From 4ffa1895390066f2bbd347c0689a1b667a21fd24 Mon Sep 17 00:00:00 2001 From: 3gg <3gg@shellblade.net> Date: Fri, 27 Jun 2025 10:17:41 -0700 Subject: Initial commit --- src/backend.c | 199 ++++++++++++ src/isogfx.c | 952 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 1151 insertions(+) create mode 100644 src/backend.c create mode 100644 src/isogfx.c (limited to 'src') diff --git a/src/backend.c b/src/backend.c new file mode 100644 index 0000000..db91647 --- /dev/null +++ b/src/backend.c @@ -0,0 +1,199 @@ +#include +#include + +#include +#include +#include +#include +#include +#include + +#include +#include + +typedef struct IsoBackend { + Gfx* gfx; + Scene* scene; + /// The screen or "iso screen" refers to the colour buffer of the iso graphics + /// library. This texture is used to draw the iso screen onto the graphics + /// window. + Texture* screen_texture; + /// Window size. + int window_width; + int window_height; + /// The viewport refers to the area inside the window to which screen_texture + /// is drawn. It is a scaled version of the iso screen, scaled while + /// respecting the iso screen's aspect ratio to prevent distortion. + int viewport_x, viewport_y, viewport_width, viewport_height; + double stretch; // Stretch factor from iso screen dimensions to viewport + // dimensions. +} IsoBackend; + +IsoBackend* IsoBackendInit(const IsoGfx* iso) { + assert(iso); + + IsoBackend* backend = calloc(1, sizeof(IsoBackend)); + if (!backend) { + return 0; + } + + if (!(backend->gfx = gfx_init())) { + goto cleanup; + } + GfxCore* gfxcore = gfx_get_core(backend->gfx); + + int screen_width, screen_height; + isogfx_get_screen_size(iso, &screen_width, &screen_height); + + if (!(backend->screen_texture = gfx_make_texture( + gfxcore, &(TextureDesc){ + .width = screen_width, + .height = screen_height, + .dimension = Texture2D, + .format = TextureSRGBA8, + .filtering = NearestFiltering, + .wrap = ClampToEdge, + .mipmaps = false}))) { + goto cleanup; + } + + ShaderProgram* shader = gfx_make_view_texture_shader(gfxcore); + if (!shader) { + goto cleanup; + } + + Geometry* geometry = gfx_make_quad_11(gfxcore); + if (!geometry) { + goto cleanup; + } + + MaterialDesc material_desc = (MaterialDesc){.num_uniforms = 1}; + material_desc.uniforms[0] = (ShaderUniform){ + .type = UniformTexture, + .value.texture = backend->screen_texture, + .name = sstring_make("Texture")}; + Material* material = gfx_make_material(&material_desc); + if (!material) { + return false; + } + + const MeshDesc mesh_desc = + (MeshDesc){.geometry = geometry, .material = material, .shader = shader}; + Mesh* mesh = gfx_make_mesh(&mesh_desc); + if (!mesh) { + goto cleanup; + } + + SceneObject* object = + gfx_make_object(&(ObjectDesc){.num_meshes = 1, .meshes = {mesh}}); + if (!object) { + goto cleanup; + } + + backend->scene = gfx_make_scene(); + SceneNode* node = gfx_make_object_node(object); + SceneNode* root = gfx_get_scene_root(backend->scene); + gfx_set_node_parent(node, root); + + return backend; + +cleanup: + if (backend->gfx) { + gfx_destroy(&backend->gfx); + } + free(backend); + return 0; +} + +void IsoBackendShutdown(IsoBackend** ppApp) { + assert(ppApp); + + IsoBackend* app = *ppApp; + if (!app) { + return; + } + + gfx_destroy(&app->gfx); +} + +void IsoBackendResizeWindow( + IsoBackend* app, const IsoGfx* iso, int width, int height) { + assert(app); + assert(iso); + + app->window_width = width; + app->window_height = height; + + // Virtual screen dimensions. + int screen_width, screen_height; + isogfx_get_screen_size(iso, &screen_width, &screen_height); + + // Stretch the virtual screen onto the viewport while respecting the screen's + // aspect ratio to prevent distortion. + if (width > height) { // Wide screen. + app->stretch = (double)height / (double)screen_height; + app->viewport_width = (int)((double)screen_width * app->stretch); + app->viewport_height = height; + app->viewport_x = (width - app->viewport_width) / 2; + app->viewport_y = 0; + } else { // Tall screen. + app->stretch = (double)width / (double)screen_width; + app->viewport_width = width; + app->viewport_height = (int)((float)screen_height * app->stretch); + app->viewport_x = 0; + app->viewport_y = (height - app->viewport_height) / 2; + } +} + +void IsoBackendRender(const IsoBackend* app, const IsoGfx* iso) { + assert(app); + assert(iso); + + const Pixel* screen = isogfx_get_screen_buffer(iso); + assert(screen); + gfx_update_texture(app->screen_texture, &(TextureDataDesc){.pixels = screen}); + + GfxCore* gfxcore = gfx_get_core(app->gfx); + Renderer* renderer = gfx_get_renderer(app->gfx); + + // Clear the whole window. + gfx_set_viewport(gfxcore, 0, 0, app->window_width, app->window_height); + gfx_clear(gfxcore, vec4_make(0, 0, 0, 0)); + + // Draw to the subregion where the virtual screen can stretch without + // distortion. + gfx_set_viewport( + gfxcore, app->viewport_x, app->viewport_y, app->viewport_width, + app->viewport_height); + + // Render the iso screen. + gfx_start_frame(gfxcore); + gfx_render_scene( + renderer, &(RenderSceneParams){ + .mode = RenderDefault, .scene = app->scene, .camera = 0}); + gfx_end_frame(gfxcore); +} + +bool IsoBackendGetMousePosition( + const IsoBackend* app, double window_x, double window_y, double* x, + double* y) { + assert(app); + + // Translate from window coordinates to the subregion where the stretched + // iso screen is rendered. + const double screen_x = window_x - app->viewport_x; + const double screen_y = window_y - app->viewport_y; + + // Position may be out of bounds. + if ((0 <= screen_x) && (screen_x < app->viewport_width) && (0 <= screen_y) && + (screen_y < app->viewport_height)) { + // Scale back from the stretched subregion to the iso screen dimensions. + *x = screen_x / app->stretch; + *y = screen_y / app->stretch; + return true; + } else { + *x = -1; + *y = -1; + return false; + } +} diff --git a/src/isogfx.c b/src/isogfx.c new file mode 100644 index 0000000..52c4ae2 --- /dev/null +++ b/src/isogfx.c @@ -0,0 +1,952 @@ +#include + +#include +#include +#include +#include + +#include + +#include +#include +#include +#include +#include +#include + +/// Maximum number of tiles unless the user specifies a value. +#define DEFAULT_MAX_NUM_TILES 1024 + +/// Maximum number of sprites unless the user specifies a value. +#define DEFAULT_MAX_NUM_SPRITES 128 + +/// Size of sprite sheet pool in bytes unless the user specifies a value. +#define DEFAULT_SPRITE_SHEET_POOL_SIZE_BYTES (8 * 1024 * 1024) + +/// Default animation speed. +#define ANIMATION_FPS 10 + +/// Time between animation updates. +#define ANIMATION_UPDATE_DELTA (1.0 / ANIMATION_FPS) + +typedef struct ivec2 { + int x, y; +} ivec2; + +typedef struct vec2 { + double x, y; +} vec2; + +// ----------------------------------------------------------------------------- +// Tile set (TS) and tile map (TM) file formats. +// ----------------------------------------------------------------------------- + +/// Maximum length of path strings in .TS and .TM files. +#define MAX_PATH_LENGTH 128 + +typedef struct Ts_Tile { + uint16_t width; /// Tile width in pixels. + uint16_t height; /// Tile height in pixels. + Pixel pixels[1]; /// Count: width * height. +} Ts_Tile; + +typedef struct Ts_TileSet { + uint16_t num_tiles; + uint16_t max_tile_width; /// Maximum tile width in pixels. + uint16_t max_tile_height; /// Maximum tile height in pixels. + Ts_Tile tiles[1]; /// Count: num_tiles. +} Ts_TileSet; + +typedef struct Tm_Layer { + union { + char tileset_path[MAX_PATH_LENGTH]; // Relative to the Tm_Map file. + }; + Tile tiles[1]; /// Count: world_width * world_height. +} Tm_Layer; + +typedef struct Tm_Map { + uint16_t world_width; /// World width in number of tiles. + uint16_t world_height; /// World height in number of tiles. + uint16_t base_tile_width; + uint16_t base_tile_height; + uint16_t num_layers; + Tm_Layer layers[1]; // Count: num_layers. +} Tm_Map; + +static inline const Tm_Layer* tm_map_get_next_layer( + const Tm_Map* map, const Tm_Layer* layer) { + assert(map); + assert(layer); + return (const Tm_Layer*)((const uint8_t*)layer + sizeof(Tm_Layer) + + ((map->world_width * map->world_height - 1) * + sizeof(Tile))); +} + +static inline const Ts_Tile* ts_tileset_get_next_tile( + const Ts_TileSet* tileset, const Ts_Tile* tile) { + assert(tileset); + assert(tile); + return (const Ts_Tile*)((const uint8_t*)tile + sizeof(Ts_Tile) + + ((tile->width * tile->height - 1) * sizeof(Pixel))); +} + +// ----------------------------------------------------------------------------- +// Sprite sheet file format. +// ----------------------------------------------------------------------------- + +/// A row of sprites in a sprite sheet. +/// +/// Each row in a sprite sheet can have a different number of columns. +/// +/// The pixels of the row follow a "sprite-major" order. It contains the +/// 'sprite_width * sprite_height' pixels for the first column/sprite, then the +/// second column/sprite, etc. +/// +/// Pixels are 8-bit indices into the sprite sheet's colour palette. +typedef struct Ss_Row { + uint16_t num_cols; /// Number of columns in this row. + uint8_t pixels[1]; /// Count: num_cols * sprite_width * sprite_height. +} Ss_Row; + +typedef struct Ss_Palette { + uint16_t num_colours; + Pixel colours[1]; /// Count: num_colors. +} Ss_Palette; + +/// Sprite sheet top-level data definition. +/// +/// Sprite width and height are assumed constant throughout the sprite sheet. +typedef struct Ss_SpriteSheet { + uint16_t sprite_width; /// Sprite width in pixels. + uint16_t sprite_height; /// Sprite height in pixels. + uint16_t num_rows; + Ss_Palette palette; /// Variable size. + Ss_Row rows[1]; /// Count: num_rows. Variable offset. +} Ss_SpriteSheet; + +static inline const Ss_Row* get_sprite_sheet_row( + const Ss_SpriteSheet* sheet, int row) { + assert(sheet); + assert(row >= 0); + assert(row < sheet->num_rows); + // Skip over the palette. + const Ss_Row* rows = + (const Ss_Row*)(&sheet->palette.colours[0] + sheet->palette.num_colours); + return &rows[row]; +} + +static inline const uint8_t* get_sprite_sheet_sprite( + const Ss_SpriteSheet* sheet, const Ss_Row* row, int col) { + assert(sheet); + assert(row); + assert(col >= 0); + assert(col < row->num_cols); + const int sprite_offset = col * sheet->sprite_width * sheet->sprite_height; + const uint8_t* sprite = &row->pixels[sprite_offset]; + return sprite; +} + +// ----------------------------------------------------------------------------- +// Renderer state. +// ----------------------------------------------------------------------------- + +typedef struct TileData { + uint16_t width; + uint16_t height; + uint16_t pixels_handle; // Handle to the tile's pixels in the pixel pool. +} TileData; + +// File format is already convenient for working in memory. +typedef Ss_Row SpriteSheetRow; +typedef Ss_SpriteSheet SpriteSheetData; + +typedef struct SpriteData { + SpriteSheet sheet; // Handle to the sprite's sheet. + ivec2 position; + int animation; // Current animation. + int frame; // Current frame of animation. +} SpriteData; + +DEF_MEMPOOL_DYN(TilePool, TileData) +DEF_MEM_DYN(PixelPool, Pixel) + +DEF_MEMPOOL_DYN(SpritePool, SpriteData) +DEF_MEM_DYN(SpriteSheetPool, SpriteSheetData) + +typedef struct IsoGfx { + int screen_width; + int screen_height; + int tile_width; + int tile_height; + int world_width; + int world_height; + int max_num_sprites; + int sprite_sheet_pool_size_bytes; + double last_animation_time; + Tile* world; + Pixel* screen; + TilePool tiles; + PixelPool pixels; + SpritePool sprites; + SpriteSheetPool sheets; +} IsoGfx; + +// ----------------------------------------------------------------------------- +// Math and world / tile / screen access. +// ----------------------------------------------------------------------------- + +static inline ivec2 ivec2_add(ivec2 a, ivec2 b) { + return (ivec2){.x = a.x + b.x, .y = a.y + b.y}; +} + +static inline ivec2 ivec2_scale(ivec2 a, int s) { + return (ivec2){.x = a.x * s, .y = a.y * s}; +} + +static inline ivec2 iso2cart(ivec2 iso, int s, int t, int w) { + return (ivec2){ + .x = (iso.x - iso.y) * (s / 2) + (w / 2), .y = (iso.x + iso.y) * (t / 2)}; +} + +// Method 1. +// static inline vec2 cart2iso(vec2 cart, int s, int t, int w) { +// const double x = cart.x - (double)(w / 2); +// const double xiso = (x * t + cart.y * s) / (double)(s * t); +// return (vec2){ +// .x = (int)(xiso), .y = (int)((2.0 / (double)t) * cart.y - xiso)}; +//} + +// Method 2. +static inline vec2 cart2iso(vec2 cart, int s, int t, int w) { + const double one_over_s = 1. / (double)s; + const double one_over_t = 1. / (double)t; + const double x = cart.x - (double)(w / 2); + return (vec2){ + .x = (one_over_s * x + one_over_t * cart.y), + .y = (-one_over_s * x + one_over_t * cart.y)}; +} + +static const Pixel* tile_xy_const_ref( + const IsoGfx* iso, const TileData* tile, int x, int y) { + assert(iso); + assert(tile); + assert(x >= 0); + assert(y >= 0); + assert(x < tile->width); + assert(y < tile->height); + return &mem_get_chunk(&iso->pixels, tile->pixels_handle)[y * tile->width + x]; +} + +// static Pixel tile_xy(const IsoGfx* iso, const TileData* tile, int x, int y) { +// return *tile_xy_const_ref(iso, tile, x, y); +// } + +static Pixel* tile_xy_mut(const IsoGfx* iso, TileData* tile, int x, int y) { + return (Pixel*)tile_xy_const_ref(iso, tile, x, y); +} + +static inline const Tile* world_xy_const_ref(const IsoGfx* iso, int x, int y) { + assert(iso); + assert(x >= 0); + assert(y >= 0); + assert(x < iso->world_width); + assert(y < iso->world_height); + return &iso->world[y * iso->world_width + x]; +} + +static inline Tile world_xy(const IsoGfx* iso, int x, int y) { + return *world_xy_const_ref(iso, x, y); +} + +static inline Tile* world_xy_mut(IsoGfx* iso, int x, int y) { + return (Tile*)world_xy_const_ref(iso, x, y); +} + +static inline const Pixel* screen_xy_const_ref( + const IsoGfx* iso, int x, int y) { + assert(iso); + assert(x >= 0); + assert(y >= 0); + assert(x < iso->screen_width); + assert(y < iso->screen_height); + return &iso->screen[y * iso->screen_width + x]; +} + +static inline Pixel screen_xy(IsoGfx* iso, int x, int y) { + return *screen_xy_const_ref(iso, x, y); +} + +static inline Pixel* screen_xy_mut(IsoGfx* iso, int x, int y) { + return (Pixel*)screen_xy_const_ref(iso, x, y); +} + +static int calc_num_tile_blocks( + int base_tile_width, int base_tile_height, int tile_width, + int tile_height) { + const int base_tile_size = base_tile_width * base_tile_height; + const int tile_size = tile_width * tile_height; + const int num_blocks = tile_size / base_tile_size; + return num_blocks; +} + +// ----------------------------------------------------------------------------- +// Renderer, world and tile management. +// ----------------------------------------------------------------------------- + +IsoGfx* isogfx_new(const IsoGfxDesc* desc) { + assert(desc->screen_width > 0); + assert(desc->screen_height > 0); + // Part of our implementation assumes even widths and heights for precision. + assert((desc->screen_width & 1) == 0); + assert((desc->screen_height & 1) == 0); + + IsoGfx* iso = calloc(1, sizeof(IsoGfx)); + if (!iso) { + return 0; + } + + iso->screen_width = desc->screen_width; + iso->screen_height = desc->screen_height; + + iso->last_animation_time = 0.0; + + iso->max_num_sprites = desc->max_num_sprites == 0 ? DEFAULT_MAX_NUM_SPRITES + : desc->max_num_sprites; + iso->sprite_sheet_pool_size_bytes = desc->sprite_sheet_pool_size_bytes == 0 + ? DEFAULT_SPRITE_SHEET_POOL_SIZE_BYTES + : desc->sprite_sheet_pool_size_bytes; + + const int screen_size = desc->screen_width * desc->screen_height; + if (!(iso->screen = calloc(screen_size, sizeof(Pixel)))) { + goto cleanup; + } + + return iso; + +cleanup: + isogfx_del(&iso); + return 0; +} + +/// Destroy the world, its tile set, and the underlying pools. +static void destroy_world(IsoGfx* iso) { + assert(iso); + if (iso->world) { + free(iso->world); + iso->world = 0; + } + mempool_del(&iso->tiles); + mem_del(&iso->pixels); +} + +/// Destroy all loaded sprites and the underlying pools. +static void destroy_sprites(IsoGfx* iso) { + assert(iso); + mempool_del(&iso->sprites); + mem_del(&iso->sheets); +} + +void isogfx_del(IsoGfx** pIso) { + assert(pIso); + IsoGfx* iso = *pIso; + if (iso) { + destroy_world(iso); + destroy_sprites(iso); + if (iso->screen) { + free(iso->screen); + iso->screen = 0; + } + free(iso); + *pIso = 0; + } +} + +bool isogfx_make_world(IsoGfx* iso, const WorldDesc* desc) { + assert(iso); + assert(desc); + assert(desc->tile_width > 0); + assert(desc->tile_height > 0); + // Part of our implementation assumes even widths and heights for greater + // precision. + assert((desc->tile_width & 1) == 0); + assert((desc->tile_height & 1) == 0); + + // Handle recreation by destroying the previous world. + destroy_world(iso); + + iso->tile_width = desc->tile_width; + iso->tile_height = desc->tile_height; + iso->world_width = desc->world_width; + iso->world_height = desc->world_height; + + const int world_size = desc->world_width * desc->world_height; + const int tile_size = desc->tile_width * desc->tile_height; + const int tile_size_bytes = tile_size * (int)sizeof(Pixel); + const int tile_pool_size = + desc->max_num_tiles > 0 ? desc->max_num_tiles : DEFAULT_MAX_NUM_TILES; + + if (!(iso->world = calloc(world_size, sizeof(Tile)))) { + goto cleanup; + } + if (!mempool_make_dyn(&iso->tiles, world_size, sizeof(TileData))) { + goto cleanup; + } + if (!mem_make_dyn(&iso->pixels, tile_pool_size, tile_size_bytes)) { + goto cleanup; + } + + return true; + +cleanup: + destroy_world(iso); + return false; +} + +bool isogfx_load_world(IsoGfx* iso, const char* filepath) { + assert(iso); + assert(filepath); + + bool success = false; + + // Handle recreation by destroying the previous world. + destroy_world(iso); + + // Load the map. + printf("Load tile map: %s\n", filepath); + Tm_Map* map = read_file(filepath); + if (!map) { + goto cleanup; + } + + // Allocate memory for the map and tile sets. + const int world_size = map->world_width * map->world_height; + const int base_tile_size = map->base_tile_width * map->base_tile_height; + const int base_tile_size_bytes = base_tile_size * (int)sizeof(Pixel); + // TODO: Need to get the total number of tiles from the map. + const int tile_pool_size = DEFAULT_MAX_NUM_TILES; + + if (!(iso->world = calloc(world_size, sizeof(Tile)))) { + goto cleanup; + } + if (!mempool_make_dyn(&iso->tiles, tile_pool_size, sizeof(TileData))) { + goto cleanup; + } + if (!mem_make_dyn(&iso->pixels, tile_pool_size, base_tile_size_bytes)) { + goto cleanup; + } + + // Load the tile sets. + const Tm_Layer* layer = &map->layers[0]; + // TODO: Handle num_layers layers. + for (int i = 0; i < 1; ++i) { + const char* ts_path = layer->tileset_path; + + // Tile set path is relative to the tile map file. Make it relative to the + // current working directory before loading. + char ts_path_cwd[PATH_MAX] = {0}; + if (!path_make_relative(filepath, ts_path, ts_path_cwd, PATH_MAX)) { + goto cleanup; + } + + Ts_TileSet* tileset = read_file(ts_path_cwd); + if (!tileset) { + goto cleanup; + }; + + // Load tile data. + const Ts_Tile* tile = &tileset->tiles[0]; + for (uint16_t j = 0; j < tileset->num_tiles; ++j) { + // Tile dimensions should be a multiple of the base tile size. + assert((tile->width % map->base_tile_width) == 0); + assert((tile->height % map->base_tile_height) == 0); + + // Allocate N base tile size blocks for the tile. + const uint16_t tile_size = tile->width * tile->height; + const int num_blocks = tile_size / base_tile_size; + Pixel* pixels = mem_alloc(&iso->pixels, num_blocks); + assert(pixels); + memcpy(pixels, tile->pixels, tile_size * sizeof(Pixel)); + + // Allocate the tile data. + TileData* tile_data = mempool_alloc(&iso->tiles); + assert(tile_data); + tile_data->width = tile->width; + tile_data->height = tile->height; + tile_data->pixels_handle = + (uint16_t)mem_get_chunk_handle(&iso->pixels, pixels); + + tile = ts_tileset_get_next_tile(tileset, tile); + } + + printf("Loaded tile set (%u tiles): %s\n", tileset->num_tiles, ts_path_cwd); + + free(tileset); + layer = tm_map_get_next_layer(map, layer); + } + + // Load the map into the world. + layer = &map->layers[0]; + // TODO: Handle num_layers layers. + for (int i = 0; i < 1; ++i) { + memcpy(iso->world, layer->tiles, world_size * sizeof(Tile)); + + // TODO: We need to handle 'firsgid' in TMX files. + for (int j = 0; j < world_size; ++j) { + iso->world[j] -= 1; + } + + layer = tm_map_get_next_layer(map, layer); + } + + iso->world_width = map->world_width; + iso->world_height = map->world_height; + iso->tile_width = map->base_tile_width; + iso->tile_height = map->base_tile_height; + + success = true; + +cleanup: + if (map) { + free(map); + } + if (!success) { + destroy_world(iso); + } + return success; +} + +int isogfx_world_width(const IsoGfx* iso) { + assert(iso); + return iso->world_width; +} + +int isogfx_world_height(const IsoGfx* iso) { + assert(iso); + return iso->world_height; +} + +/// Create a tile mask procedurally. +static void make_tile_from_colour( + const IsoGfx* iso, Pixel colour, TileData* tile) { + assert(iso); + assert(tile); + + const int width = tile->width; + const int height = tile->height; + const int r = width / height; + + for (int y = 0; y < height / 2; ++y) { + const int mask_start = width / 2 - r * y - 1; + const int mask_end = width / 2 + r * y + 1; + for (int x = 0; x < width; ++x) { + const bool mask = (mask_start <= x) && (x <= mask_end); + const Pixel val = mask ? colour : (Pixel){.r = 0, .g = 0, .b = 0, .a = 0}; + + // Top half. + *tile_xy_mut(iso, tile, x, y) = val; + + // Bottom half reflects the top half. + const int y_reflected = height - y - 1; + *tile_xy_mut(iso, tile, x, y_reflected) = val; + } + } +} + +Tile isogfx_make_tile(IsoGfx* iso, const TileDesc* desc) { + assert(iso); + assert(desc); + // Client must create world before creating tiles. + assert(iso->tile_width > 0); + assert(iso->tile_height > 0); + + TileData* tile = mempool_alloc(&iso->tiles); + assert(tile); // TODO: Make this a hard assert. + + const int num_blocks = calc_num_tile_blocks( + iso->tile_width, iso->tile_height, desc->width, desc->height); + + Pixel* pixels = mem_alloc(&iso->pixels, num_blocks); + assert(pixels); // TODO: Make this a hard assert. + + tile->width = desc->width; + tile->height = desc->height; + tile->pixels_handle = mem_get_chunk_handle(&iso->pixels, pixels); + + switch (desc->type) { + case TileFromColour: + make_tile_from_colour(iso, desc->colour, tile); + break; + case TileFromFile: + assert(false); // TODO + break; + case TileFromMemory: + assert(false); // TODO + break; + } + + return (Tile)mempool_get_block_index(&iso->tiles, tile); +} + +void isogfx_set_tile(IsoGfx* iso, int x, int y, Tile tile) { + assert(iso); + *world_xy_mut(iso, x, y) = tile; +} + +void isogfx_set_tiles(IsoGfx* iso, int x0, int y0, int x1, int y1, Tile tile) { + assert(iso); + for (int y = y0; y < y1; ++y) { + for (int x = x0; x < x1; ++x) { + isogfx_set_tile(iso, x, y, tile); + } + } +} + +bool isogfx_load_sprite_sheet( + IsoGfx* iso, const char* filepath, SpriteSheet* p_sheet) { + assert(iso); + assert(filepath); + assert(p_sheet); + + bool success = false; + + // Lazy initialization of sprite pools. + if (mempool_capacity(&iso->sprites) == 0) { + if (!mempool_make_dyn( + &iso->sprites, iso->max_num_sprites, sizeof(SpriteData))) { + return false; + } + } + if (mem_capacity(&iso->sheets) == 0) { + // Using a block size of 1 byte for sprite sheet data. + if (!mem_make_dyn(&iso->sheets, iso->sprite_sheet_pool_size_bytes, 1)) { + return false; + } + } + + // Load sprite sheet file. + printf("Load sprite sheet: %s\n", filepath); + FILE* file = fopen(filepath, "rb"); + if (file == NULL) { + goto cleanup; + } + const size_t sheet_size = get_file_size(file); + SpriteSheetData* ss_sheet = mem_alloc(&iso->sheets, sheet_size); + if (!ss_sheet) { + goto cleanup; + } + if (fread(ss_sheet, sheet_size, 1, file) != 1) { + goto cleanup; + } + + *p_sheet = mem_get_chunk_handle(&iso->sheets, ss_sheet); + success = true; + +cleanup: + // Pools remain initialized since client may attempt to load other sprites. + if (file != NULL) { + fclose(file); + } + if (!success) { + if (ss_sheet) { + mem_free(&iso->sheets, &ss_sheet); + } + } + return success; +} + +Sprite isogfx_make_sprite(IsoGfx* iso, SpriteSheet sheet) { + assert(iso); + + SpriteData* sprite = mempool_alloc(&iso->sprites); + assert(sprite); + + sprite->sheet = sheet; + + return mempool_get_block_index(&iso->sprites, sprite); +} + +#define with_sprite(SPRITE, BODY) \ + { \ + SpriteData* data = mempool_get_block(&iso->sprites, sprite); \ + assert(data); \ + BODY; \ + } + +void isogfx_set_sprite_position(IsoGfx* iso, Sprite sprite, int x, int y) { + assert(iso); + with_sprite(sprite, { + data->position.x = x; + data->position.y = y; + }); +} + +void isogfx_set_sprite_animation(IsoGfx* iso, Sprite sprite, int animation) { + assert(iso); + with_sprite(sprite, { data->animation = animation; }); +} + +void isogfx_update(IsoGfx* iso, double t) { + assert(iso); + + // If this is the first time update() is called after initialization, just + // record the starting animation time. + if (iso->last_animation_time == 0.0) { + iso->last_animation_time = t; + return; + } + + if ((t - iso->last_animation_time) >= ANIMATION_UPDATE_DELTA) { + // TODO: Consider linking animated sprites in a list so that we only walk + // over those here and not also the static sprites. + mempool_foreach(&iso->sprites, sprite, { + const SpriteSheetData* sheet = mem_get_chunk(&iso->sheets, sprite->sheet); + assert(sheet); // TODO: Make this a hard assert inside the mem/pool. + const SpriteSheetRow* row = + get_sprite_sheet_row(sheet, sprite->animation); + sprite->frame = (sprite->frame + 1) % row->num_cols; + }); + + iso->last_animation_time = t; + } +} + +// ----------------------------------------------------------------------------- +// Rendering and picking. +// ----------------------------------------------------------------------------- + +typedef struct CoordSystem { + ivec2 o; /// Origin. + ivec2 x; + ivec2 y; +} CoordSystem; + +/// Create the basis for the isometric coordinate system with origin and vectors +/// expressed in the Cartesian system. +static CoordSystem make_iso_coord_system(const IsoGfx* iso) { + assert(iso); + const ivec2 o = {iso->screen_width / 2, 0}; + const ivec2 x = {.x = iso->tile_width / 2, .y = iso->tile_height / 2}; + const ivec2 y = {.x = -iso->tile_width / 2, .y = iso->tile_height / 2}; + return (CoordSystem){o, x, y}; +} + +/// Get the screen position of the top diamond-corner of the tile at world +/// (x,y). +static ivec2 GetTileScreenOrigin( + const CoordSystem iso_space, int world_x, int world_y) { + const ivec2 vx_offset = ivec2_scale(iso_space.x, world_x); + const ivec2 vy_offset = ivec2_scale(iso_space.y, world_y); + const ivec2 screen_origin = + ivec2_add(iso_space.o, ivec2_add(vx_offset, vy_offset)); + + return screen_origin; +} + +static Pixel alpha_blend(Pixel src, Pixel dst) { + if ((src.a == 255) || (dst.a == 0)) { + return src; + } + const uint16_t one_minus_alpha = 255 - src.a; +#define blend(s, d) \ + (Channel)( \ + (double)((uint16_t)s * (uint16_t)src.a + \ + (uint16_t)d * one_minus_alpha) / \ + 255.0) + return (Pixel){ + .r = blend(src.r, dst.r), + .g = blend(src.g, dst.g), + .b = blend(src.b, dst.b), + .a = src.a}; +} + +/// Draw a rectangle (tile or sprite). +/// +/// The rectangle's top-left corner is mapped to the screen space position given +/// by 'top_left'. +/// +/// The rectangle's pixels are assumed to be arranged in a linear, row-major +/// fashion. +/// +/// If indices are given, then the image is assumed to be colour-paletted, where +/// 'pixels' is the palette and 'indices' the pixel indices. Otherwise, the +/// image is assumed to be in plain RGBA format. +static void draw_rect( + IsoGfx* iso, ivec2 top_left, int rect_width, int rect_height, + const Pixel* pixels, const uint8_t* indices) { + assert(iso); + +#define rect_pixel(X, Y) \ + (indices ? pixels[indices[Y * rect_width + X]] : pixels[Y * rect_width + X]) + + // Rect origin can be outside screen bounds, so we must offset accordingly to + // draw only the visible portion. +#define max(a, b) (a > b ? a : b) + const int px_offset = max(0, -top_left.x); + const int py_offset = max(0, -top_left.y); + + // Rect can exceed screen bounds, so clip along Y and X as we draw. + for (int py = py_offset; + (py < rect_height) && (top_left.y + py < iso->screen_height); ++py) { + const int sy = top_left.y + py; + for (int px = px_offset; + (px < rect_width) && (top_left.x + px < iso->screen_width); ++px) { + const Pixel colour = rect_pixel(px, py); + if (colour.a > 0) { + const int sx = top_left.x + px; + const Pixel dst = screen_xy(iso, sx, sy); + const Pixel final = alpha_blend(colour, dst); + *screen_xy_mut(iso, sx, sy) = final; + } + } + } +} + +/// Draw a tile. +/// +/// 'screen_origin' is the screen coordinates of the top diamond-corner of the +/// tile (the base tile for super tiles). +/// World (0, 0) -> (screen_width / 2, 0). +static void draw_tile(IsoGfx* iso, ivec2 screen_origin, Tile tile) { + assert(iso); + + const TileData* tile_data = mempool_get_block(&iso->tiles, tile); + assert(tile_data); + const Pixel* pixels = tile_xy_const_ref(iso, tile_data, 0, 0); + + // Move from the top diamond-corner to the top-left corner of the tile image. + // For regular tiles, tile height == base tile height, so the y offset is 0. + // For super tiles, move as high up as the height of the tile. + const ivec2 offset = { + -(iso->tile_width / 2), tile_data->height - iso->tile_height}; + const ivec2 top_left = ivec2_add(screen_origin, offset); + + draw_rect(iso, top_left, tile_data->width, tile_data->height, pixels, 0); +} + +static void draw_world(IsoGfx* iso) { + assert(iso); + + const int W = iso->screen_width; + const int H = iso->screen_height; + + memset(iso->screen, 0, W * H * sizeof(Pixel)); + + const CoordSystem iso_space = make_iso_coord_system(iso); + + // TODO: Culling. + // Ex: map the screen corners to tile space to cull. + // Ex: walk in screen space and fetch the tile. + // The tile-centric approach might be more cache-friendly since the + // screen-centric approach would juggle multiple tiles throughout the scan. + for (int wy = 0; wy < iso->world_height; ++wy) { + for (int wx = 0; wx < iso->world_width; ++wx) { + const Tile tile = world_xy(iso, wx, wy); + const ivec2 screen_origin = GetTileScreenOrigin(iso_space, wx, wy); + draw_tile(iso, screen_origin, tile); + } + } +} + +static void draw_sprite( + IsoGfx* iso, ivec2 origin, const SpriteData* sprite, + const SpriteSheetData* sheet) { + assert(iso); + assert(sprite); + assert(sheet); + assert(sprite->animation >= 0); + assert(sprite->animation < sheet->num_rows); + assert(sprite->frame >= 0); + + const SpriteSheetRow* row = get_sprite_sheet_row(sheet, sprite->animation); + const uint8_t* frame = get_sprite_sheet_sprite(sheet, row, sprite->frame); + draw_rect( + iso, origin, sheet->sprite_width, sheet->sprite_height, + sheet->palette.colours, frame); +} + +static void draw_sprites(IsoGfx* iso) { + assert(iso); + + const CoordSystem iso_space = make_iso_coord_system(iso); + + mempool_foreach(&iso->sprites, sprite, { + const SpriteSheetData* sheet = mem_get_chunk(&iso->sheets, sprite->sheet); + assert(sheet); + + const ivec2 screen_origin = + GetTileScreenOrigin(iso_space, sprite->position.x, sprite->position.y); + draw_sprite(iso, screen_origin, sprite, sheet); + }); +} + +void isogfx_render(IsoGfx* iso) { + assert(iso); + draw_world(iso); + draw_sprites(iso); +} + +void isogfx_draw_tile(IsoGfx* iso, int x, int y, Tile tile) { + assert(iso); + assert(x >= 0); + assert(y >= 0); + assert(x < iso->world_width); + assert(y < iso->world_height); + + const CoordSystem iso_space = make_iso_coord_system(iso); + const ivec2 screen_origin = GetTileScreenOrigin(iso_space, x, y); + draw_tile(iso, screen_origin, tile); +} + +bool isogfx_resize(IsoGfx* iso, int screen_width, int screen_height) { + assert(iso); + assert(iso->screen); + + const int current_size = iso->screen_width * iso->screen_height; + const int new_size = screen_width * screen_height; + + if (new_size > current_size) { + Pixel* new_screen = calloc(new_size, sizeof(Pixel)); + if (new_screen) { + free(iso->screen); + iso->screen = new_screen; + } else { + return false; + } + } + iso->screen_width = screen_width; + iso->screen_height = screen_height; + return true; +} + +void isogfx_get_screen_size(const IsoGfx* iso, int* width, int* height) { + assert(iso); + assert(width); + assert(height); + *width = iso->screen_width; + *height = iso->screen_height; +} + +const Pixel* isogfx_get_screen_buffer(const IsoGfx* iso) { + assert(iso); + return iso->screen; +} + +void isogfx_pick_tile( + const IsoGfx* iso, double xcart, double ycart, int* xiso, int* yiso) { + assert(iso); + assert(xiso); + assert(yiso); + + const vec2 xy_iso = cart2iso( + (vec2){.x = xcart, .y = ycart}, iso->tile_width, iso->tile_height, + iso->screen_width); + + if ((0 <= xy_iso.x) && (xy_iso.x < iso->world_width) && (0 <= xy_iso.y) && + (xy_iso.y < iso->world_height)) { + *xiso = (int)xy_iso.x; + *yiso = (int)xy_iso.y; + } else { + *xiso = -1; + *yiso = -1; + } +} -- cgit v1.2.3