #52
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@stefanhaustein
stefanhaustein committed Feb 14, 2024
1 parent 8c9ca72 commit b783c67
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Showing 4 changed files with 457 additions and 352 deletions.
8 changes: 5 additions & 3 deletions src/Makefile
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Original file line number Diff line number Diff line change
@@ -1,7 +1,7 @@
PROGNAME = tiv

OBJECTS = tiv.o

OBJECTS = tiv.o tiv_lib.o
CXX ?= g++
CXXFLAGS ?= -O2 -fpermissive
INSTALL ?= install
Expand All @@ -17,7 +17,9 @@ override LDFLAGS += -pthread

all: $(PROGNAME)

tiv.o: CImg.h
tiv_lib.o: tiv_lib.h

tiv.o: CImg.h tiv_lib.h

$(PROGNAME): $(OBJECTS)
$(CXX) $(LDFLAGS) $^ -o $@ $(LOADLIBES) $(LDLIBS)
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351 changes: 2 additions & 349 deletions src/tiv.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -41,6 +41,8 @@
#include <string>
#include <vector>

#include "tiv_lib.h"

// This #define tells CImg that we use the library without any display options
// -- just for loading images.
#define cimg_display 0
Expand All @@ -65,355 +67,6 @@
#define EXITCODE_DATA_FORMAT_ERROR 65
#define EXITCODE_NO_INPUT_ERROR 66

// Implementation of flag representation for flags in the main() method
constexpr int FLAG_FG = 1;
constexpr int FLAG_BG = 2;
constexpr int FLAG_MODE_256 = 4; // Limit colors to 256-color mode
constexpr int FLAG_24BIT = 8; // 24-bit color mode
constexpr int FLAG_NOOPT = 16; // Only use the same half-block character
constexpr int FLAG_TELETEXT = 32; // Use teletext characters

// Color saturation value steps from 0 to 255
constexpr int COLOR_STEP_COUNT = 6;
constexpr int COLOR_STEPS[COLOR_STEP_COUNT] = {0, 0x5f, 0x87, 0xaf, 0xd7, 0xff};

// Grayscale saturation value steps from 0 to 255
constexpr int GRAYSCALE_STEP_COUNT = 24;
constexpr int GRAYSCALE_STEPS[GRAYSCALE_STEP_COUNT] = {
0x08, 0x12, 0x1c, 0x26, 0x30, 0x3a, 0x44, 0x4e, 0x58, 0x62, 0x6c, 0x76,
0x80, 0x8a, 0x94, 0x9e, 0xa8, 0xb2, 0xbc, 0xc6, 0xd0, 0xda, 0xe4, 0xee};

// An interleaved map of 4x8 bit character bitmaps (each hex digit represents a
// row) to the corresponding unicode character code point.
constexpr unsigned int BITMAPS[] = {
0x00000000, 0x00a0,

// Block graphics
// 0xffff0000, 0x2580, // upper 1/2; redundant with inverse lower 1/2

0x0000000f, 0x2581, // lower 1/8
0x000000ff, 0x2582, // lower 1/4
0x00000fff, 0x2583, 0x0000ffff, 0x2584, // lower 1/2
0x000fffff, 0x2585, 0x00ffffff, 0x2586, // lower 3/4
0x0fffffff, 0x2587,
// 0xffffffff, 0x2588, // full; redundant with inverse space

0xeeeeeeee, 0x258a, // left 3/4
0xcccccccc, 0x258c, // left 1/2
0x88888888, 0x258e, // left 1/4

0x0000cccc, 0x2596, // quadrant lower left
0x00003333, 0x2597, // quadrant lower right
0xcccc0000,
0x2598, // quadrant upper left
// 0xccccffff, 0x2599, // 3/4 redundant with inverse 1/4
0xcccc3333, 0x259a, // diagonal 1/2
// 0xffffcccc, 0x259b, // 3/4 redundant
// 0xffff3333, 0x259c, // 3/4 redundant
0x33330000, 0x259d, // quadrant upper right
// 0x3333cccc, 0x259e, // 3/4 redundant
// 0x3333ffff, 0x259f, // 3/4 redundant

// Line drawing subset: no double lines, no complex light lines

0x000ff000, 0x2501, // Heavy horizontal
0x66666666, 0x2503, // Heavy vertical

0x00077666, 0x250f, // Heavy down and right
0x000ee666, 0x2513, // Heavy down and left
0x66677000, 0x2517, // Heavy up and right
0x666ee000, 0x251b, // Heavy up and left

0x66677666, 0x2523, // Heavy vertical and right
0x666ee666, 0x252b, // Heavy vertical and left
0x000ff666, 0x2533, // Heavy down and horizontal
0x666ff000, 0x253b, // Heavy up and horizontal
0x666ff666, 0x254b, // Heavy cross

0x000cc000, 0x2578, // Bold horizontal left
0x00066000, 0x2579, // Bold horizontal up
0x00033000, 0x257a, // Bold horizontal right
0x00066000, 0x257b, // Bold horizontal down

0x06600660, 0x254f, // Heavy double dash vertical

0x000f0000, 0x2500, // Light horizontal
0x0000f000, 0x2500, //
0x44444444, 0x2502, // Light vertical
0x22222222, 0x2502,

0x000e0000, 0x2574, // light left
0x0000e000, 0x2574, // light left
0x44440000, 0x2575, // light up
0x22220000, 0x2575, // light up
0x00030000, 0x2576, // light right
0x00003000, 0x2576, // light right
0x00004444, 0x2577, // light down
0x00002222, 0x2577, // light down

// Misc technical

0x44444444, 0x23a2, // [ extension
0x22222222, 0x23a5, // ] extension

0x0f000000, 0x23ba, // Horizontal scanline 1
0x00f00000, 0x23bb, // Horizontal scanline 3
0x00000f00, 0x23bc, // Horizontal scanline 7
0x000000f0, 0x23bd, // Horizontal scanline 9

// Geometrical shapes. Tricky because some of them are too wide.

// 0x00ffff00, 0x25fe, // Black medium small square
0x00066000, 0x25aa, // Black small square

// 0x11224488, 0x2571, // diagonals
// 0x88442211, 0x2572,
// 0x99666699, 0x2573,
// 0x000137f0, 0x25e2, // Triangles
// 0x0008cef0, 0x25e3,
// 0x000fec80, 0x25e4,
// 0x000f7310, 0x25e5,

0, 0, // End marker for "regular" characters

// Teletext / legacy graphics 3x2 block character codes.
// Using a 3-2-3 pattern consistently, perhaps we should create automatic
// variations....

0xccc00000, 0xfb00, 0x33300000, 0xfb01, 0xfff00000, 0xfb02, 0x000cc000,
0xfb03, 0xccccc000, 0xfb04, 0x333cc000, 0xfb05, 0xfffcc000, 0xfb06,
0x00033000, 0xfb07, 0xccc33000, 0xfb08, 0x33333000, 0xfb09, 0xfff33000,
0xfb0a, 0x000ff000, 0xfb0b, 0xcccff000, 0xfb0c, 0x333ff000, 0xfb0d,
0xfffff000, 0xfb0e, 0x00000ccc, 0xfb0f,

0xccc00ccc, 0xfb10, 0x33300ccc, 0xfb11, 0xfff00ccc, 0xfb12, 0x000ccccc,
0xfb13, 0x333ccccc, 0xfb14, 0xfffccccc, 0xfb15, 0x00033ccc, 0xfb16,
0xccc33ccc, 0xfb17, 0x33333ccc, 0xfb18, 0xfff33ccc, 0xfb19, 0x000ffccc,
0xfb1a, 0xcccffccc, 0xfb1b, 0x333ffccc, 0xfb1c, 0xfffffccc, 0xfb1d,
0x00000333, 0xfb1e, 0xccc00333, 0xfb1f,

0x33300333, 0x1b20, 0xfff00333, 0x1b21, 0x000cc333, 0x1b22, 0xccccc333,
0x1b23, 0x333cc333, 0x1b24, 0xfffcc333, 0x1b25, 0x00033333, 0x1b26,
0xccc33333, 0x1b27, 0xfff33333, 0x1b28, 0x000ff333, 0x1b29, 0xcccff333,
0x1b2a, 0x333ff333, 0x1b2b, 0xfffff333, 0x1b2c, 0x00000fff, 0x1b2d,
0xccc00fff, 0x1b2e, 0x33300fff, 0x1b2f,

0xfff00fff, 0x1b30, 0x000ccfff, 0x1b31, 0xcccccfff, 0x1b32, 0x333ccfff,
0x1b33, 0xfffccfff, 0x1b34, 0x00033fff, 0x1b35, 0xccc33fff, 0x1b36,
0x33333fff, 0x1b37, 0xfff33fff, 0x1b38, 0x000fffff, 0x1b39, 0xcccfffff,
0x1b3a, 0x333fffff, 0x1b3b,

0, 1 // End marker for extended TELETEXT mode.
};

/**
* @brief Struct to represent a character to be drawn.
* @param fgColor RGB
* @param bgColor RGB
* @param codePoint The code point of the character to be drawn.
*/
struct CharData {
std::array<int, 3> fgColor = std::array<int, 3>{0, 0, 0};
std::array<int, 3> bgColor = std::array<int, 3>{0, 0, 0};
int codePoint;
};

typedef std::function<unsigned char(int, int, int)> GetPixelFunction;

// Return a CharData struct with the given code point and corresponding averag
// fg and bg colors.
CharData createCharData(GetPixelFunction get_pixel, int x0, int y0,
int codepoint, int pattern) {
CharData result;
result.codePoint = codepoint;
int fg_count = 0;
int bg_count = 0;
unsigned int mask = 0x80000000;

for (int y = 0; y < 8; y++) {
for (int x = 0; x < 4; x++) {
int *avg;
if (pattern & mask) {
avg = result.fgColor.data();
fg_count++;
} else {
avg = result.bgColor.data();
bg_count++;
}
for (int i = 0; i < 3; i++) {
avg[i] += get_pixel(x0 + x, y0 + y, i);
}
mask = mask >> 1;
}
}

// Calculate the average color value for each bucket
for (int i = 0; i < 3; i++) {
if (bg_count != 0) {
result.bgColor[i] /= bg_count;
}
if (fg_count != 0) {
result.fgColor[i] /= fg_count;
}
}
return result;
}

/**
* @brief Find the best character and colors
* for a 4x8 part of the image at the given position
*
* @param image
* @param x0
* @param y0
* @param flags
* @return CharData
*/
CharData findCharData(GetPixelFunction get_pixel, int x0, int y0,
const int &flags) {
int min[3] = {255, 255, 255};
int max[3] = {0};
std::map<long, int> count_per_color;

// Determine the minimum and maximum value for each color channel
for (int y = 0; y < 8; y++) {
for (int x = 0; x < 4; x++) {
long color = 0;
for (int i = 0; i < 3; i++) {
int d = get_pixel(x0 + x, y0 + y, i);
min[i] = std::min(min[i], d);
max[i] = std::max(max[i], d);
color = (color << 8) | d;
}
count_per_color[color]++;
}
}

std::multimap<int, long> color_per_count;
for (auto i = count_per_color.begin(); i != count_per_color.end(); ++i) {
color_per_count.insert(std::pair<int, long>(i->second, i->first));
}

auto iter = color_per_count.rbegin();
int count2 = iter->first;
long max_count_color_1 = iter->second;
long max_count_color_2 = max_count_color_1;
if ((++iter) != color_per_count.rend()) {
count2 += iter->first;
max_count_color_2 = iter->second;
}

unsigned int bits = 0;
bool direct = count2 > (8 * 4) / 2;

if (direct) {
for (int y = 0; y < 8; y++) {
for (int x = 0; x < 4; x++) {
bits = bits << 1;
int d1 = 0;
int d2 = 0;
for (int i = 0; i < 3; i++) {
int shift = 16 - 8 * i;
int c1 = (max_count_color_1 >> shift) & 255;
int c2 = (max_count_color_2 >> shift) & 255;
int c = get_pixel(x0 + x, y0 + y, i);
d1 += (c1 - c) * (c1 - c);
d2 += (c2 - c) * (c2 - c);
}
if (d1 > d2) {
bits |= 1;
}
}
}
} else {
// Determine the color channel with the greatest range.
int splitIndex = 0;
int bestSplit = 0;
for (int i = 0; i < 3; i++) {
if (max[i] - min[i] > bestSplit) {
bestSplit = max[i] - min[i];
splitIndex = i;
}
}

// We just split at the middle of the interval instead of computing the
// median.
int splitValue = min[splitIndex] + bestSplit / 2;

// Compute a bitmap using the given split and sum the color values for
// both buckets.
for (int y = 0; y < 8; y++) {
for (int x = 0; x < 4; x++) {
bits = bits << 1;
if (get_pixel(x0 + x, y0 + y, splitIndex) > splitValue) {
bits |= 1;
}
}
}
}

// Find the best bitmap match by counting the bits that don't match,
// including the inverted bitmaps.
int best_diff = 8;
unsigned int best_pattern = 0x0000ffff;
int codepoint = 0x2584;
bool inverted = false;
unsigned int end_marker = flags & FLAG_TELETEXT ? 1 : 0;
for (int i = 0; BITMAPS[i + 1] != end_marker; i += 2) {
// Skip all end markers
if (BITMAPS[i + 1] < 32) {
continue;
}
unsigned int pattern = BITMAPS[i];
for (int j = 0; j < 2; j++) {
int diff = (std::bitset<32>(pattern ^ bits)).count();
if (diff < best_diff) {
best_pattern = BITMAPS[i]; // pattern might be inverted.
codepoint = BITMAPS[i + 1];
best_diff = diff;
inverted = best_pattern != pattern;
}
pattern = ~pattern;
}
}

if (direct) {
CharData result;
if (inverted) {
long tmp = max_count_color_1;
max_count_color_1 = max_count_color_2;
max_count_color_2 = tmp;
}
for (int i = 0; i < 3; i++) {
int shift = 16 - 8 * i;
result.fgColor[i] = (max_count_color_2 >> shift) & 255;
result.bgColor[i] = (max_count_color_1 >> shift) & 255;
result.codePoint = codepoint;
}
return result;
}
return createCharData(get_pixel, x0, y0, codepoint, best_pattern);
}

int clamp_byte(int value) {
return value < 0 ? 0 : (value > 255 ? 255 : value);
}

double sqr(double n) { return n * n; }

int best_index(int value, const int STEPS[], int count) {
int best_diff = std::abs(STEPS[0] - value);
int result = 0;
for (int i = 1; i < count; i++) {
int diff = std::abs(STEPS[i] - value);
if (diff < best_diff) {
result = i;
best_diff = diff;
}
}
return result;
}

void printTermColor(const int &flags, int r, int g, int b) {
r = clamp_byte(r);
g = clamp_byte(g);
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