diff options
| -rw-r--r-- | main.c | 75 |
1 files changed, 55 insertions, 20 deletions
@@ -5,6 +5,15 @@ #define WINDOW_W 1280 #define WINDOW_H 720 +void renderMaskedTexture(SDL_Renderer *context, SDL_Texture *result, SDL_Texture *mask, SDL_Texture *diffuse) { + SDL_SetRenderTarget(context, result); + SDL_SetRenderDrawColor(context, 0, 0, 0, 0); + SDL_RenderClear(context); + SDL_RenderCopy(context, mask, 0, 0); + SDL_RenderCopy(context, diffuse, 0, 0); + SDL_SetRenderTarget(context, 0); +} + SDL_Texture *createTiledTexture(SDL_Renderer *context, const char *filename) { SDL_Surface *texture_surface = SDL_LoadBMP(filename); SDL_Texture *texture_tile = SDL_CreateTextureFromSurface(context, texture_surface); @@ -14,7 +23,7 @@ SDL_Texture *createTiledTexture(SDL_Renderer *context, const char *filename) { SDL_Texture *texture = SDL_CreateTexture(context, SDL_PIXELFORMAT_RGBA8888, - SDL_TEXTUREACCESS_STATIC | SDL_TEXTUREACCESS_TARGET, + SDL_TEXTUREACCESS_TARGET, WINDOW_W, WINDOW_H); SDL_SetRenderTarget(context, texture); for (int y = 0; y < WINDOW_H; y += tile_h) { @@ -40,16 +49,20 @@ int main() { SDL_Renderer *context = SDL_CreateRenderer(window, -1, SDL_RENDERER_ACCELERATED); - SDL_SetRenderDrawColor(context, 40, 40, 40, 255); - SDL_RenderClear(context); - SDL_Texture *background = createTiledTexture(context, "background.bmp"); + SDL_Texture *foreground = createTiledTexture(context, "foreground.bmp"); - SDL_SetTextureBlendMode(foreground, SDL_BLENDMODE_BLEND); + SDL_SetTextureBlendMode(foreground, SDL_BLENDMODE_MOD); SDL_Surface *mask_surface = SDL_CreateRGBSurfaceWithFormat(0, WINDOW_W, WINDOW_H, 32, SDL_PIXELFORMAT_RGBA8888); + SDL_Texture *terrain = SDL_CreateTexture(context, + SDL_PIXELFORMAT_RGBA8888, + SDL_TEXTUREACCESS_TARGET, + WINDOW_W, WINDOW_H); + SDL_SetTextureBlendMode(terrain, SDL_BLENDMODE_BLEND); + SDL_LockSurface(mask_surface); for (int i = 0; i < mask_surface->w * mask_surface->h; i++) { ((Uint32 *)mask_surface->pixels)[i] = 0x00000000; @@ -58,21 +71,9 @@ int main() { ((Uint32 *)mask_surface->pixels)[i] = 0xffffffff; } SDL_UnlockSurface(mask_surface); + SDL_Texture *mask_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); + renderMaskedTexture(context, terrain, mask_texture, foreground); int exit = 0; while (!exit) { @@ -82,8 +83,42 @@ int main() { exit = 1; } } + int mouse_x, mouse_y; + Uint32 mouse_state = SDL_GetMouseState(&mouse_x, &mouse_y); + if (mouse_state & SDL_BUTTON_LMASK) { + SDL_LockSurface(mask_surface); + unsigned size = 100; + for (int j = mouse_y - size / 2; j < mouse_y + size / 2; j++) { + for (int i = mouse_x - size / 2; i < mouse_x + size / 2; i++) { + size_t index = i + j * WINDOW_W; + ((Uint32 *)mask_surface->pixels)[index] = 0xffffffff; + } + } + SDL_UnlockSurface(mask_surface); + SDL_DestroyTexture(mask_texture); + mask_texture = SDL_CreateTextureFromSurface(context, mask_surface); + + renderMaskedTexture(context, terrain, mask_texture, foreground); + } else if (mouse_state & SDL_BUTTON_RMASK) { + SDL_LockSurface(mask_surface); + unsigned size = 100; + for (int j = mouse_y - size / 2; j < mouse_y + size / 2; j++) { + for (int i = mouse_x - size / 2; i < mouse_x + size / 2; i++) { + size_t index = i + j * WINDOW_W; + ((Uint32 *)mask_surface->pixels)[index] = 0x00000000; + } + } + SDL_UnlockSurface(mask_surface); + SDL_DestroyTexture(mask_texture); + mask_texture = SDL_CreateTextureFromSurface(context, mask_surface); + + renderMaskedTexture(context, terrain, mask_texture, foreground); + } + SDL_SetRenderDrawColor(context, 40, 40, 40, 255); + SDL_RenderClear(context); + SDL_RenderCopy(context, background, 0, 0); - SDL_RenderCopy(context, foreground, 0, 0); + SDL_RenderCopy(context, terrain, 0, 0); SDL_RenderPresent(context); SDL_Delay(10); |