Canvas:newTextureData;

src/api/types/canvas.c

@@ -46,6 +46,18 @@ int l_lovrCanvasSetTexture(lua_State* L) {
   return 0;
 }
 
+int l_lovrCanvasNewTextureData(lua_State* L) {
+  Canvas* canvas = luax_checktype(L, 1, Canvas);
+  int index = luaL_optinteger(L, 2, 1) - 1;
+  int count;
+  lovrCanvasGetAttachments(canvas, &count);
+  lovrAssert(index >= 0 && index < count, "Can not create a TextureData from Texture #%d of Canvas (it only has %d textures)", index, count);
+  TextureData* textureData = lovrCanvasNewTextureData(canvas, index);
+  luax_pushobject(L, textureData);
+  lovrRelease(textureData);
+  return 1;
+}
+
 int l_lovrCanvasRenderTo(lua_State* L) {
   Canvas* canvas = luax_checktype(L, 1, Canvas);
   luaL_checktype(L, 2, LUA_TFUNCTION);
@@ -60,6 +72,7 @@ int l_lovrCanvasRenderTo(lua_State* L) {
 const luaL_Reg lovrCanvas[] = {
   { "getTexture", l_lovrCanvasGetTexture },
   { "setTexture", l_lovrCanvasSetTexture },
+  { "newTextureData", l_lovrCanvasNewTextureData },
   { "renderTo", l_lovrCanvasRenderTo },
   { NULL, NULL }
 };

src/graphics/canvas.h

@@ -36,3 +36,4 @@ void lovrCanvasBlit(Canvas* canvas);
 bool lovrCanvasIsStereo(Canvas* canvas);
 uint32_t lovrCanvasGetWidth(Canvas* canvas);
 uint32_t lovrCanvasGetHeight(Canvas* canvas);
+TextureData* lovrCanvasNewTextureData(Canvas* canvas, int index);

src/graphics/opengl.c

@@ -1452,6 +1452,28 @@ uint32_t lovrCanvasGetHeight(Canvas* canvas) {
   return canvas->height;
 }
 
+TextureData* lovrCanvasNewTextureData(Canvas* canvas, int index) {
+  lovrCanvasBind(canvas);
+
+  Texture* texture = canvas->attachments[index].texture;
+  if ((texture->incoherent >> BARRIER_TEXTURE) & 1) {
+    lovrGpuWait(1 << BARRIER_TEXTURE);
+  }
+
+  if (index != 0) {
+    glReadBuffer(index);
+  }
+
+  TextureData* textureData = lovrTextureDataCreate(canvas->width, canvas->height, 0x0, FORMAT_RGBA);
+  glReadPixels(0, 0, canvas->width, canvas->height, GL_RGBA, GL_UNSIGNED_BYTE, textureData->blob.data);
+
+  if (index != 0) {
+    glReadBuffer(0);
+  }
+
+  return textureData;
+}
+
 // Shader
 
 static GLuint compileShader(GLenum type, const char** sources, int count) {