387 lines
12 KiB
C++
387 lines
12 KiB
C++
/* Example program that links against the waymini library.
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* No external dependencies beyond waymini itself and the C standard library.
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*/
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#include "waymini.h"
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#include <stdint.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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// this should be handled elsewhere, eventually, maybe, probably
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static void on_key(void *user, uint32_t keycode, uint32_t state) {
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(void)user;
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const char *label = state ? "down" : "up ";
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printf("key %s: %u\n", label, keycode);
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fflush(stdout);
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}
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namespace UwU {
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// Color datatype returns individual channel values from rgba hexcode
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struct Color {
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Color(uint32_t hex) {
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this->a = hex & 0x000000ff;
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this->b = (hex & 0x0000ff00) >> 8;
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this->g = (hex & 0x00ff0000) >> 16;
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this->r = (hex & 0xff000000) >> 24;
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}
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Color() {}
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uint8_t r;
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uint8_t g;
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uint8_t b;
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uint8_t a;
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};
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// Coord2 datatype for xy coordinates, from top-left of surface
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struct Coord2 {
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Coord2(uint32_t x, uint32_t y) {
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this->x = x;
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this->y = y;
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}
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Coord2() {}
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uint32_t x;
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uint32_t y;
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};
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// trapezoid datatype (horizontally constrained)
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struct Trapezoid {
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Trapezoid(uint16_t y0, uint16_t y1, uint16_t xl0, uint16_t xl1, uint16_t xr0, uint16_t xr1) {
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this->y0 = y0;
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this->y1 = y1;
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this->xl0 = xl0;
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this->xl1 = xl1;
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this->xr0 = xr0;
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this->xr1 = xr1;
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}
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Trapezoid() {}
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uint16_t y0;
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uint16_t y1;
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uint16_t xl0;
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uint16_t xl1;
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uint16_t xr0;
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uint16_t xr1;
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};
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class Draw {
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private:
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uint8_t lerp8(uint8_t a, uint8_t b, uint8_t t) {
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uint16_t product = (a * (255 - t)) + (b * t);
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return product / 255;
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}
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Color lerpColor(Color a, Color b, uint8_t t) {
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Color mixed = Color();
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mixed.r = this->lerp8(a.r, b.r, t);
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mixed.g = this->lerp8(a.g, b.g, t);
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mixed.b = this->lerp8(a.b, b.b, t);
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mixed.a = this->lerp8(a.a, b.a, t); // maybe the alpha channel should be handled differently?
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return mixed;
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}
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void putPixel(uint32_t x, uint32_t y, uint8_t r, uint8_t g, uint8_t b, uint8_t a = 0xff) {
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size_t i = (size_t)y * waymini_get_stride(this->wm) + (size_t)x * 4;
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uint8_t b0 = this->pixels[i + 0];
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uint8_t g0 = this->pixels[i + 1];
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uint8_t r0 = this->pixels[i + 2];
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b = lerp8(b0, b, a);
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g = lerp8(g0, g, a);
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r = lerp8(r0, r, a);
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this->pixels[i + 0] = b; // B
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this->pixels[i + 1] = g; // G
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this->pixels[i + 2] = r; // R
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this->pixels[i + 3] = 0xff; // A
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}
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void bresenhamLow(int16_t y0, uint16_t x1, int16_t y1, int16_t* LUT) {
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int16_t dx = int16_t(x1);
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int16_t dy = y1 - y0;
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int16_t yi = 1;
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if (dy < 0) {
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yi = -1;
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dy = -dy;
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}
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int16_t d = (2 * dy) - dx;
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int16_t y = y0;
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for (uint16_t x = 0; x <= x1; x++) {
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LUT[x] = y;
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if (d > 0) {
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y += yi;
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d += (2 * (dy - dx));
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} else {
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d += (2 * dy);
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}
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}
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return;
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}
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void bresenhamHigh(uint16_t x0, int16_t y0, uint16_t x1, int16_t y1, int16_t* LUT) {
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int16_t dx = (int16_t)x1 - (int16_t)x0;
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int16_t dy = y1 - y0;
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int16_t xi = 1;
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if (dx < 0) {
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xi = -1;
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dx = -dx;
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}
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int16_t d = (2 * dx) - dy;
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int16_t x = (int16_t)x0;
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for (int16_t y = y0; y <= y1; y++) {
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LUT[x] = y;
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if (d > 0) {
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x += xi;
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d += (2 * (dx - dy));
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} else {
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d += (2 * dx);
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}
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}
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return;
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}
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void bresenham(int16_t y0, uint16_t x1, int16_t y1, int16_t* LUT) {
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int16_t dy = y1 - y0;
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if (dy == 0) {
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// catch hline condition
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for (uint16_t i = 0; i <= x1; i++) {
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LUT[i] = y0;
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}
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return;
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}
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if (abs(y1 - y0) <= x1) {
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bresenhamLow(y0, x1, y1, LUT);
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} else {
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if (y0 > y1) {
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bresenhamHigh(x1, y1, 0, y0, LUT);
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} else {
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bresenhamHigh(0, y0, x1, y1, LUT);
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}
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}
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return;
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}
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// plot lines if m <= 1
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void lineLow(int32_t x0, int32_t y0, int32_t x1, int32_t y1, Color color) {
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int32_t dx = x1 - x0;
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int32_t dy = y1 - y0;
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int32_t yi = 1;
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if (dy < 0) {
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yi = -1;
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dy = -dy;
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}
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int32_t d = (2 * dy) - dx;
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int32_t y = y0;
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for (int32_t x = x0; x < x1; x++) {
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putPixel(x, y, color.r, color.g, color.b, color.a);
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if (d > 0) {
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y += yi;
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d += (2 * (dy - dx));
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} else {
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d += (2 * dy);
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}
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}
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return;
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}
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// plot lines if m >1
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void lineHigh(int32_t x0, int32_t y0, int32_t x1, int32_t y1, Color color) {
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int32_t dx = x1 - x0;
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int32_t dy = y1 - y0;
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int32_t xi = 1;
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if (dx < 0) {
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xi = -1;
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dx = -dx;
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}
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int32_t d = (2 * dx) - dy;
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int32_t x = x0;
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for (int32_t y = y0; y < y1; y++) {
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putPixel(x, y, color.r, color.g, color.b, color.a);
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if (d > 0) {
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x += xi;
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d += (2 * (dx - dy));
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} else {
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d += (2 * dx);
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}
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}
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return;
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}
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public:
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struct waymini* wm;
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uint32_t width;
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uint32_t height;
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uint32_t stride;
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uint8_t *pixels;
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Draw(uint32_t width, uint32_t height, waymini_key_cb on_key) {
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this->wm = waymini_create(width, height, on_key, NULL);
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if (!this->wm) exit(1);
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this->width = waymini_get_width(this->wm);
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this->height = waymini_get_height(this->wm);
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this->stride = waymini_get_stride(this->wm);
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printf("surface: %ux%u stride=%u\n", this->width, this->height, this->stride);
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this->pixels = (uint8_t *)waymini_get_pixels(this->wm);
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if (!this->pixels) {
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waymini_destroy(this->wm);
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exit(1);
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}
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}
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// Draw a rectangle (duh)
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void rectangle(Coord2 point0, Coord2 point1, Color color) {
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if (point0.x > this->width || point0.y > this->height || point1.x > this->width || point1.y > this->height) {return;};
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for (uint32_t y = point0.y; y < point1.y; y++) {
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for (uint32_t x = point0.x; x < point1.x; x++) {
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putPixel(x, y, color.r, color.g, color.b, color.a);
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}
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}
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return;
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}
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// Draws a rectangle with a 4-point color gradient
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void rectangleGradient(Coord2 point0, Coord2 point1, Color colorUL, Color colorUR, Color colorLL, Color colorLR) {
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// convert to int32_t and ensure x1>x0 && y1>y0
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int32_t x0, y0, x1, y1;
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if (point0.x > point1.x) {
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x0 = (int32_t)point1.x;
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x1 = (int32_t)point0.x;
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} else {
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x0 = (int32_t)point0.x;
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x1 = (int32_t)point1.x;
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}
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if (point0.y > point1.y) {
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y0 = (int32_t)point1.y;
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y1 = (int32_t)point0.y;
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} else {
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y0 = (int32_t)point0.y;
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y1 = (int32_t)point1.y;
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}
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// setup gradient coefficient arrays
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int32_t w = x1 - x0 + 1;
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int32_t h = y1 - y0 + 1;
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int16_t xGrad[w];
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int16_t yGrad[h];
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// calculate gradient coefficients
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this->bresenham(0, w - 1, 255, xGrad);
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this->bresenham(0, h - 1, 255, yGrad);
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// for each point calculate, alpha blend and print color
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Color Lmix = Color();
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Color Rmix = Color();
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Color Xmix = Color();
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for (int32_t y = y0; y <= y1; y++) {
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Lmix = this->lerpColor(colorUL, colorLL, (uint8_t)yGrad[y - y0]);
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Rmix = this->lerpColor(colorUR, colorLR, (uint8_t)yGrad[y - y0]);
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for (int32_t x = x0; x <= x1; x++) {
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Xmix = this->lerpColor(Lmix, Rmix, (uint8_t)xGrad[x - x0]);
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putPixel(x, y, Xmix.r, Xmix.g, Xmix.b, Xmix.a);
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}
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}
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return;
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}
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// Fill a simple gradient. Each row is stride bytes.
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void rainbow() {
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for (uint32_t y = 0; y < this->height; y++) {
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for (uint32_t x = 0; x < this->width; x++) {
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size_t i = (size_t)y * waymini_get_stride(this->wm) + (size_t)x * 4;
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this->pixels[i + 0] = (uint8_t)(y * 255 / this->height); // B
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this->pixels[i + 1] = 0x00; // G
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this->pixels[i + 2] = (uint8_t)(x * 255 / this->width); // R
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this->pixels[i + 3] = 0xFF; // A
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}
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}
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}
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// Draw a single point
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void point (Coord2 point, Color color) {
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if (point.x > this->width || point.y > this->height) {return;};
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putPixel(point.x, point.y, color.r, color.g, color.b, color.a);
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}
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// Uses Bresenham's line algorithm to draw line of any slope
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void line (Coord2 point0, Coord2 point1, Color color) {
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if (point0.x > this->width || point0.y > this->height || point1.x > this->width || point1.y > this->height) {return;};
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int32_t x0 = (int32_t)point0.x;
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int32_t y0 = (int32_t)point0.y;
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int32_t x1 = (int32_t)point1.x;
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int32_t y1 = (int32_t)point1.y;
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if (abs(y1 - y0) < abs(x1 - x0)) {
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if (x0 > x1) {
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this->lineLow(x1, y1, x0, y0, color);
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} else {
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this->lineLow(x0, y0, x1, y1, color);
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}
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} else {
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if (y0 > y1) {
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this->lineHigh(x1, y1, x0, y0, color);
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} else {
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this->lineHigh(x0, y0, x1, y1, color);
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}
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}
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}
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// Draw a horizontally bounded trapezoid
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// coords.y1 >= coords.y0
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void trapezoid (Trapezoid coords, Color color) {
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uint16_t height = 1 + coords.y1 - coords.y0;
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int16_t LeftBound[height];
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int16_t RightBound[height];
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this->bresenham(coords.xl0, coords.y1 - coords.y0, coords.xl1, LeftBound);
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this->bresenham(coords.xr0, coords.y1 - coords.y0, coords.xr1, RightBound);
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for (uint16_t i = 0; i <= height; i++) {
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for (uint16_t x = LeftBound[i]; x <= RightBound[i]; x++) {
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this->putPixel((uint32_t)x, (uint32_t)i + coords.y0, color.r, color.g, color.b, color.a);
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}
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}
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return;
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}
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};
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}
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int main(void) {
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uint32_t w = 800, h = 480;
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UwU::Color fuchsia = UwU::Color(0xb00b6940);
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UwU::Color red = UwU::Color(0xff0000ff);
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UwU::Color green = UwU::Color(0x00ff00ff);
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UwU::Color blue = UwU::Color(0x0000ffff);
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UwU::Color alpha = UwU::Color(0x00000000);
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printf("r: %u, g:%u, b:%u, a:%u\n", fuchsia.r, fuchsia.g, fuchsia.b, fuchsia.a);
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// struct waymini *wm = waymini_create(w, h, on_key, NULL);
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UwU::Draw draw = UwU::Draw(w, h, on_key);
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draw.rainbow();
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draw.rectangle(UwU::Coord2(69, 69), UwU::Coord2(420, 420), fuchsia);
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draw.rectangleGradient(UwU::Coord2(200, 200), UwU::Coord2(600, 400), red, blue, alpha, red);
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draw.trapezoid(UwU::Trapezoid(300, 400, 360, 360, 600, 401), green);
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draw.point(UwU::Coord2(387, 43), green);
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draw.line(UwU::Coord2(300, 100), UwU::Coord2(250, 469), green);
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draw.line(UwU::Coord2(250, 100), UwU::Coord2(300, 469), green);
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draw.line(UwU::Coord2(300, 100), UwU::Coord2(469, 250), green);
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draw.line(UwU::Coord2(469, 100), UwU::Coord2(300, 250), green);
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draw.line(UwU::Coord2(100, 300), UwU::Coord2(250, 469), green);
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draw.line(UwU::Coord2(250, 300), UwU::Coord2(100, 469), green);
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draw.line(UwU::Coord2(100, 300), UwU::Coord2(469, 250), green);
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draw.line(UwU::Coord2(469, 300), UwU::Coord2(100, 250), green);
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waymini_present(draw.wm);
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while (!waymini_should_close(draw.wm)) {
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if (waymini_dispatch(draw.wm) < 0) break;
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}
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waymini_destroy(draw.wm);
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return 0;
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}
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