diff options
Diffstat (limited to 'examples/snake')
| -rw-r--r-- | examples/snake/main.lua | 219 |
1 files changed, 219 insertions, 0 deletions
diff --git a/examples/snake/main.lua b/examples/snake/main.lua new file mode 100644 index 0000000..74b7191 --- /dev/null +++ b/examples/snake/main.lua @@ -0,0 +1,219 @@ +-- Defines +local RESOLUTION = { 128, 128 } +local TILE_SIZE = 8 +local LEVEL_SIZE = RESOLUTION[1] / TILE_SIZE +local STATE = { TITLE = 0, GAME = 1, OVER = 2 } -- Enum wannabe. + +-- Resources +local framebuffer = -1 +local monitor = 0 +local monitorPos = RL_GetMonitorPosition( monitor ) +local monitorSize = RL_GetMonitorSize( monitor ) +local winScale = 6 +local winSize = { RESOLUTION[1] * winScale, RESOLUTION[2] * winScale } +local gameState = STATE.GAME +local grassTexture = -1 +local snakeTexture = -1 +local appleTexture = -1 +local gameSpeed = 7.0 +local moveTimer = 1.0 +local snake = {} +local applePos = {} + +local function setSnake() + snake = { + heading = { 1, 0 }, + control = { 1, 0 }, + headPos = { LEVEL_SIZE / 2, LEVEL_SIZE / 2 }, + segments = {}, + grow = 2, + } +end + +local function vector2IsEqual( v1, v2 ) + return v1[1] == v2[1] and v1[2] == v2[2] +end + +local function addSegment() + -- If first segment, grow from head and otherwise from tail. New segments are inserted firts. + if #snake.segments == 0 then + table.insert( snake.segments, 1, { pos = snake.headPos, heading = snake.heading } ) + else + table.insert( snake.segments, 1, { pos = snake.segments[ #snake.segments ].pos, + heading = snake.segments[ #snake.segments ].heading } ) + end +end + +local function setApplePos() + applePos = { math.random( 0, LEVEL_SIZE - 1 ), math.random( 0, LEVEL_SIZE - 1 ) } + local search = true + + while search do + search = false + applePos = { math.random( 0, LEVEL_SIZE - 1 ), math.random( 0, LEVEL_SIZE - 1 ) } + + for _, seg in ipairs( snake.segments ) do + search = vector2IsEqual( applePos, seg.pos ) + + if search then + break + end + end + end +end + +-- Init. + +function init() + RL_SetWindowState( FLAG_WINDOW_RESIZABLE ) + RL_SetWindowSize( winSize ) + RL_SetWindowPosition( { monitorPos[1] + monitorSize[1] / 2 - winSize[1] / 2, monitorPos[2] + monitorSize[2] / 2 - winSize[2] / 2 } ) + RL_SetWindowTitle( "Snake" ) + RL_SetWindowIcon( RL_LoadImage( RL_GetBasePath().."../resources/images/apple.png" ) ) + + framebuffer = RL_LoadRenderTexture( RESOLUTION ) + grassTexture = RL_LoadTexture( RL_GetBasePath().."../resources/images/grass.png" ) + snakeTexture = RL_LoadTexture( RL_GetBasePath().."../resources/images/snake.png" ) + appleTexture = RL_LoadTexture( RL_GetBasePath().."../resources/images/apple.png" ) + + setSnake() + setApplePos() +end + +-- Process. + +local function moveSnake() + -- Check if snake has eaten and should grow. + if 0 < snake.grow then + addSegment() + snake.grow = snake.grow - 1 + end + -- Move body. + for i, seg in ipairs( snake.segments ) do + if i < #snake.segments then + seg.pos = snake.segments[ i+1 ].pos + seg.heading = snake.segments[ i+1 ].heading + else + seg.pos = snake.headPos + seg.heading = snake.heading + end + end + -- Move head. + snake.heading = { snake.control[1], snake.control[2] } + snake.headPos = { snake.headPos[1] + snake.heading[1], snake.headPos[2] + snake.heading[2] } + + -- Check appple eating. + if vector2IsEqual( snake.headPos, applePos ) then + snake.grow = snake.grow + 1 + setApplePos() + end + -- Check if hit to body. + for _, seg in ipairs( snake.segments ) do + if vector2IsEqual( snake.headPos, seg.pos ) then + gameState = STATE.OVER + end + end + -- Check if outside or level. + if snake.headPos[1] < 0 or LEVEL_SIZE <= snake.headPos[1] or snake.headPos[2] < 0 or LEVEL_SIZE <= snake.headPos[2] then + gameState = STATE.OVER + end + + moveTimer = moveTimer + 1.0 +end + +function process( delta ) + if gameState == STATE.GAME then -- Run game. + -- Controls. + if RL_IsKeyPressed( KEY_RIGHT ) and 0 <= snake.heading[1] then + snake.control = { 1, 0 } + elseif RL_IsKeyPressed( KEY_LEFT ) and snake.heading[1] <= 0 then + snake.control = { -1, 0 } + elseif RL_IsKeyPressed( KEY_DOWN ) and 0 <= snake.heading[2] then + snake.control = { 0, 1 } + elseif RL_IsKeyPressed( KEY_UP ) and snake.heading[2] <= 0 then + snake.control = { 0, -1 } + end + + moveTimer = moveTimer - gameSpeed * delta + + if moveTimer <= 0.0 then + moveSnake() + end + elseif gameState == STATE.OVER and RL_IsKeyPressed( KEY_ENTER ) then -- Reset game. + setSnake() + setApplePos() + gameState = STATE.GAME + end +end + +-- Drawing. + +local function drawGrass() + for y = 0, LEVEL_SIZE - 1 do + for x = 0, LEVEL_SIZE - 1 do + RL_DrawTexture( grassTexture, { x * TILE_SIZE, y * TILE_SIZE }, WHITE ) + end + end +end + +--[[ Check if next segment is on left side. There are more mathematically elegant solution to this, but there is +only four possibilities so we can just check them all. ]]-- +local function onLeft( this, next ) + return ( vector2IsEqual( this, { 0, -1 } ) and vector2IsEqual( next, { -1, 0 } ) ) + or ( vector2IsEqual( this, { -1, 0 } ) and vector2IsEqual( next, { 0, 1 } ) ) + or ( vector2IsEqual( this, { 0, 1 } ) and vector2IsEqual( next, { 1, 0 } ) ) + or ( vector2IsEqual( this, { 1, 0 } ) and vector2IsEqual( next, { 0, -1 } ) ) +end + +local function drawSnake() + for i, seg in ipairs( snake.segments ) do + local angle = math.deg( RL_Vector2Angle( { 0, 0 }, seg.heading ) ) + local source = { 16, 0, 8, 8 } + + if i == 1 then -- Tail segment. Yes tail is actually the 'first' segment. + source[1] = 8 + + if 1 < #snake.segments then + angle = math.deg( RL_Vector2Angle( { 0, 0 }, snake.segments[ 2 ].heading ) ) + end + elseif i < #snake.segments and not vector2IsEqual( seg.heading, snake.segments[ i+1 ].heading ) then -- Turned middle segments. + source[1] = 0 + -- Mirror turned segment to other way. + if onLeft( seg.heading, snake.segments[ i+1 ].heading ) then + source[4] = -8 + end + elseif i == #snake.segments and not vector2IsEqual( seg.heading, snake.heading ) then -- Turned segment before head. + source[1] = 0 + + if onLeft( seg.heading, snake.heading ) then + source[4] = -8 + end + end + -- Notice that we set the origin to center { 4, 4 } that acts as pivot point. We also have to adjust our dest position by 4. + RL_DrawTexturePro( snakeTexture, source, { seg.pos[1] * TILE_SIZE + 4, seg.pos[2] * TILE_SIZE + 4, 8, 8 }, { 4, 4 }, angle, WHITE ) + end + -- Let's draw the head last to keep it on top. + local angle = math.deg( RL_Vector2Angle( { 0, 0 }, snake.heading ) ) + RL_DrawTexturePro( snakeTexture, { 24, 0, 8, 8 }, { snake.headPos[1] * TILE_SIZE + 4, snake.headPos[2] * TILE_SIZE + 4, 8, 8 }, { 4, 4 }, angle, WHITE ) +end + +local function drawApple() + RL_DrawTexture( appleTexture, { applePos[1] * TILE_SIZE, applePos[2] * TILE_SIZE }, WHITE ) +end + +function draw() + -- Clear the window to black. + RL_ClearBackground( BLACK ) + -- Draw to framebuffer. + RL_BeginTextureMode( framebuffer ) + RL_ClearBackground( BLACK ) + drawGrass() + drawSnake() + drawApple() + RL_EndTextureMode() + + -- Draw framebuffer to window. + RL_SetTextureSource( TEXTURE_SOURCE_RENDER_TEXTURE ) + RL_DrawTexturePro( framebuffer, { 0, 0, RESOLUTION[1], -RESOLUTION[2] }, { 0, 0, winSize[1], winSize[2] }, { 0, 0 }, 0.0, WHITE ) + RL_SetTextureSource( TEXTURE_SOURCE_TEXTURE ) +end |