sdl alpha test

1 files changed, 46 insertions, 0 deletions

diff --git a/tests/sdl_canvas_alpha.c b/tests/sdl_canvas_alpha.c
new file mode 100644
index 00000000..1a41d115
--- /dev/null
+++ b/tests/sdl_canvas_alpha.c
@@ -0,0 +1,46 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <SDL/SDL.h>
+#include <SDL/SDL_ttf.h>
+#include <emscripten.h>
+
+
+int main(int argc, char **argv) {
+  SDL_Init(SDL_INIT_VIDEO);
+  SDL_Surface *screen = SDL_SetVideoMode(600, 450, 32, SDL_HWSURFACE);
+
+  printf("Init: %d\n", TTF_Init());
+
+  TTF_Font *font = TTF_OpenFont("sans-serif", 40);
+  printf("Font: %p\n", font);
+
+  SDL_Color color = { 0xff, 0x99, 0x00, 0xff };
+  SDL_Surface *text = TTF_RenderText_Solid(font, "hello orange world", color);
+
+  // render
+  for (int i = 0; i < 255; i++) {
+    SDL_Rect dest = { i, i, 0, 0 };
+    SDL_SetAlpha(text, 0, (((float)i)/255)*(((float)i)/255)*255);
+    SDL_BlitSurface (text, NULL, screen, &dest);
+  }
+
+  SDL_Flip(screen); 
+
+  SDL_LockSurface(screen);
+
+  int width, height, isFullscreen;
+  emscripten_get_canvas_size(&width, &height, &isFullscreen);
+
+  if (width != 600 && height != 450)
+  {
+    printf("error: wrong width/height\n");
+    abort();
+  }
+
+  SDL_Quit();
+
+  printf("done.\n");
+
+  return 0;
+}
+