From 533b50eafe05b41253cc5d33a1f239d2753f3d00 Mon Sep 17 00:00:00 2001 From: Juan Manuel Tomas Date: Sat, 15 Jan 2022 04:12:24 -0300 Subject: Fix application of mask to foreground --- main.c | 29 +++++++++++++++++++---------- 1 file changed, 19 insertions(+), 10 deletions(-) (limited to 'main.c') diff --git a/main.c b/main.c index e629966..260328c 100644 --- a/main.c +++ b/main.c @@ -12,10 +12,8 @@ SDL_Texture *createTiledTexture(SDL_Renderer *context, const char *filename) { int tile_h = texture_surface->h; SDL_FreeSurface(texture_surface); - Uint32 pixelformat; - SDL_QueryTexture(texture_tile, &pixelformat, 0, 0, 0); SDL_Texture *texture = SDL_CreateTexture(context, - pixelformat, + SDL_PIXELFORMAT_RGBA8888, SDL_TEXTUREACCESS_STATIC | SDL_TEXTUREACCESS_TARGET, WINDOW_W, WINDOW_H); SDL_SetRenderTarget(context, texture); @@ -47,19 +45,34 @@ int main() { SDL_Texture *background = createTiledTexture(context, "background.bmp"); SDL_Texture *foreground = createTiledTexture(context, "foreground.bmp"); + SDL_SetTextureBlendMode(foreground, SDL_BLENDMODE_BLEND); SDL_Surface *mask_surface = SDL_CreateRGBSurfaceWithFormat(0, WINDOW_W, WINDOW_H, 32, SDL_PIXELFORMAT_RGBA8888); SDL_LockSurface(mask_surface); for (int i = 0; i < mask_surface->w * mask_surface->h; i++) { - ((Uint32 *)mask_surface->pixels)[i] = 0x000000ff; + ((Uint32 *)mask_surface->pixels)[i] = 0x00000000; } - for (int i = 0; i < mask_surface->w * 50; i++) { + for (int i = mask_surface->w * 500; i < mask_surface->w * mask_surface->h; i++) { ((Uint32 *)mask_surface->pixels)[i] = 0xffffffff; } SDL_UnlockSurface(mask_surface); - SDL_Texture *terrain_texture = SDL_CreateTextureFromSurface(context, mask_surface); + + SDL_Texture *terrain = SDL_CreateTextureFromSurface(context, mask_surface); + + SDL_BlendMode true_mul = SDL_ComposeCustomBlendMode( + SDL_BLENDFACTOR_ZERO, + SDL_BLENDFACTOR_SRC_COLOR, + SDL_BLENDOPERATION_ADD, + SDL_BLENDFACTOR_ONE, + SDL_BLENDFACTOR_ZERO, + SDL_BLENDOPERATION_ADD); + SDL_SetTextureBlendMode(terrain, true_mul); + + SDL_SetRenderTarget(context, foreground); + SDL_RenderCopy(context, terrain, 0, 0); + SDL_SetRenderTarget(context, 0); int exit = 0; while (!exit) { @@ -70,10 +83,6 @@ int main() { } } SDL_RenderCopy(context, background, 0, 0); - SDL_SetRenderTarget(context, foreground); - SDL_SetTextureBlendMode(terrain_texture, SDL_BLENDMODE_MUL); - SDL_RenderCopy(context, terrain_texture, 0, 0); - SDL_SetRenderTarget(context, 0); SDL_RenderCopy(context, foreground, 0, 0); SDL_RenderPresent(context); -- cgit v1.2.3