add sprite flipping, cleanup some lua things

.luarc.json

@@ -0,0 +1,19 @@
+{
+  "runtime": {
+    "version": "LuaJIT"
+  },
+  "diagnostics": {
+    "globals": [
+      "pxl8",
+      "pxl8_gfx",
+      "pxl8_input",
+      "pxl8_rng",
+      "pxl8_sfx",
+      "pxl8_sys"
+    ],
+    "disable": [
+      "lowercase-global",
+      "unbalanced-assignments"
+    ]
+  }
+}

demo/main.fnl

@@ -95,7 +95,7 @@
     :logo (do
             (pxl8.clear 0)
             (when logo-sprite
-              (pxl8.sprite logo-sprite logo-x logo-y 128 64)))
+              (pxl8.sprite logo-sprite logo-x logo-y 128 64 (< logo-dx 0) (< logo-dy 0))))
 
     :plasma (pxl8.vfx_plasma time 0.10 0.04 1)
 

src/lua/pxl8.lua

@@ -1,5 +1,3 @@
-local ffi = require("ffi")
-
 local core = require("pxl8.core")
 local gfx2d = require("pxl8.gfx2d")
 local input = require("pxl8.input")
@@ -13,11 +11,10 @@ local world = require("pxl8.world")
 local transition = require("pxl8.transition")
 local anim = require("pxl8.anim")
 local sfx = require("pxl8.sfx")
-
-core.init(_pxl8_gfx, _pxl8_input, _pxl8_rng, _pxl8_sfx_mixer, _pxl8_sys)
-
 local pxl8 = {}
 
+core.init(pxl8_gfx, pxl8_input, pxl8_rng, pxl8_sfx, pxl8_sys)
+
 pxl8.get_fps = core.get_fps
 pxl8.get_height = core.get_height
 pxl8.get_title = core.get_title

src/lua/pxl8/core.lua

@@ -3,11 +3,11 @@ local C = ffi.C
 
 local core = {}
 
-function core.init(gfx, input, rng, sfx_mixer, sys)
+function core.init(gfx, input, rng, sfx, sys)
     core.gfx = gfx
     core.input = input
     core.rng = rng
-    core.sfx_mixer = sfx_mixer
+    core.sfx = sfx
     core.sys = sys
 end
 

src/lua/pxl8/sfx.lua

@@ -105,15 +105,15 @@ function sfx.delay_set_time(node, time_l, time_r)
 end
 
 function sfx.get_master_volume()
-    return C.pxl8_sfx_mixer_get_master_volume(core.sfx_mixer)
+    return C.pxl8_sfx_mixer_get_master_volume(core.sfx)
 end
 
 function sfx.mixer_attach(ctx)
-    C.pxl8_sfx_mixer_attach(core.sfx_mixer, ctx)
+    C.pxl8_sfx_mixer_attach(core.sfx, ctx)
 end
 
 function sfx.mixer_detach(ctx)
-    C.pxl8_sfx_mixer_detach(core.sfx_mixer, ctx)
+    C.pxl8_sfx_mixer_detach(core.sfx, ctx)
 end
 
 function sfx.node_destroy(node)
@@ -154,7 +154,7 @@ function sfx.reverb_set_room(node, room)
 end
 
 function sfx.set_master_volume(volume)
-    C.pxl8_sfx_mixer_set_master_volume(core.sfx_mixer, volume)
+    C.pxl8_sfx_mixer_set_master_volume(core.sfx, volume)
 end
 
 function sfx.stop_all(ctx)

src/pxl8_gfx.c

@@ -590,7 +590,7 @@ void pxl8_text(pxl8_gfx* gfx, const char* text, i32 x, i32 y, u32 color) {
 }
 
 
-void pxl8_sprite(pxl8_gfx* gfx, u32 sprite_id, i32 x, i32 y, i32 w, i32 h) {
+void pxl8_sprite(pxl8_gfx* gfx, u32 sprite_id, i32 x, i32 y, i32 w, i32 h, bool flip_x, bool flip_y) {
     if (!gfx || !gfx->atlas || !gfx->framebuffer) return;
 
     const pxl8_atlas_entry* entry = pxl8_atlas_get_entry(gfx->atlas, sprite_id);
@@ -611,11 +611,12 @@ void pxl8_sprite(pxl8_gfx* gfx, u32 sprite_id, i32 x, i32 y, i32 w, i32 h) {
 
     bool is_1to1_scale = (w == entry->w && h == entry->h);
     bool is_unclipped = (clip_left == 0 && clip_top == 0 && clip_right == 0 && clip_bottom == 0);
+    bool is_flipped = flip_x || flip_y;
 
     u32 atlas_width = pxl8_atlas_get_width(gfx->atlas);
     const u8* atlas_pixels = pxl8_atlas_get_pixels(gfx->atlas);
 
-    if (is_1to1_scale && is_unclipped) {
+    if (is_1to1_scale && is_unclipped && !is_flipped) {
         if (gfx->pixel_mode == PXL8_PIXEL_HICOLOR) {
             const u16* sprite_data = (const u16*)atlas_pixels + entry->y * atlas_width + entry->x;
             pxl8_blit_hicolor(
@@ -638,8 +639,12 @@ void pxl8_sprite(pxl8_gfx* gfx, u32 sprite_id, i32 x, i32 y, i32 w, i32 h) {
     } else {
         for (i32 py = 0; py < draw_height; py++) {
             for (i32 px = 0; px < draw_width; px++) {
-                i32 src_x = entry->x + ((px + clip_left) * entry->w) / w;
+                i32 local_x = (px + clip_left) * entry->w / w;
-                i32 src_y = entry->y + ((py + clip_top) * entry->h) / h;
+                i32 local_y = (py + clip_top) * entry->h / h;
+
+                i32 src_x = flip_x ? entry->x + entry->w - 1 - local_x : entry->x + local_x;
+                i32 src_y = flip_y ? entry->y + entry->h - 1 - local_y : entry->y + local_y;
+
                 i32 src_idx = src_y * atlas_width + src_x;
                 i32 dest_idx = (dest_y + py) * gfx->framebuffer_width + (dest_x + px);
 

src/pxl8_gfx.h

@@ -65,7 +65,7 @@ void pxl8_line(pxl8_gfx* gfx, i32 x0, i32 y0, i32 x1, i32 y1, u32 color);
 void pxl8_pixel(pxl8_gfx* gfx, i32 x, i32 y, u32 color);
 void pxl8_rect(pxl8_gfx* gfx, i32 x, i32 y, i32 w, i32 h, u32 color);
 void pxl8_rect_fill(pxl8_gfx* gfx, i32 x, i32 y, i32 w, i32 h, u32 color);
-void pxl8_sprite(pxl8_gfx* gfx, u32 sprite_id, i32 x, i32 y, i32 w, i32 h);
+void pxl8_sprite(pxl8_gfx* gfx, u32 sprite_id, i32 x, i32 y, i32 w, i32 h, bool flip_x, bool flip_y);
 void pxl8_text(pxl8_gfx* gfx, const char* text, i32 x, i32 y, u32 color);
 
 void pxl8_3d_clear_zbuffer(pxl8_gfx* gfx);

src/pxl8_script.c

@@ -677,7 +677,7 @@ void pxl8_script_set_gfx(pxl8_script* script, pxl8_gfx* gfx) {
     script->gfx = gfx;
     if (script->L && gfx) {
         lua_pushlightuserdata(script->L, gfx);
-        lua_setglobal(script->L, "_pxl8_gfx");
+        lua_setglobal(script->L, "pxl8_gfx");
     }
 }
 
@@ -686,7 +686,7 @@ void pxl8_script_set_input(pxl8_script* script, pxl8_input_state* input) {
     script->input = input;
     if (script->L && input) {
         lua_pushlightuserdata(script->L, input);
-        lua_setglobal(script->L, "_pxl8_input");
+        lua_setglobal(script->L, "pxl8_input");
     }
 }
 
@@ -694,7 +694,7 @@ void pxl8_script_set_rng(pxl8_script* script, void* rng) {
     if (!script) return;
     if (script->L && rng) {
         lua_pushlightuserdata(script->L, rng);
-        lua_setglobal(script->L, "_pxl8_rng");
+        lua_setglobal(script->L, "pxl8_rng");
     }
 }
 
@@ -703,7 +703,7 @@ void pxl8_script_set_sfx(pxl8_script* script, pxl8_sfx_mixer* mixer) {
     script->mixer = mixer;
     if (script->L && mixer) {
         lua_pushlightuserdata(script->L, mixer);
-        lua_setglobal(script->L, "_pxl8_sfx_mixer");
+        lua_setglobal(script->L, "pxl8_sfx");
     }
 }
 
@@ -711,7 +711,7 @@ void pxl8_script_set_sys(pxl8_script* script, void* sys) {
     if (!script) return;
     if (script->L && sys) {
         lua_pushlightuserdata(script->L, sys);
-        lua_setglobal(script->L, "_pxl8_sys");
+        lua_setglobal(script->L, "pxl8_sys");
     }
 }
 
@@ -1049,7 +1049,7 @@ static bool pxl8_script_is_builtin_global(const char* name) {
         "print", "pxl8", "rawequal", "rawget", "rawset", "require",
         "select", "setfenv", "setmetatable", "string", "table",
         "tonumber", "tostring", "type", "unpack", "update", "frame",
-        "xpcall", "_pxl8_gfx", "_pxl8_input", "_pxl8_rng", "_pxl8_sfx_mixer", "_pxl8_sys",
+        "xpcall", "pxl8_gfx", "pxl8_input", "pxl8_rng", "pxl8_sfx", "pxl8_sys",
         NULL
     };
     for (int i = 0; builtins[i]; i++) {