Add palette switch to the debug pattern view.

README.md

@@ -8,6 +8,10 @@ only tested on Linux. Here is how to run the project:
  - Build the project with Make: ```make```
  - Run the emulator: ```./nes_emulator```
 
+## Controls
+ - `p`: Pauses the emulation
+ - `o`: Go to the next palette in the pattern viewer
+
 ## Dependencies
  - GCC compiler
  - CMake

gui/dbg_pattern_table.c

@@ -93,7 +93,7 @@ void dbg_pattern_draw_pos(int x, int y, int bank, pixel *buffer, int buffer_widt
     dbg_pattern_draw_pattern(pattern, buffer, buffer_width, palette);
 }
 
-void dbg_pattern_draw_bank(int bank, pixel *buffer) {
+void dbg_pattern_draw_bank(int bank, pixel *buffer, int palette) {
     int buffer_width = PATTERN_TABLE_WIDTH * PATTERN_DRAW_SIZE;
 
     for (int x = 0; x < PATTERN_TABLE_WIDTH; x++) {
@@ -101,7 +101,7 @@ void dbg_pattern_draw_bank(int bank, pixel *buffer) {
             address row_addr = (y * PATTERN_DRAW_SIZE) * buffer_width;
             address tile_addr = row_addr + (x * PATTERN_DRAW_SIZE);
 
-            dbg_pattern_draw_pos(x, y, bank, &buffer[tile_addr], buffer_width, 01);
+            dbg_pattern_draw_pos(x, y, bank, &buffer[tile_addr], buffer_width, palette);
         }
     }
 }

gui/dbg_pattern_table.h

@@ -78,7 +78,8 @@ void dbg_pattern_draw_pos(int x, int y, int bank, pixel *buffer, int buffer_widt
  * Draws a pattern bank to a buffer. Uses the palette #0.
  * @param bank The bank to draw (0 -> 0x0000, 1 -> 0x1000)
  * @param buffer The buffer to write the patterns data to.
+ * @param palette The background palette to use
  */
-void dbg_pattern_draw_bank(int bank, pixel *buffer);
+void dbg_pattern_draw_bank(int bank, pixel *buffer, int palette);
 
 #endif //NES_EMULATOR_DBG_PATTERN_TABLE_H

gui/gui.c

@@ -70,6 +70,7 @@ void gui_post_sysinit() {
     dbg_pattern_table_init();
     dbg_nametable_init();
 
+    // TODO: The texture is rendered before the palette data is in the PPU memory, so the only color is grey
     pattern_window_build_table(&gui.pattern_window);
     nametable_window_update(&gui.nametable_window);
 #endif
@@ -83,8 +84,14 @@ int gui_input() {
             return -1;
         }
 
-        if (event.type == SDL_KEYUP && event.key.keysym.sym == SDLK_p) {
+        if (event.type == SDL_KEYUP) {
+            if (event.key.keysym.sym == SDLK_p) {
                 system_toggle_pause();
+            } else {
+#if DEBUG
+                pattern_window_key_up(&gui.pattern_window, event.key.keysym.sym);
+#endif
+            }
         }
     }
 

gui/nametable_window.h

@@ -8,7 +8,7 @@
 #include "window.h"
 #include "../include/types.h"
 
-#define NW_SCALE 2
+#define NW_SCALE 1
 #define NW_ROW_COUNT 60
 #define NW_ROW_TILE_COUNT 64
 

gui/pattern_window.c

@@ -14,6 +14,7 @@ void pattern_window_init(NesPatternWindow *window) {
 
     window->texture = SDL_CreateTexture(window->sdl_context.renderer, SDL_PIXELFORMAT_ARGB8888,
                                         SDL_TEXTUREACCESS_STATIC, PW_WIDTH, PW_HEIGHT);
+    window->palette = 0;
 }
 
 void pattern_window_uninit(NesPatternWindow *window) {
@@ -23,12 +24,25 @@ void pattern_window_uninit(NesPatternWindow *window) {
 
 void pattern_window_build_table(NesPatternWindow *window) {
     pixel buffer[PW_BUFFER_SIZE] = {0};
-    dbg_pattern_draw_bank(PATTERN_BANK_0, buffer);
+    dbg_pattern_draw_bank(PATTERN_BANK_0, buffer, window->palette);
-    dbg_pattern_draw_bank(PATTERN_BANK_1, &buffer[PW_WIDTH * (PW_HEIGHT / 2)]);
+    dbg_pattern_draw_bank(PATTERN_BANK_1, &buffer[PW_WIDTH * (PW_HEIGHT / 2)], window->palette);
 
     SDL_UpdateTexture(window->texture, NULL, buffer, PW_WIDTH * sizeof(pixel));
 }
 
+void pattern_window_key_up(NesPatternWindow *window, SDL_KeyCode keycode) {
+    if (keycode != SDLK_o) {
+        return;
+    }
+
+    window->palette++;
+    if (window->palette > PW_PALETTE_MAX) {
+        window->palette = 0;
+    }
+
+    pattern_window_build_table(window);
+}
+
 void pattern_window_render(NesPatternWindow *window) {
     SDL_RenderClear(window->sdl_context.renderer);
     SDL_RenderCopy(window->sdl_context.renderer, window->texture, NULL, NULL);

gui/pattern_window.h

@@ -10,10 +10,12 @@
 
 #define PW_SCALE 2
 #define PW_ROW_TILE_COUNT 16
+#define PW_PALETTE_MAX 3
 
 typedef struct nes_pattern_window {
     NesSdlContext sdl_context;
     SDL_Texture *texture;
+    byte palette;
 } NesPatternWindow;
 
 void pattern_window_init(NesPatternWindow *window);
@@ -21,6 +23,7 @@ void pattern_window_uninit(NesPatternWindow *window);
 
 void pattern_window_build_table(NesPatternWindow *window);
 
+void pattern_window_key_up(NesPatternWindow *window, SDL_KeyCode keycode);
 void pattern_window_render(NesPatternWindow *window);
 void pattern_window_present(NesPatternWindow *window);
 

main.c

@@ -23,8 +23,8 @@
 #include "gui.h"
 
 int main() {
-//    char *rom_path = "./test_roms/dk_japan.nes";
+    char *rom_path = "./test_roms/dk_japan.nes";
-    char *rom_path = "./test_roms/smb.nes";
+//    char *rom_path = "./test_roms/smb.nes";
     log_set_level(LOG_INFO);
 
     if (!gui_init()) {