keira: cube demo, RAM icon fix (#70)

firmware/keira/src/apps/demos/cube.cpp

@@ -0,0 +1,119 @@
+#include "cube.h"
+
+CubeApp::CubeApp() : App("Cube") {
+}
+
+typedef struct vec2 {
+    float x, y;
+} vec2;
+
+typedef struct vec3 {
+    float x, y, z;
+} vec3;
+
+vec2 add(vec2 a, vec2 b) {
+    return {a.x + b.x, a.y + b.y};
+}
+
+vec2 neg(vec2 a) {
+    return {-a.x, -a.y};
+}
+
+vec3 add(vec3 a, vec3 b) {
+    return {a.x + b.x, a.y + b.y, a.z + b.z};
+}
+
+vec3 mul(vec3 a, float f) {
+    return {a.x * f, a.y * f, a.z * f};
+}
+
+float sqr(float a) {
+    return a * a;
+}
+
+vec3 rotate(vec3 v, vec3 axis, float angle) {
+    float s = sin(angle);
+    float c = cos(angle);
+    return {
+        v.x * (c + sqr(axis.x) * (1 - c)) + v.y * (axis.x * axis.y * (1 - c) - axis.z * s) +
+            v.z * (axis.x * axis.z * (1 - c) + axis.y * s),
+        v.x * (axis.y * axis.x * (1 - c) + axis.z * s) + v.y * (c + sqr(axis.y) * (1 - c)) +
+            v.z * (axis.y * axis.z * (1 - c) - axis.x * s),
+        v.x * (axis.z * axis.x * (1 - c) - axis.y * s) + v.y * (axis.z * axis.y * (1 - c) + axis.x * s) +
+            v.z * (c + sqr(axis.z) * (1 - c)),
+    };
+}
+
+typedef struct line {
+    vec3 a, b;
+} line;
+
+vec2 project(vec3 v, lilka::Canvas* canvas) {
+    return {
+        v.x / (v.z * 0.25f) * canvas->height() / 4.0f + canvas->width() / 2.0f,
+        v.y / (v.z * 0.25f) * canvas->height() / 4.0f + canvas->height() / 2.0f,
+    };
+}
+
+void drawLines(
+    lilka::Canvas* canvas, const line* lines, int count, int thickness, float angle, float angle2, int32_t color
+) {
+    for (int i = 0; i < count; i++) {
+        vec3 axis = rotate({0, 1, 0}, {0, 0, 1}, angle);
+        vec3 a = rotate(lines[i].a, axis, angle2);
+        vec3 b = rotate(lines[i].b, axis, angle2);
+        a.z += 4;
+        b.z += 4;
+
+        vec2 aa = project(a, canvas);
+        vec2 bb = project(b, canvas);
+
+        if (color < 0) {
+            color = canvas->color565(random(128, 255), random(128, 255), random(128, 255));
+        }
+        for (int y = 0; y < thickness; y++) {
+            for (int x = 0; x < thickness; x++) {
+                canvas->drawLine(aa.x + x, aa.y + y, bb.x + x, bb.y + y, color);
+            }
+        }
+    }
+}
+
+void CubeApp::run() {
+    line cube[] = {
+        {{-1, -1, -1}, {-1, 1, -1}},
+        {{-1, 1, -1}, {1, 1, -1}},
+        {{1, 1, -1}, {1, -1, -1}},
+        {{1, -1, -1}, {-1, -1, -1}},
+        {{-1, -1, 1}, {-1, 1, 1}},
+        {{-1, 1, 1}, {1, 1, 1}},
+        {{1, 1, 1}, {1, -1, 1}},
+        {{1, -1, 1}, {-1, -1, 1}},
+        {{-1, -1, -1}, {-1, -1, 1}},
+        {{-1, 1, -1}, {-1, 1, 1}},
+        {{1, 1, -1}, {1, 1, 1}},
+        {{1, -1, -1}, {1, -1, 1}},
+    };
+
+    constexpr uint8_t size = sizeof(cube) / sizeof(cube[0]);
+
+    line cube2[size];
+    for (int i = 0; i < size; i++) {
+        cube2[i].a = mul(cube[i].a, 0.5);
+        cube2[i].b = mul(cube[i].b, 0.5);
+    }
+
+    while (1) {
+        lilka::State state = lilka::controller.getState();
+        if (state.a.justPressed) {
+            return;
+        }
+
+        float time = millis() / 1000.0f;
+
+        canvas->fillScreen(0);
+        drawLines(canvas, cube2, size, 1, (-time - 1) * 3.1415, (-time - 1) * 3.1415 * 1.3, 0xFFFF);
+        drawLines(canvas, cube, size, 3, time * 3.1415, time * 3.1415 * 1.3, -1);
+        queueDraw();
+    }
+}

firmware/keira/src/apps/demos/cube.h

@@ -0,0 +1,11 @@
+#pragma once
+
+#include "app.h"
+
+class CubeApp : public App {
+public:
+    CubeApp();
+
+private:
+    void run() override;
+};