reasampler/tests/test_editor_geometry.cpp

// Standalone tests for reasampler::vst::editor_geometry — no VST3, no REAPER, no test
// framework. Same fast assert loop as the sibling pure tests (mode_switch et al.):
// assert the IPlugView LICE editor's layout math + hit-testing directly.
//
// Covers: contains() half-open convention + degenerate rects; layoutEditor regions on a
// normal view (title band + button + canvas), a tiny view (button clamped to canvas,
// never overhanging), and a zero view (all rects empty, no inversion); hitTest hitting
// the button, missing on the title/canvas, missing outside the surface, and boundary
// pixels; layout<->hit-test agreement (a click on the drawn button rect hits it).

#include "../src/vst/editor_geometry.h"

#include <cstdio>

using namespace reasampler::vst;

static int g_fail = 0;
#define CHECK(cond) do { if(!(cond)) { \
    std::printf("FAIL line %d: %s\n", __LINE__, #cond); ++g_fail; } } while(0)

// --- contains() ---------------------------------------------------------------

static void testContainsHalfOpen() {
    Rect r{10, 20, 50, 40};  // [10,50) x [20,40)
    CHECK(contains(r, 10, 20));     // top-left inclusive
    CHECK(contains(r, 49, 39));     // bottom-right exclusive edge, inside
    CHECK(!contains(r, 50, 30));    // right edge excluded
    CHECK(!contains(r, 30, 40));    // bottom edge excluded
    CHECK(!contains(r, 9, 30));     // left of rect
    CHECK(!contains(r, 30, 19));    // above rect
}

static void testContainsDegenerate() {
    CHECK(!contains(Rect{10, 10, 10, 20}, 10, 15));  // zero width
    CHECK(!contains(Rect{10, 10, 20, 10}, 15, 10));  // zero height
    CHECK(!contains(Rect{20, 10, 10, 20}, 15, 15));  // inverted (right < left)
}

// --- layoutEditor: normal view ------------------------------------------------

static void testLayoutNormalView() {
    // A comfortable 400x260 view: title band spans the top full width; canvas is the
    // rest; button sits inside the canvas, inset by the margin.
    const EditorLayout L = layoutEditor(400, 260);

    CHECK(L.titleBar.left == 0 && L.titleBar.top == 0);
    CHECK(L.titleBar.right == 400);
    CHECK(L.titleBar.height() > 0 && L.titleBar.height() <= 260);

    // Canvas begins right below the title bar and reaches the bottom-right.
    CHECK(L.canvas.top == L.titleBar.bottom);
    CHECK(L.canvas.right == 400 && L.canvas.bottom == 260);

    // Button is inside the canvas (does not overhang any edge).
    CHECK(L.button.left >= L.canvas.left);
    CHECK(L.button.top >= L.canvas.top);
    CHECK(L.button.right <= L.canvas.right);
    CHECK(L.button.bottom <= L.canvas.bottom);
    CHECK(L.button.width() > 0 && L.button.height() > 0);
}

// --- layoutEditor: tiny view (clamping) ---------------------------------------

static void testLayoutTinyViewClampsButton() {
    // A view narrower/shorter than the button's natural size: the button must clamp to
    // the canvas and never produce an inverted or overhanging rect.
    const EditorLayout L = layoutEditor(40, 40);
    CHECK(L.button.right <= L.canvas.right);
    CHECK(L.button.bottom <= L.canvas.bottom);
    CHECK(L.button.right >= L.button.left);   // never inverted
    CHECK(L.button.bottom >= L.button.top);
    // Title bar clamps to the client height when the view is shorter than its height.
    CHECK(L.titleBar.bottom <= 40);
}

// --- layoutEditor: zero view (all empty, no inversion) ------------------------

static void testLayoutZeroView() {
    const EditorLayout L = layoutEditor(0, 0);
    CHECK(L.titleBar.width() <= 0 || L.titleBar.height() <= 0);
    CHECK(L.canvas.width() <= 0 || L.canvas.height() <= 0);
    // No rect is inverted.
    CHECK(L.button.right >= L.button.left);
    CHECK(L.button.bottom >= L.button.top);
    CHECK(L.canvas.right >= L.canvas.left);
    CHECK(L.canvas.bottom >= L.canvas.top);
    // A click anywhere on an empty layout hits nothing.
    CHECK(hitTest(L, 0, 0) == HitTarget::kNone);
    CHECK(hitTest(L, 5, 5) == HitTarget::kNone);
}

// --- hitTest ------------------------------------------------------------------

static void testHitTestButton() {
    const EditorLayout L = layoutEditor(400, 260);
    // Center of the button hits it.
    const int cx = (L.button.left + L.button.right) / 2;
    const int cy = (L.button.top + L.button.bottom) / 2;
    CHECK(hitTest(L, cx, cy) == HitTarget::kButton);
}

static void testHitTestMissesNonButton() {
    const EditorLayout L = layoutEditor(400, 260);
    // Title bar is inert in the spike.
    CHECK(hitTest(L, 200, L.titleBar.top + 1) == HitTarget::kNone);
    // Empty canvas away from the button.
    CHECK(hitTest(L, 380, 240) == HitTarget::kNone);
    // Outside the surface entirely.
    CHECK(hitTest(L, -5, -5) == HitTarget::kNone);
    CHECK(hitTest(L, 500, 500) == HitTarget::kNone);
}

static void testHitTestButtonBoundary() {
    const EditorLayout L = layoutEditor(400, 260);
    // Top-left corner of the button is inclusive; the right/bottom edges are excluded.
    CHECK(hitTest(L, L.button.left, L.button.top) == HitTarget::kButton);
    CHECK(hitTest(L, L.button.right, L.button.top) == HitTarget::kNone);
    CHECK(hitTest(L, L.button.left, L.button.bottom) == HitTarget::kNone);
}

// --- layout<->hit-test agreement ----------------------------------------------

// Every pixel inside the drawn button rect must hit the button; this is the
// load-bearing consistency invariant between what the shell draws and what it routes.
static void testHitTestMatchesDrawnButton() {
    const EditorLayout L = layoutEditor(320, 200);
    for (int y = L.button.top; y < L.button.bottom; ++y) {
        for (int x = L.button.left; x < L.button.right; ++x) {
            CHECK(hitTest(L, x, y) == HitTarget::kButton);
        }
    }
}

int main() {
    testContainsHalfOpen();
    testContainsDegenerate();
    testLayoutNormalView();
    testLayoutTinyViewClampsButton();
    testLayoutZeroView();
    testHitTestButton();
    testHitTestMissesNonButton();
    testHitTestButtonBoundary();
    testHitTestMatchesDrawnButton();

    if (g_fail == 0) std::printf("editor_geometry: all tests passed\n");
    return g_fail != 0;
}