Add CRT overlay effect

Makefile

@@ -54,7 +54,7 @@ SRC_SRCS_1 += overlay.c menu.c
 SRC_SRCS_1 += state.c ini.c
 SRC_SRCS_1 += compat.c
 SRC_SRCS_1 += sdl_render.c sdl_input.c sdl_audio.c sdl_timer.c
-SRC_SRCS_1 += sdl_overlay.c
+SRC_SRCS_1 += sdl_overlay.c sdl_effect.c
 
 PLAT_SRCS_1 = filemap.c
 

src/input.h

@@ -19,6 +19,7 @@ typedef enum {
     input_Result_View,
     input_Result_Refresh,
     input_Result_Scale,
+    input_Result_Effect,
 } nes_Input_Result;
 
 #define nes_controller_num_buttons  (8U)

src/menu.c

@@ -281,6 +281,8 @@ int run_game_menu(menu_state* state, nese_Components* comp,
 #endif
         (nese->flags & (1 << State_Bit_Integer_Scale)) ?
             "Force Aspect" : "Integer Scaling",
+        (nese->flags & (1 << State_Bit_CRT_Effect)) ?
+            "No Effect" : "CRT Effect",
         "Exit",
     };
     static const int choices[] = {
@@ -293,6 +295,7 @@ int run_game_menu(menu_state* state, nese_Components* comp,
         input_Result_View,
 #endif
         input_Result_Scale,
+        input_Result_Effect,
         input_Result_Quit,
     };
     const file_list options = {

src/nese.c

@@ -179,14 +179,17 @@ static int do_game_menu(menu_state* menu,
         status = run_game_menu(menu, comp, state);
 
         if (    input_Result_View == status ||
-                input_Result_Scale == status    ) {
+                input_Result_Scale == status ||
+                input_Result_Effect == status    ) {
             if (input_Result_View == status) {
 #ifndef STANDALONE
 
                 state->flags ^= (1 << State_Bit_Fullscreen);
 #endif
-            } else {
+            } else if (input_Result_Scale == status) {
                 state->flags ^= (1 << State_Bit_Integer_Scale);
+            } else {
+                state->flags ^= (1 << State_Bit_CRT_Effect);
             }
             nes_render_set_flags(comp->rend, state->flags);
             continue;

src/sdl_effect.c

@@ -0,0 +1,71 @@
+#include "sdl_effect.h"
+
+/*
+static const uint8_t the_effect[3][3][4] = {
+    {{14, 0, 216, 204}, {16, 0, 0, 217}, {21, 225, 1, 0},},
+    {{81, 0,   1,   1}, {83, 1, 0,   3}, {72,   2, 0, 0},},
+    {{ 5, 0, 252, 245}, { 6, 0, 0, 243}, {10, 236, 1, 0},},
+};
+
+static const int effect_w = 3;
+static const int effect_h = 3;
+*/
+
+static const uint8_t the_effect[2][2][4] = {
+    {{ 25, 0, 0, 0}, {  1, 0, 0, 0},},
+    {{144, 0, 0, 0}, {133, 0, 0, 0},},
+};
+
+static const int effect_w = 2;
+static const int effect_h = 2;
+
+
+sdl_effect* effect_init(SDL_Renderer* renderer,
+                        int view_w, int view_h) {
+    const int tex_w = view_w * 2;
+    const int tex_h = view_h * 2;
+
+    SDL_SetHint(SDL_HINT_RENDER_SCALE_QUALITY, "1");
+
+    SDL_Texture* effect = SDL_CreateTexture(
+            renderer, SDL_PIXELFORMAT_BGRA8888,
+            SDL_TEXTUREACCESS_STREAMING, tex_w, tex_h
+        );
+
+    void* pixels = NULL;
+    int pitch = 0;
+    SDL_LockTexture(effect, NULL, &pixels, &pitch);
+
+    uint8_t* dst_line = (uint8_t*)pixels;
+    for (int y = 0; y < tex_h; ++y) {
+        uint8_t* dst = dst_line;
+        for (int x = 0; x < tex_w; ++x) {
+            dst[0] = the_effect[y % effect_h][x % effect_w][0];
+            dst[1] = the_effect[y % effect_h][x % effect_w][1];
+            dst[2] = the_effect[y % effect_h][x % effect_w][2];
+            dst[3] = the_effect[y % effect_h][x % effect_w][3];
+            dst += 4;
+        }
+        dst_line += pitch;
+    }
+
+    SDL_UnlockTexture(effect);
+
+    SDL_SetTextureBlendMode(effect, SDL_BLENDMODE_BLEND);
+
+    return (sdl_effect*)effect;
+}
+
+void effect_done(sdl_effect* effect) {
+    if (effect) {
+        SDL_DestroyTexture((SDL_Texture*)effect);
+    }
+}
+
+void effect_apply(sdl_effect* effect, SDL_Renderer* renderer,
+                  const SDL_Rect* rect) {
+    if (effect) {
+        SDL_RenderCopy(renderer, (SDL_Texture*)effect,
+                       NULL, rect);
+    }
+}

src/sdl_effect.h

@@ -0,0 +1,17 @@
+#ifndef NESE_SDL_EFFECT_H_
+#define NESE_SDL_EFFECT_H_
+
+#include <SDL.h>
+
+
+typedef struct sdl_effect sdl_effect;
+
+
+sdl_effect* effect_init(SDL_Renderer*, int, int);
+
+void effect_done(sdl_effect*);
+
+void effect_apply(sdl_effect*, SDL_Renderer*, const SDL_Rect*);
+
+
+#endif // NESE_SDL_EFFECT_H_

src/sdl_render.c

@@ -7,6 +7,7 @@
 #include "mapper.h"
 #include "menu.h"
 #include "sdl_overlay.h"
+#include "sdl_effect.h"
 
 
 static SDL_Color nes_palette[64] = {
@@ -47,6 +48,8 @@ typedef struct {
 
     SDL_Texture* texture;
     SDL_Rect view;
+
+    struct sdl_effect* effect;
 } sdl_render_data;
 
 static sdl_render_data the_render_data = {0};
@@ -221,6 +224,11 @@ static int sdl_render_init(nes_Renderer* rend) {
     }
 
     if (0 == status) {
+        data->effect = effect_init(
+                data->renderer,
+                nes_ppu_render_w, nes_ppu_render_h
+            );
+
         SDL_SetPaletteColors(data->background->format->palette,
                              nes_palette, 0U, 64U);
         SDL_SetColorKey(data->background, SDL_TRUE, 0xFFU);
@@ -235,6 +243,7 @@ static int sdl_render_init(nes_Renderer* rend) {
 
 static void sdl_render_done(nes_Renderer* rend) {
     sdl_render_data* data = (sdl_render_data*)rend->data;
+    if (data->effect) effect_done(data->effect);
     overlay_done(&rend->overlay);
     sdl_overlay_font_done(&data->font);
     SDL_DestroyTexture(data->texture);
@@ -629,6 +638,11 @@ static int sdl_render(nes_Renderer* rend, nes_ppu* ppu) {
         SDL_LockTextureToSurface(data->texture, NULL,
                                  &data->target);
 
+        if (rend->flags & (1 << State_Bit_CRT_Effect)) {
+            effect_apply(data->effect, data->renderer,
+                         &data->view);
+        }
+
         sdl_overlay_frame(
                 &rend->overlay, &data->font, data->renderer,
                 data->view.x, data->view.y,
@@ -662,6 +676,10 @@ static void sdl_redraw_frame(nes_Renderer* rend, int dim) {
                    NULL, &data->view);
     SDL_LockTextureToSurface(data->texture, NULL, &data->target);
 
+    if (rend->flags & (1 << State_Bit_CRT_Effect)) {
+        effect_apply(data->effect, data->renderer, &data->view);
+    }
+
     if (dim) {
         SDL_SetTextureBlendMode(data->texture,
                                 SDL_BLENDMODE_NONE);

src/state.c

@@ -43,7 +43,7 @@ static const ini_datum prefs_schema = {
             .type = ini_section,
             .name = ".flags",
             .offset = offsetof(nese_State, flags),
-            .count = 2,
+            .count = 3,
             .data = (ini_datum[]){
                 {
                     .type = ini_flag,
@@ -53,6 +53,10 @@ static const ini_datum prefs_schema = {
                     .type = ini_flag,
                     .name = "integer_scale",
                     .shift = State_Bit_Integer_Scale,
+                }, {
+                    .type = ini_flag,
+                    .name = "crt_effect",
+                    .shift = State_Bit_CRT_Effect,
                 },
             }
         },

src/state.h

@@ -35,6 +35,7 @@ void cart_info_done(cart_info*);
 typedef enum {
     State_Bit_Fullscreen    = 0,
     State_Bit_Integer_Scale = 1,
+    State_Bit_CRT_Effect    = 2,
 } nese_State_Flag_Bits;
 
 typedef struct {