playfield.hh

/*

MIT License

Copyright (c) 2022 PCSX-Redux authors

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
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furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.

*/

#pragma once

#include <stdint.h>

#include "constants.hh"
#include "pieces.hh"
#include "psyqo/fragments.hh"
#include "psyqo/gpu.hh"
#include "psyqo/primitives/rectangles.hh"
#include "rand.hh"

// The Playfield class will be responsible for holding the basic state
// of the playfield, and drawing it to the screen. It's technically
// variable sized, at compilation time, using the template arguments.
// The default Tetris configuration is 10 columns and 20 rows.
template <size_t COLUMNS, size_t ROWS>
struct Playfield {
    static constexpr size_t Columns = COLUMNS;
    static constexpr size_t Rows = ROWS;

  private:
    enum CellType : uint8_t { Empty, Cyan, Yellow, Purple, Blue, Orange, Red, Green };
    static constexpr unsigned BLOCK_SIZE = 10;
    static constexpr unsigned SCREEN_WIDTH = 320;
    static constexpr unsigned SCREEN_HEIGHT = 240;
    static constexpr unsigned LEFT = SCREEN_WIDTH / 2 - (BLOCK_SIZE * COLUMNS / 2);
    static constexpr unsigned TOP = SCREEN_HEIGHT / 2 - (BLOCK_SIZE * ROWS / 2);

    // First, we will have our game logic methods.
  public:
    // Empties the playfield. This needs to be called at initialization time only,
    // as it touches the fragments. This is the only method that is mutating the
    // fragments implicitly.
    void clear() {
        for (size_t x = 0; x < COLUMNS; x++) {
            for (size_t y = 0; y < ROWS; y++) {
                m_cells[x][y] = Empty;
            }
        }
        m_fieldFragment.count = 0;
        m_blockFragment.count = 0;
    }

    // Fills the playfield with random blocks.
    void fillRandom(Rand& rand) {
        for (size_t x = 0; x < COLUMNS; x++) {
            for (size_t y = 0; y < ROWS; y++) {
                m_cells[x][y] = CellType(rand.rand<7>() + 1);
            }
        }
    }

    // Returns true if the given block collisions with anything at the given position.
    bool collision(unsigned block, int x, int y, unsigned rotation) {
        for (size_t i = 0; i < 4; i++) {
            for (size_t j = 0; j < 4; j++) {
                if (PIECES[block - 1][rotation][j][i]) {
                    int xx = x + i;
                    int yy = y + j;
                    if ((xx < 0) || (yy < 0) || (xx >= COLUMNS) || (yy >= ROWS) || (m_cells[xx][yy] != Empty)) {
                        return true;
                    }
                }
            }
        }
        return false;
    }

    // Cements a block into the playfield.
    void place(unsigned block, int x, int y, unsigned rotation) {
        for (size_t i = 0; i < 4; i++) {
            for (size_t j = 0; j < 4; j++) {
                if (PIECES[block - 1][rotation][j][i]) {
                    m_cells[x + i][y + j] = CellType(block);
                }
            }
        }
    }

    // Computes the amount of lines that are complete, and remove them.
    // Returns the number of removed lines.
    int removeLines() {
        int lines = 0;
        for (size_t y = 0; y < ROWS; y++) {
            bool full = true;
            for (size_t x = 0; x < COLUMNS; x++) {
                if (m_cells[x][y] == Empty) {
                    full = false;
                    break;
                }
            }
            if (full) {
                for (size_t x = 0; x < COLUMNS; x++) {
                    m_cells[x][y] = Empty;
                }
                for (size_t yy = y; yy > 0; yy--) {
                    for (size_t x = 0; x < COLUMNS; x++) {
                        m_cells[x][yy] = m_cells[x][yy - 1];
                    }
                }
                y--;
                lines++;
            }
        }
        return lines;
    }

    // Then, the drawing-related methods.
  private:
    // The playfield fragment contains a fixed prologue of two rectangles
    // to draw the background and exterior.
    struct Prologue {
        psyqo::Prim::Rectangle outerField;
        psyqo::Prim::Rectangle innerField;
    };
    // This represents one of the blocks drawn in the playfield.
    struct Block {
        psyqo::Prim::Rectangle outer;
        psyqo::Prim::Rectangle8x8 inner;
    };

    // We are using a `FixedFragmentWithPrologue` to store the playfield Fragment.
    // We have a maximum of `ROWS * COLUMNS` blocks to display, so that's the
    // maximu amount of elements we need in our fragment.
    psyqo::Fragments::FixedFragmentWithPrologue<Prologue, Block, ROWS * COLUMNS> m_fieldFragment;
    // The current block fragment is a fixed fragment with a maximum of 4 blocks.
    // There is a subtle difference in the way we're drawing the current tetromino
    // blocks, compared to the blocks on the playfield. The current block fragment
    // won't have contours, to try and symbolize a sort of cement that's added when
    // a tetromino is fused in the playfield.
    psyqo::Fragments::FixedFragment<psyqo::Prim::Rectangle8x8, 4> m_blockFragment;

    // The pause screen will hide the current playfield and block, setting the
    // fragments counts to 0, so we need to keep track of the previous values
    // to simply re-assign them when we're being unpaused.
    unsigned m_oldFieldFragmentCount;
    unsigned m_oldBlockFragmentCount;

  public:
    // In our constructor, we're initializing the pieces of the fragments
    // that will never change throughout the lifetime of the game.
    Playfield() {
        m_fieldFragment.prologue.outerField.position.x = LEFT - 2;
        m_fieldFragment.prologue.outerField.position.y = TOP;
        m_fieldFragment.prologue.outerField.size.x = BLOCK_SIZE * COLUMNS + 4;
        m_fieldFragment.prologue.outerField.size.y = BLOCK_SIZE * ROWS + 2;
        m_fieldFragment.prologue.outerField.setColor(DARKERGREY);
        m_fieldFragment.prologue.innerField.position.x = LEFT;
        m_fieldFragment.prologue.innerField.position.y = TOP;
        m_fieldFragment.prologue.innerField.size.x = BLOCK_SIZE * COLUMNS;
        m_fieldFragment.prologue.innerField.size.y = BLOCK_SIZE * ROWS;
        m_fieldFragment.prologue.innerField.setColor(DARKGREY);
        for (auto& block : m_fieldFragment.primitives) {
            block.outer.size.w = block.outer.size.h = BLOCK_SIZE;
        }
        clear();
    }

    // This method is called when the game is paused. It simply empties
    // the fragments to hide the blocks.
    void emptyFragments() {
        m_oldFieldFragmentCount = m_fieldFragment.count;
        m_oldBlockFragmentCount = m_blockFragment.count;
        m_fieldFragment.count = 0;
        m_blockFragment.count = 0;
    }

    // This method is called when the game is unpaused. It simply re-assigns
    // the fragments to their previous values so everything is being
    // displayed again.
    void restoreFragments() {
        m_fieldFragment.count = m_oldFieldFragmentCount;
        m_blockFragment.count = m_oldBlockFragmentCount;
    }

    // This method needs to be called after the playfield has been changed in
    // any way. It will mutate the fragments to reflect the new playfield,
    // so it is not safe to call from a callback, but only from the `::frame()`
    // method of a scene.
    void updateFieldFragment() {
        unsigned counter = 0;
        // We simply walk over the whole playfield, and update the fragment
        // accordingly. The will count the number of actual blocks being
        // displayed in our fragment to assign it at the end of the loops.
        for (size_t x = 0; x < COLUMNS; ++x) {
            for (size_t y = 0; y < ROWS; ++y) {
                bool addme = true;
                auto& block = m_fieldFragment.primitives[counter];
                switch (m_cells[x][y]) {
                    case Empty:
                        addme = false;
                        break;
                    case Red:
                        block.outer.setColor(RED);
                        block.inner.setColor(HIRED);
                        break;
                    case Orange:
                        block.outer.setColor(ORANGE);
                        block.inner.setColor(HIORANGE);
                        break;
                    case Yellow:
                        block.outer.setColor(YELLOW);
                        block.inner.setColor(HIYELLOW);
                        break;
                    case Green:
                        block.outer.setColor(GREEN);
                        block.inner.setColor(HIGREEN);
                        break;
                    case Blue:
                        block.outer.setColor(BLUE);
                        block.inner.setColor(HIBLUE);
                        break;
                    case Cyan:
                        block.outer.setColor(CYAN);
                        block.inner.setColor(HICYAN);
                        break;
                    case Purple:
                        block.outer.setColor(PURPLE);
                        block.inner.setColor(HIPURPLE);
                        break;
                }
                if (addme) {
                    block.outer.position.x = LEFT + x * BLOCK_SIZE;
                    block.outer.position.y = TOP + y * BLOCK_SIZE;
                    block.inner.position.x = LEFT + x * BLOCK_SIZE + 1;
                    block.inner.position.y = TOP + y * BLOCK_SIZE + 1;
                    counter++;
                }
            }
        }
        m_fieldFragment.count = counter;
    }

    // This method needs to be called when the current tetromino has
    // changed in any way. This will mutate the fragments to reflect the
    // new current tetromino, so it is not safe to call from a callback,
    // but only from the `::frame()` method of a scene.
    void updateBlockFragment(unsigned block, unsigned x, unsigned y, unsigned rotation) {
        if (block == 0) {
            m_blockFragment.count = 0;
            return;
        }
        unsigned counter = 0;
        for (size_t i = 0; i < 4; i++) {
            for (size_t j = 0; j < 4; j++) {
                if (PIECES[block - 1][rotation][j][i]) {
                    auto& blockFragment = m_blockFragment.primitives[counter];
                    blockFragment.position.x = LEFT + x * BLOCK_SIZE + i * BLOCK_SIZE + 1;
                    blockFragment.position.y = TOP + y * BLOCK_SIZE + j * BLOCK_SIZE + 1;
                    blockFragment.setColor(PIECES_HICOLORS[block - 1]);
                    counter++;
                }
            }
        }
        m_blockFragment.count = counter;
    }

    // This method will render the playfield and the current tetromino.
    // The playfield fragment is too big to be chained, so we never
    // end up using DMA chaining during this example.
    void render(psyqo::GPU& gpu) {
        gpu.sendFragment(m_fieldFragment);
        gpu.sendFragment(m_blockFragment);
    }

  private:
    CellType m_cells[COLUMNS][ROWS];
};