Less buggy PPU

CMakeLists.txt

@@ -3,6 +3,10 @@ set(CMAKE_C_COMPILER gcc)
 cmake_minimum_required(VERSION 3.10)
 project(nes_emulator LANGUAGES C VERSION 0.1 )
 
+if (NES_DEBUG)
+    add_definitions(-DDEBUG=1)
+endif(NES_DEBUG)
+
 add_subdirectory(libs/log.c)
 set(CMAKE_MODULE_PATH ${PROJECT_SOURCE_DIR}/cmake)
 include_directories(${PROJECT_SOURCE_DIR}/libs/log.c/src ${COMMON_INCLUDES})
@@ -11,7 +15,6 @@ add_subdirectory(cpu)
 add_subdirectory(ppu)
 add_subdirectory(mappers)
 add_subdirectory(rom)
-#add_subdirectory(debugger)
 add_subdirectory(utils)
 add_subdirectory(gui)
 

README.md

@@ -37,6 +37,7 @@ only tested on Linux. Here is how to run the project:
 - Debug
    - Frame Delay: Done
    - Pattern Table Viewer: Done
+   - Nametable Viewer: Done
    - CPU Debugger: To Do
    - Memory Inspector: To Do
    - PPU Debugger: To Do

gui/CMakeLists.txt

@@ -1,5 +1,10 @@
-set(HEADERS canvas.h gui.h window.h main_window.h char_map.h pattern_display.h pattern_window.h nametable_window.h dbg_pattern_table.h dbg_nametable.h)
-set(SOURCE canvas.c gui.c window.c main_window.c char_map.c pattern_display.c pattern_window.c nametable_window.c dbg_pattern_table.c dbg_nametable.c)
+set(HEADERS gui.h window.h main_window.h)
+set(SOURCE gui.c window.c main_window.c)
+
+if (NES_DEBUG)
+    list(APPEND HEADERS char_map.h pattern_window.h nametable_window.h dbg_pattern_table.h dbg_nametable.h)
+    list(APPEND SOURCE char_map.c pattern_window.c nametable_window.c dbg_pattern_table.c dbg_nametable.c)
+endif (NES_DEBUG)
 
 add_library(nes_gui ${SOURCE} ${HEADERS})
 

gui/canvas.c

@@ -1,50 +0,0 @@
-//
-// Created by william on 16/05/24.
-//
-
-#include <assert.h>
-#include <string.h>
-#include <stdlib.h>
-#include "canvas.h"
-
-Canvas canvas_init(int width, int height) {
-    assert(width > 0);
-    assert(height > 0);
-
-    Canvas canvas;
-    canvas.width = width;
-    canvas.height = height;
-
-    int size = width * height;
-    canvas.pixels = malloc(sizeof(Pixel) * size);
-
-    return canvas;
-}
-
-void canvas_uninit(Canvas *canvas) {
-    assert(canvas != NULL);
-    assert(canvas->pixels != NULL);
-
-    free(canvas->pixels);
-}
-
-void canvas_draw(Canvas *canvas, Pixel pixel, int index) {
-    assert(index >= 0);
-    assert(index < canvas->width * canvas->height);
-
-    canvas->pixels[index] = pixel;
-}
-
-void canvas_draw_pos(Canvas *canvas, Pixel pixel, int x, int y) {
-    assert(x >= 0);
-    assert(x < canvas->width);
-    assert(y >= 0);
-    assert(y < canvas->height);
-
-    int index = x + y * canvas->width;
-    canvas_draw(canvas, pixel, index);
-}
-
-void canvas_reset(Canvas *canvas) {
-    memset(canvas->pixels, 0, sizeof(Pixel) * (canvas->width * canvas->height));
-}

gui/canvas.h

@@ -1,29 +0,0 @@
-//
-// Created by william on 16/05/24.
-//
-
-#ifndef NES_EMULATOR_CANVAS_H
-#define NES_EMULATOR_CANVAS_H
-
-#include "../include/types.h"
-
-typedef struct pixel {
-    byte r;
-    byte g;
-    byte b;
-} Pixel;
-
-typedef struct canvas {
-    int width;
-    int height;
-    Pixel *pixels;
-} Canvas;
-
-Canvas canvas_init(int width, int height);
-void canvas_uninit(Canvas *canvas);
-
-void canvas_draw(Canvas *canvas, Pixel pixel, int index);
-void canvas_draw_pos(Canvas *canvas, Pixel pixel, int x, int y);
-void canvas_reset(Canvas *canvas);
-
-#endif //NES_EMULATOR_CANVAS_H

gui/gui.c

@@ -11,6 +11,7 @@
 #include "nametable_window.h"
 #include "dbg_pattern_table.h"
 #include "dbg_nametable.h"
+#include "char_map.h"
 
 typedef struct nes_gui {
     NesMainWindow main_window;
@@ -19,11 +20,12 @@ typedef struct nes_gui {
 
     TTF_Font *font;
 
-    // Debug info
-    bool debug_enabled;
     Uint32 last_frame_tick;
     Uint32 frame_delay;
+
+#if DEBUG
     unsigned long tick;
+#endif
 } NesGui;
 NesGui gui;
 
@@ -35,15 +37,15 @@ bool gui_init() {
         return false;
     }
 
-    gui.debug_enabled = true;
+#if DEBUG
     gui.tick = 0;
+    pattern_window_init(&gui.pattern_window);
+    nametable_window_init(&gui.nametable_window);
 
-    main_window_init(&gui.main_window, gui.font);
+    char_map_init(gui.main_window.sdl_context.renderer, gui.font);
+#endif
 
-    if (gui.debug_enabled) {
-        pattern_window_init(&gui.pattern_window);
-        nametable_window_init(&gui.nametable_window);
-    }
+    main_window_init(&gui.main_window);
 
     return true;
 }
@@ -51,22 +53,24 @@ bool gui_init() {
 void gui_uninit() {
     main_window_uninit(&gui.main_window);
 
-    if (gui.debug_enabled) {
-        pattern_window_uninit(&gui.pattern_window);
-        nametable_window_uninit(&gui.nametable_window);
-    }
+#if DEBUG
+    char_map_uninit();
+
+    pattern_window_uninit(&gui.pattern_window);
+    nametable_window_uninit(&gui.nametable_window);
+#endif
 
     TTF_CloseFont(gui.font);
 }
 
 void gui_post_sysinit() {
-    if (gui.debug_enabled) {
-        dbg_pattern_table_init();
-        dbg_nametable_init();
+#if DEBUG
+    dbg_pattern_table_init();
+    dbg_nametable_init();
 
-        pattern_window_build_table(&gui.pattern_window);
-        nametable_window_update(&gui.nametable_window);
-    }
+    pattern_window_build_table(&gui.pattern_window);
+    nametable_window_update(&gui.nametable_window);
+#endif
 }
 
 int gui_input() {
@@ -82,27 +86,25 @@ int gui_input() {
 }
 
 void gui_render() {
-    main_window_render(&gui.main_window, ppu_get_state()->pixels);
+#if DEBUG
+    pattern_window_render(&gui.pattern_window);
 
-    if (gui.debug_enabled) {
-        pattern_window_render(&gui.pattern_window);
-
-//        if (gui.tick % 60 == 0) {
-            nametable_window_update(&gui.nametable_window);
-//        }
-        nametable_window_render(&gui.nametable_window);
-    }
+    nametable_window_update(&gui.nametable_window);
+    nametable_window_render(&gui.nametable_window);
 
     gui.tick++;
+#endif
+
+    main_window_render(&gui.main_window, ppu_get_state()->pixels);
 }
 
 void gui_present() {
-    main_window_present(&gui.main_window);
+#if DEBUG
+    pattern_window_present(&gui.pattern_window);
+    nametable_window_present(&gui.nametable_window);
+#endif
 
-    if (gui.debug_enabled) {
-        pattern_window_present(&gui.pattern_window);
-        nametable_window_present(&gui.nametable_window);
-    }
+    main_window_present(&gui.main_window);
 }
 
 void gui_delay() {
@@ -118,10 +120,6 @@ void gui_delay() {
     gui.last_frame_tick = SDL_GetTicks();
 }
 
-bool gui_debug_enabled() {
-    return gui.debug_enabled;
-}
-
 unsigned int gui_get_frame_delay() {
     return gui.frame_delay;
 }

gui/gui.h

@@ -6,7 +6,6 @@
 #define NES_EMULATOR_GUI_H
 
 #include <stdbool.h>
-#include "canvas.h"
 
 bool gui_init();
 void gui_uninit();
@@ -18,7 +17,6 @@ void gui_render();
 void gui_present();
 void gui_delay();
 
-bool gui_debug_enabled();
 unsigned int gui_get_frame_delay();
 
 #endif //NES_EMULATOR_GUI_H

gui/main_window.c

@@ -8,20 +8,18 @@
 #include "char_map.h"
 #include "gui.h"
 
-void main_window_init(NesMainWindow *window, TTF_Font *font) {
+void main_window_init(NesMainWindow *window) {
     window->sdl_context = window_init("NES Emulator", MAIN_WINDOW_WIDTH, MAIN_WINDOW_HEIGHT, MAIN_WINDOW_SCALE);
     window->texture = SDL_CreateTexture(window->sdl_context.renderer, SDL_PIXELFORMAT_ARGB8888,
                                         SDL_TEXTUREACCESS_STREAMING, MAIN_WINDOW_WIDTH, MAIN_WINDOW_HEIGHT);
-    char_map_init(window->sdl_context.renderer, font);
 }
 
 void main_window_uninit(NesMainWindow *window) {
-    char_map_uninit();
-
     SDL_DestroyTexture(window->texture);
     window_uninit(window->sdl_context);
 }
 
+#if DEBUG
 void main_window_render_delay(SDL_Renderer *renderer) {
     Uint32 delay = gui_get_frame_delay();
 
@@ -34,12 +32,12 @@ void main_window_render_delay(SDL_Renderer *renderer) {
 
     char_map_render(renderer, buffer);
 }
+#endif
 
 void main_window_render(NesMainWindow *window, PPUPixel *pixels) {
     SDL_RenderClear(window->sdl_context.renderer);
 
     unsigned int frame_buffer[240 * 256];
-
     for (int i = 0; i < 240 * 256; i++) {
         PPUPixel pixel = pixels[i];
 
@@ -53,9 +51,9 @@ void main_window_render(NesMainWindow *window, PPUPixel *pixels) {
     SDL_UpdateTexture(window->texture, NULL, &frame_buffer, 240 * sizeof(unsigned int));
     SDL_RenderCopy(window->sdl_context.renderer, window->texture, NULL, NULL);
 
-    if (gui_debug_enabled()) {
-        main_window_render_delay(window->sdl_context.renderer);
-    }
+#if DEBUG
+    main_window_render_delay(window->sdl_context.renderer);
+#endif
 }
 
 void main_window_present(NesMainWindow *window) {

gui/main_window.h

@@ -19,7 +19,7 @@ typedef struct nes_main_window {
     SDL_Texture *texture;
 } NesMainWindow;
 
-void main_window_init(NesMainWindow *window, TTF_Font *font);
+void main_window_init(NesMainWindow *window);
 void main_window_uninit(NesMainWindow *window);
 
 void main_window_render(NesMainWindow *window, PPUPixel* pixels);

gui/nametable_window.c

@@ -10,8 +10,7 @@
 #define NW_BUFFER_SIZE (NAMETABLE_ROW_WIDTH * NAMETABLE_COL_HEIGHT * PATTERN_DRAW_SIZE * PATTERN_DRAW_SIZE)
 
 void nametable_window_init(NesNametableWindow *window) {
-    int win_size = pattern_display_get_size(NW_ROW_TILE_COUNT);
-    window->sdl_context = window_init("Nametable", win_size, win_size, NW_SCALE);
+    window->sdl_context = window_init("Nametable", NW_WIDTH, NW_HEIGHT, NW_SCALE);
 
     window->texture = SDL_CreateTexture(window->sdl_context.renderer, SDL_PIXELFORMAT_ARGB8888,
                                         SDL_TEXTUREACCESS_STREAMING, NW_WIDTH, NW_HEIGHT);
@@ -22,7 +21,7 @@ void nametable_window_uninit(NesNametableWindow *window) {
     window_uninit(window->sdl_context);
 }
 
-void nametable_window_update_bank(NesNametableWindow *window, int bank, pixel* buffer) {
+void nametable_window_update_bank(NesNametableWindow *window, int bank, pixel *buffer) {
     dbg_nametable_render_bank(bank, buffer);
 
     SDL_Rect rect;

gui/nametable_window.h

@@ -7,7 +7,6 @@
 
 #include "window.h"
 #include "../include/types.h"
-#include "pattern_display.h"
 
 #define NW_SCALE 1
 #define NW_ROW_COUNT 60

gui/pattern_display.c

@@ -1,123 +0,0 @@
-//
-// Created by william on 12/07/24.
-//
-
-#include <assert.h>
-#include "pattern_display.h"
-
-#define PATTERN_BYTES (PATTERN_SIZE * 2)
-
-void pattern_display_init(PatternDisplay *display, SDL_Renderer *renderer, int tiles_x, int tiles_y, int display_type) {
-    assert(tiles_x > 0);
-    assert(tiles_y > 0);
-
-    display->width = tiles_x;
-    display->height = tiles_y;
-
-    display->texture = SDL_CreateTexture(renderer, SDL_PIXELFORMAT_ARGB8888, display_type,
-                                         pattern_display_get_size(tiles_x),
-                                         pattern_display_get_size(tiles_y));
-}
-
-void pattern_display_uninit(PatternDisplay *display) {
-    SDL_DestroyTexture(display->texture);
-}
-
-void pattern_display_draw_borders(unsigned int *buffer, int win_width, int win_height) {
-    assert(buffer != NULL);
-
-    for (int x = 0; x < win_width; x++) {
-        buffer[x] = PATTERN_BORDER_COLOR;
-    }
-
-    for (int y = 1; y < win_height; y++) {
-        buffer[y * win_width] = PATTERN_BORDER_COLOR;
-    }
-}
-
-void pattern_display_build_table(PatternTile *tile_table, int tile_count, read_func read_func,
-                                 void *read_func_data) {
-    for (int tile_index = 0; tile_index < tile_count; tile_index++) {
-        PatternTile *tile = &tile_table[tile_index];
-
-        address tile_addr = tile_index * PATTERN_BYTES;
-        memcpy(tile->data_low, read_func(tile_addr, read_func_data), 8);
-        memcpy(tile->data_high, read_func(tile_addr + 8, read_func_data), 8);
-    }
-}
-
-void pattern_display_draw_tile_borders(int tile_addr, pixel *buffer, int win_width) {
-    assert(buffer != NULL);
-
-    for (int by = 0; by < PATTERN_DRAW_SIZE; by++) {
-        address pixel_addr = tile_addr + (by * win_width) + PATTERN_DRAW_SIZE - 1;
-        buffer[pixel_addr] = PATTERN_BORDER_COLOR;
-    }
-
-    for (int bx = 0; bx < PATTERN_DRAW_SIZE; bx++) {
-        address pixel_addr = tile_addr + ((PATTERN_DRAW_SIZE - 1) * win_width) + bx;
-        buffer[pixel_addr] = PATTERN_BORDER_COLOR;
-    }
-}
-
-void pattern_display_draw_tile(PatternTile *tile, pixel *buffer, int tile_addr, int win_width) {
-    assert(buffer != NULL);
-
-    for (int fine_y = 0; fine_y < PATTERN_SIZE; fine_y++) {
-        byte data_high = tile->data_high[fine_y];
-        byte data_low = tile->data_low[fine_y];
-
-        for (int fine_x = 0; fine_x < PATTERN_SIZE; fine_x++) {
-            byte bitmask = 1 << (PATTERN_SIZE - fine_x - 1);
-            byte bit_high = data_high & bitmask;
-            byte bit_low = data_low & bitmask;
-
-            int pixel_addr = tile_addr + fine_x + fine_y * win_width;
-            pixel *pixel = &buffer[pixel_addr];
-
-            // TODO: Use palette colors
-            if (bit_high && bit_low) {
-                *pixel = 0xffffffff;
-            } else if (bit_low) {
-                *pixel = 0xffff0000;
-            } else if (bit_high) {
-                *pixel = 0xff00ffff;
-            } else {
-                *pixel = 0xff000000;
-            }
-        }
-    }
-
-    pattern_display_draw_tile_borders(tile_addr, buffer, win_width);
-}
-
-void pattern_display_build(PatternDisplay *display, read_func read_func, void *read_func_data) {
-    int tile_count = display->width * display->height;
-    PatternTile *tile_table = malloc(tile_count * sizeof(PatternTile));
-    pattern_display_build_table(tile_table, tile_count, read_func, read_func_data);
-
-    int win_width = pattern_display_get_size(display->width);
-    int win_height = pattern_display_get_size(display->height);
-    pixel *buffer = malloc(win_width * win_height * sizeof(pixel));
-
-    pattern_display_draw_borders(buffer, win_width, win_height);
-
-    for (int x = 0; x < display->width; x++) {
-        for (int y = 0; y < display->height; y++) {
-            PatternTile *tile = &tile_table[x + y * display->width];
-            address row_addr = (y * PATTERN_DRAW_SIZE + PATTERN_BORDER_WIDTH) * win_width;
-            address tile_addr = row_addr + (x * PATTERN_DRAW_SIZE + PATTERN_BORDER_WIDTH);
-
-            pattern_display_draw_tile(tile, buffer, tile_addr, win_width);
-        }
-    }
-
-    SDL_UpdateTexture(display->texture, NULL, buffer, win_width * sizeof(pixel));
-
-    free(tile_table);
-    free(buffer);
-}
-
-void pattern_display_render(PatternDisplay *display, SDL_Renderer *renderer) {
-    SDL_RenderCopy(renderer, display->texture, NULL, NULL);
-}

gui/pattern_display.h

@@ -1,47 +0,0 @@
-//
-// Created by william on 12/07/24.
-//
-
-#ifndef NES_EMULATOR_PATTERN_DISPLAY_H
-#define NES_EMULATOR_PATTERN_DISPLAY_H
-
-#include <SDL.h>
-#include "../include/types.h"
-
-#define PATTERN_DISPLAY_STATIC SDL_TEXTUREACCESS_STATIC
-#define PATTERN_DISPLAY_DYNAMIC SDL_TEXTUREACCESS_STREAMING
-
-#define PATTERN_SIZE 8
-#define PATTERN_BORDER_WIDTH 1
-#define PATTERN_BORDER_COLOR 0xff2223b2
-#define PATTERN_DRAW_SIZE (PATTERN_SIZE + PATTERN_BORDER_WIDTH)
-
-typedef unsigned int pixel;
-
-typedef byte *(*read_func)(address, void *);
-
-typedef struct pattern_tile {
-    byte data_low[8];
-    byte data_high[8];
-} PatternTile;
-
-typedef struct pattern_display {
-    SDL_Texture *texture;
-    PatternTile *tiles;
-    int width;
-    int height;
-} PatternDisplay;
-
-static inline int pattern_display_get_size(int tile_count) {
-    return tile_count * PATTERN_DRAW_SIZE + PATTERN_BORDER_WIDTH;
-}
-
-void pattern_display_init(PatternDisplay *display, SDL_Renderer *renderer, int tiles_x, int tiles_y, int display_type);
-
-void pattern_display_uninit(PatternDisplay *display);
-
-void pattern_display_build(PatternDisplay *display, read_func read_func, void *read_func_data);
-
-void pattern_display_render(PatternDisplay *display, SDL_Renderer *renderer);
-
-#endif //NES_EMULATOR_PATTERN_DISPLAY_H

gui/pattern_window.c

@@ -10,8 +10,7 @@
 #define PW_BUFFER_SIZE (PW_WIDTH * PW_HEIGHT)
 
 void pattern_window_init(NesPatternWindow *window) {
-    int win_width = pattern_display_get_size(PW_ROW_TILE_COUNT);
-    window->sdl_context = window_init("Pattern Table", win_width, win_width * 2, PW_SCALE);
+    window->sdl_context = window_init("Pattern Table", PW_WIDTH, PW_HEIGHT, PW_SCALE);
 
     window->texture = SDL_CreateTexture(window->sdl_context.renderer, SDL_PIXELFORMAT_ARGB8888,
                                         SDL_TEXTUREACCESS_STATIC, PW_WIDTH, PW_HEIGHT);

gui/pattern_window.h

@@ -7,14 +7,12 @@
 
 #include "../include/types.h"
 #include "window.h"
-#include "pattern_display.h"
 
 #define PW_SCALE 2
 #define PW_ROW_TILE_COUNT 16
 
 typedef struct nes_pattern_window {
     NesSdlContext sdl_context;
-    PatternDisplay pattern_display;
     SDL_Texture *texture;
 } NesPatternWindow;
 

main.c

@@ -24,6 +24,7 @@
 
 int main() {
     char *rom_path = "./test_roms/dk_jp.nes";
+//    char *rom_path = "./test_roms/nes-test-roms/other/BLOCKS.NES";
     log_set_level(LOG_INFO);
 
     if (!gui_init()) {

ppu/CMakeLists.txt

@@ -1,5 +1,5 @@
-set(HEADERS pattern_table.h ppu.h palette.h)
-set(SOURCE pattern_table.c ppu.c palette.c)
+set(HEADERS ppu.h palette.h)
+set(SOURCE ppu.c palette.c)
 
 add_library(nes_ppu ${SOURCE} ${HEADERS})
 

ppu/pattern_table.c

@@ -1,61 +0,0 @@
-//
-// Created by william on 17/05/24.
-//
-
-#include "pattern_table.h"
-#include "ppu.h"
-#include "../gui/canvas.h"
-#include "../gui/gui.h"
-
-inline void test() {
-
-}
-
-void pt_debug() {
-//    Canvas *canvas = gui_get_canvas(WINDOW_ID_PATTERN);
-//
-//    for (int palette = 0; palette < 2; palette++) {
-//        address palette_addr = palette * 0x1000;
-//        int palette_canvas_offset = palette * (PATTERN_TABLE_WIDTH * PATTERN_TILE_SIZE);
-//
-//        for (int y = 0; y < PATTERN_TABLE_WIDTH; y++) {
-//            for (int x = 0; x < PATTERN_TABLE_WIDTH; x++) {
-//                address tile_addr = palette_addr + (x + y * PATTERN_TABLE_WIDTH) * PATTERN_TILE_MEM_SIZE;
-//
-//                for (int tile_y = 0; tile_y < PATTERN_TILE_SIZE; tile_y++) {
-//                    byte p1_data = ppu_read(tile_addr + tile_y);
-//                    byte p2_data = ppu_read(tile_addr + tile_y + PATTERN_TILE_SIZE);
-//
-//                    for (int tile_x = 0; tile_x < PATTERN_TILE_SIZE; tile_x++) {
-//                        byte bitmask = 1 << (PATTERN_TILE_SIZE - tile_x - 1);
-//                        byte p1_byte = p1_data & bitmask;
-//                        byte p2_byte = p2_data & bitmask;
-//
-//                        Pixel pixel;
-//                        if (p1_byte && p2_byte) {
-//                            pixel.r = 255;
-//                            pixel.g = 255;
-//                            pixel.b = 255;
-//                        } else if (p2_byte) {
-//                            pixel.r = 255;
-//                            pixel.g = 0;
-//                            pixel.b = 0;
-//                        } else if (p1_byte) {
-//                            pixel.r = 0;
-//                            pixel.g = 255;
-//                            pixel.b = 255;
-//                        } else {
-//                            pixel.r = 0;
-//                            pixel.g = 0;
-//                            pixel.b = 0;
-//                        }
-//
-//                        int canvas_x = x * PATTERN_TILE_SIZE + tile_x;
-//                        int canvas_y = y * PATTERN_TILE_SIZE + tile_y + palette_canvas_offset;
-//                        canvas_draw_pos(canvas, pixel, canvas_x, canvas_y);
-//                    }
-//                }
-//            }
-//        }
-//    }
-}

ppu/pattern_table.h

@@ -1,14 +0,0 @@
-//
-// Created by william on 17/05/24.
-//
-
-#ifndef NES_EMULATOR_PATTERN_TABLE_H
-#define NES_EMULATOR_PATTERN_TABLE_H
-
-#define PATTERN_TABLE_WIDTH 16
-#define PATTERN_TILE_MEM_SIZE 16
-#define PATTERN_TILE_SIZE (PATTERN_TILE_MEM_SIZE / 2)
-
-void pt_debug();
-
-#endif //NES_EMULATOR_PATTERN_TABLE_H

ppu/ppu.c

@@ -19,7 +19,6 @@
 #include "../include/ppu.h"
 #include "../cpu/cpu.h"
 #include "../include/rom.h"
-#include "pattern_table.h"
 
 #define PPU_VISIBLE_FRAME_END 240
 #define PPU_POST_RENDER_LINE_START PPU_VISIBLE_FRAME_END
@@ -76,7 +75,7 @@ static inline unsigned int ppu_pixel_get_index(unsigned int scanline, unsigned i
 }
 
 static inline byte ppu_pixel_get_mask(unsigned int tile_fine_x) {
-    return 1 << (PATTERN_TILE_SIZE - tile_fine_x - 1);
+    return 1 << (8 - tile_fine_x - 1);
 }
 
 static inline void ppu_pixel_set_color(PPUPixel *pixel, byte pt_low, byte pt_high) {
@@ -110,7 +109,19 @@ static inline void ppu_pixel_set_color(PPUPixel *pixel, byte pt_low, byte pt_hig
 void ppu_draw_tile() {
     PPUTileFetch fetch = ppu_state.tile_queue.displayed_fetch;
 
-    unsigned int pixel_index = ppu_state.scanline * PPU_VISIBLE_FRAME_END + ppu_state.cycle;
+    unsigned int y = ppu_state.scanline;
+    unsigned int x = ppu_state.cycle + 0;
+
+//    if (x > PPU_LINE_WIDTH) {
+//        x -= PPU_LINE_WIDTH;
+//        y++;
+//    }
+//
+//    if (y > PPU_PRE_RENDER_LINE) {
+//        y -= PPU_PRE_RENDER_LINE;
+//    }
+
+    unsigned int pixel_index = y * PPU_VISIBLE_FRAME_END + x;
     PPUPixel *pixel = &ppu_state.pixels[pixel_index];
     ppu_pixel_set_color(pixel, fetch.pattern_table_tile_low, fetch.pattern_table_tile_high);
 }
@@ -121,7 +132,7 @@ byte ppu_get_pattern(byte tile_index, byte high) {
     return ppu_read(pattern_addr);
 }
 
-void ppu_fetch_tile() {
+void ppu_fetch_tile(bool render) {
     byte fetch_cycle = (ppu_state.cycle - 1) % 8;
 
     if (fetch_cycle == 1) {
@@ -151,7 +162,10 @@ void ppu_fetch_tile() {
     } else if (fetch_cycle == 7) {
         ppu_state.fetch.pattern_table_tile_high = ppu_get_pattern(ppu_state.fetch.nametable, 1);
         ppu_state.tile_queue.displayed_fetch = ppu_state.fetch;
-        ppu_draw_tile();
+
+        if (render) {
+            ppu_draw_tile();
+        }
 
         if ((ppu_state.ppu_address & 0x1f) == 0x1f) {
             ppu_state.ppu_address &= ~0x1f;
@@ -160,31 +174,6 @@ void ppu_fetch_tile() {
             ppu_state.ppu_address++;
         }
     }
-
-//    address read_addr;
-//    switch (fetch_cycle) {
-//        case 1:
-//            read_addr = 0x2000 + ((ppu_state.scanline / 8) * 0x20) + (ppu_state.cycle / 8);
-//            ppu_state.fetch.nametable = ppu_read(read_addr);
-//            break;
-//        case 3:
-//            read_addr = 0x23c0 + (ppu_state.cycle % 8);
-//            ppu_state.fetch.attribute_table = ppu_read(read_addr);
-//            break;
-//        case 5:
-//            read_addr = 0x1000 * ppu_read_flag(PPU_REGISTER_CTRL, PPU_CTRL_BG_PATTERN_TABLE_ADDR);
-//            read_addr += ppu_state.fetch.nametable * 16 + ppu_state.scanline % 8;
-//            ppu_state.fetch.pattern_table_tile_low = ppu_read(read_addr);
-//            break;
-//        case 7:
-//            read_addr = 0x1000 * ppu_read_flag(PPU_REGISTER_CTRL, PPU_CTRL_BG_PATTERN_TABLE_ADDR);
-//            read_addr += ppu_state.fetch.nametable * 16 + ppu_state.scanline % 8 + 8;
-//            ppu_state.fetch.pattern_table_tile_high = ppu_read(read_addr);
-//            ppu_tile_push();
-//            break;
-//        default:
-//            break;
-//    }
 }
 
 void ppu_visible_frame(unsigned int cycle) {
@@ -195,8 +184,8 @@ void ppu_visible_frame(unsigned int cycle) {
 
     if (cycle == 0) {
         // Idle...
-    } else if (cycle <= 256) {
-        ppu_fetch_tile();
+    } else if (cycle >= 8 && cycle <= 256) {
+        ppu_fetch_tile(true);
 
         if (cycle == 256) {
             if ((ppu_state.ppu_address & 0x7000) != 0x7000) {
@@ -208,7 +197,7 @@ void ppu_visible_frame(unsigned int cycle) {
                     ppu_state.ppu_address += 0x20;
                 } else {
                     ppu_state.ppu_address &= ~0x3e0;
-//                    ppu_state.ppu_address ^= 0x0800;
+                    ppu_state.ppu_address ^= 0x0800;
                 }
             }
         }
@@ -220,8 +209,8 @@ void ppu_visible_frame(unsigned int cycle) {
             ppu_state.ppu_address = (ppu_state.ppu_address & 0xfbe0) | (ppu_state.temp_ppu_addr & ~0xfbe0);
             ppu_state.x_scroll = 0;
         }
-    } else if (cycle <= 336) {
-        ppu_fetch_tile();
+    } else if (cycle <= 328) {
+        ppu_fetch_tile(false);
     }
 }
 
@@ -262,8 +251,8 @@ void ppu_cycle() {
     if (rendering_enabled && ppu_state.odd_frame) {
         // With rendering enabled, the odd frames are shorter
         // TODO: and doing the last cycle of the last dummy nametable fetch there instead
-        frame_width = PPU_LINE_WIDTH - 2;
-        frame_height = PPU_LINE_END - 1;
+//        frame_width = PPU_LINE_WIDTH - 2;
+//        frame_height = PPU_LINE_END - 1;
     }
 
     ppu_state.cycle++;

system.c

@@ -5,10 +5,7 @@
 #include "include/cpu.h"
 #include "include/system.h"
 #include "memory.h"
-#include <unistd.h>
-#include <assert.h>
 #include "cpu.h"
-#include "pattern_table.h"
 
 System current_sys;
 
@@ -33,8 +30,6 @@ void system_next_frame() {
             ppu_cycle();
         }
     }
-
-    pt_debug();
 }
 
 void system_uninit() {