From 4efb60bb5be6545f024a50bb2ccdbcc7876a08c4 Mon Sep 17 00:00:00 2001
From: Gregor Klevze <gregor@klevze.si>
Date: Sun, 21 Dec 2025 15:59:46 +0100
Subject: [PATCH] added ghost block

---
 src/graphics/renderers/GameRenderer.cpp | 50 +++++++++++++++++++++++--
 1 file changed, 46 insertions(+), 4 deletions(-)

diff --git a/src/graphics/renderers/GameRenderer.cpp b/src/graphics/renderers/GameRenderer.cpp
index 0cc1dab..57d9dbe 100644
--- a/src/graphics/renderers/GameRenderer.cpp
+++ b/src/graphics/renderers/GameRenderer.cpp
@@ -2106,7 +2106,7 @@ void GameRenderer::renderCoopPlayingState(
         if (t >= 1.0f) sf.active = false;
     };
 
-    auto drawPiece = [&](const CoopGame::Piece& p, CoopGame::PlayerSide side, const std::pair<float,float>& offsets) {
+    auto drawPiece = [&](const CoopGame::Piece& p, const std::pair<float, float>& offsets, bool isGhost) {
         for (int cy = 0; cy < 4; ++cy) {
             for (int cx = 0; cx < 4; ++cx) {
                 if (!CoopGame::cellFilled(p, cx, cy)) continue;
@@ -2115,7 +2115,17 @@ void GameRenderer::renderCoopPlayingState(
                 if (pyIdx < 0) continue; // don't draw parts above the visible grid
                 float px = gridX + (float)pxIdx * finalBlockSize + offsets.first;
                 float py = gridY + (float)pyIdx * finalBlockSize + offsets.second;
-                drawBlockTexturePublic(renderer, blocksTex, px, py, finalBlockSize, p.type);
+                if (isGhost) {
+                    SDL_SetRenderDrawBlendMode(renderer, SDL_BLENDMODE_BLEND);
+                    SDL_SetRenderDrawColor(renderer, 180, 180, 180, 20);
+                    SDL_FRect rect = {px + 2.0f, py + 2.0f, finalBlockSize - 4.0f, finalBlockSize - 4.0f};
+                    SDL_RenderFillRect(renderer, &rect);
+                    SDL_SetRenderDrawColor(renderer, 180, 180, 180, 30);
+                    SDL_FRect border = {px + 1.0f, py + 1.0f, finalBlockSize - 2.0f, finalBlockSize - 2.0f};
+                    SDL_RenderRect(renderer, &border);
+                } else {
+                    drawBlockTexturePublic(renderer, blocksTex, px, py, finalBlockSize, p.type);
+                }
             }
         }
     };
@@ -2125,14 +2135,46 @@ void GameRenderer::renderCoopPlayingState(
     drawSpawnFadeIfActive(s_leftSpawnFade);
     drawSpawnFadeIfActive(s_rightSpawnFade);
 
+    // Draw classic-style ghost pieces (landing position), grid-aligned.
+    // This intentionally does NOT use smoothing offsets.
+    auto computeGhostPiece = [&](CoopGame::PlayerSide side) {
+        CoopGame::Piece ghostPiece = game->current(side);
+        const auto& boardRef = game->boardRef();
+        while (true) {
+            CoopGame::Piece testPiece = ghostPiece;
+            testPiece.y++;
+            bool collision = false;
+            for (int cy = 0; cy < 4; ++cy) {
+                for (int cx = 0; cx < 4; ++cx) {
+                    if (!CoopGame::cellFilled(testPiece, cx, cy)) continue;
+                    int gx = testPiece.x + cx;
+                    int gy = testPiece.y + cy;
+                    if (gy >= CoopGame::ROWS || gx < 0 || gx >= CoopGame::COLS ||
+                        (gy >= 0 && boardRef[gy * CoopGame::COLS + gx].occupied)) {
+                        collision = true;
+                        break;
+                    }
+                }
+                if (collision) break;
+            }
+            if (collision) break;
+            ghostPiece = testPiece;
+        }
+        return ghostPiece;
+    };
+
+    const std::pair<float, float> ghostOffsets{0.0f, 0.0f};
+    drawPiece(computeGhostPiece(CoopGame::PlayerSide::Left), ghostOffsets, true);
+    drawPiece(computeGhostPiece(CoopGame::PlayerSide::Right), ghostOffsets, true);
+
     // If a spawn fade is active for a side and matches the current piece
     // sequence, only draw the fade visual and skip the regular piece draw
     // to avoid a double-draw that appears as a jump when falling starts.
     if (!(s_leftSpawnFade.active && s_leftSpawnFade.seq == game->currentPieceSequence(CoopGame::PlayerSide::Left))) {
-        drawPiece(game->current(CoopGame::PlayerSide::Left), CoopGame::PlayerSide::Left, leftOffsets);
+        drawPiece(game->current(CoopGame::PlayerSide::Left), leftOffsets, false);
     }
     if (!(s_rightSpawnFade.active && s_rightSpawnFade.seq == game->currentPieceSequence(CoopGame::PlayerSide::Right))) {
-        drawPiece(game->current(CoopGame::PlayerSide::Right), CoopGame::PlayerSide::Right, rightOffsets);
+        drawPiece(game->current(CoopGame::PlayerSide::Right), rightOffsets, false);
     }
 
     // Next panels (two)