diff --git a/docs/todos.md b/docs/todos.md index 825dbbd..37671cc 100644 --- a/docs/todos.md +++ b/docs/todos.md @@ -40,4 +40,19 @@ - [x] Parse individual instructions from binary CHIP-8 file - [x] Print all instructions from CHIP-8 file - [x] Write all CHIP-8 IBM logo opcodes to CSV file -- [ ] Implement opcodes present in the IMB logo CHIP-8 file +- [x] Implement opcodes present in the IMB logo CHIP-8 file + + | x | Opcode | Type | Description | + |---|--------|------|------------------------------| + | x | `00E0` | 00E0 | Clear display | + | x | `1nnn` | 1nnn | Jump to address | + | x | `3xkk` | 3xkk | Skip next if Vx == kk | + | x | `6xkk` | 6xkk | Load register with immediate | + | x | `7xkk` | 7xkk | Add immediate to Vx | + | x | `ANNN` | ANNN | Set index register | + | x | `Bnnn` | Bnnn | Jump to V0 + addr | + | x | `Dxyn` | Dxyn | Draw sprite | + +- [ ] Migrate drawing to raylib window +- [ ] Implement remaining instructions +- [ ] Handle keyboard input diff --git a/main.c b/main.c index 651ba7c..6a6e683 100644 --- a/main.c +++ b/main.c @@ -5,11 +5,14 @@ #include #include #include +#include #define MEMORY_SIZE 4096 #define PROGRAM_START 512 #define CPU_CLOCK_HZ 600 #define TIMER_HZ 60 +#define SCREEN_WIDTH 64 +#define SCREEN_HEIGHT 32 const int CYCLES_PER_FRAME = CPU_CLOCK_HZ / TIMER_HZ; @@ -32,8 +35,11 @@ enum ExitCodes { typedef struct ChipEight { uint8_t memory[MEMORY_SIZE]; uint16_t pc; + uint16_t I; + uint8_t V[16]; uint8_t dt; uint8_t st; + uint32_t display[SCREEN_WIDTH * SCREEN_HEIGHT]; } chip_eight_t; void println(const char *format, ...) { @@ -59,6 +65,25 @@ long get_time() { return ms; } +void draw(chip_eight_t *chip) { + printf("\033[J\033[H\033[?25l"); + + for (int i = 0; i < SCREEN_HEIGHT; i++) { + for (int j = 0; j < SCREEN_WIDTH; j++) { + uint32_t screen_pixel = chip->display[i * SCREEN_WIDTH + j]; + + if (screen_pixel == 1) { + printf("█"); + } else { + printf(" "); + } + } + + printf("\n"); + } + +} + int main(int argc, char *argv[]) { // Sets up Ctrl+C handling signal(SIGINT, handle_sigint); @@ -108,21 +133,12 @@ int main(int argc, char *argv[]) { chip->pc = PROGRAM_START; chip->dt = 0; chip->st = 0; + memset(chip->display, 0, sizeof(chip->display)); println("File '%s' loaded successfully", file_path); fclose(file_ptr); - FILE *csv_file_ptr = fopen("./imb_logo_opcodes.csv", "a"); - - if (csv_file_ptr == NULL) { - println("Failed to open csv file for writing"); - return -1; - } - - char *csv_headers = "opcode,nnn,n,x,y,kk\n"; - fprintf(csv_file_ptr, csv_headers); - // main loop while(keep_running) { if (chip->pc > MEMORY_SIZE) { @@ -164,14 +180,14 @@ int main(int argc, char *argv[]) { // oper: >> 8 // oper: & // mask: 00001111 00000000 (3840) - uint16_t x = (opcode >> 8) & 3840; + uint16_t x = (opcode & 3840) >> 8; // y - A 4-bit value, the upper 4 bits of the low byte of the instruction // i.e. 00000000 11110000 // oper: >> 4 // oper: & // mask: 00000000 11110000 (240) - uint16_t y = (opcode >> 4) & 240; + uint16_t y = (opcode & 240) >> 4; // kk or byte - An 8-bit value, the lowest 8 bits of the instruction // i.e. 00000000 11111111 @@ -179,33 +195,96 @@ int main(int argc, char *argv[]) { // mask: 00000000 11111111 (255) uint16_t kk = opcode & 255; - // write headers of variable name to .csv file - // create a string for each opcode that is comma separated - // then write that string into a .csv file - - char *csv_format = "%x,%d,%d,%d,%d,%d\n"; - int len_of_str = snprintf(NULL, 0, csv_format, opcode, nnn, n, x, y, kk); - char *csv_str = malloc((len_of_str + 1) * sizeof(char)); + // mask: 11110000 00000000 + switch(opcode & 61440) { + // Clear display (00E0) + case 0: + if (opcode == 224) { + // println("Clean the display"); + memset(chip->display, 0, sizeof(chip->display)); + draw(chip); + } + break; + case 4096: + // println("Jump to address: %d", nnn); + chip->pc = nnn; + break; + case 12288: + // println("Skip next"); - if (csv_str == NULL) { - println("Failed to allocate memory for csv string"); - return -1; + if (chip->V[x] == kk) { + // println("Skipping"); + chip->pc += 2; + } else { + // println("Not skipping"); + } + + break; + case 24576: + // println("Load register with immedate"); + chip->V[x] = kk; + break; + case 28672: + // println("Add immedate"); + chip->V[x] += kk; + break; + case 40960: + // println("Set index register"); + chip->I = nnn; + break; + case 45056: + // println("Jump to V0 + addr"); + chip->pc = nnn + chip->V[0]; + break; + case 53248: + // println("Draw sprite"); + uint8_t x_coordinate = chip->V[x] % SCREEN_WIDTH; + uint8_t y_coordinate = chip->V[y] % SCREEN_HEIGHT; + chip->V[15] = 0; + + for (int row = 0; row < n; row++) { + uint8_t sprite_byte = chip->memory[chip->I + row]; + + if ((y_coordinate + row) >= SCREEN_HEIGHT) { + break; + } + + for (int col = 0; col < 8; col++) { + if ((x_coordinate + col) >= SCREEN_WIDTH) { + break; + } + + // 0 0 0 0 0 0 0 0 + // 1 0 0 0 0 0 0 0 + // 0 1 0 0 0 0 0 0 + // 0 0 1 0 0 0 0 0 + uint8_t sprite_pixel = sprite_byte & (128 >> col); + + // **** + // **x* + int sprite_screen_index = ((y_coordinate + row) * SCREEN_WIDTH) + (x_coordinate + col); + uint32_t *screen_pixel = &chip->display[sprite_screen_index]; + + if (sprite_pixel != 0) { + if (*screen_pixel == 1) { + chip->V[15] = 1; + } + + *screen_pixel ^= 1; + } + } + } + + + draw(chip); + break; + default: + // println("Unhandled opcode: %x", opcode); + break; } - - snprintf(csv_str, len_of_str + 1, csv_format, opcode, nnn, n, x, y, kk); - fprintf(csv_file_ptr, csv_str); - - free(csv_str); - csv_str = NULL; - - println("opcode: %d", opcode); - println("nnn : %d", nnn); - println("n : %d", n); - println("x : %d", x); - println("y : %d", y); - println("kk : %d", kk); } + if (chip->dt > 0) { chip->dt--; } @@ -226,8 +305,6 @@ int main(int argc, char *argv[]) { } } - fclose(csv_file_ptr); - free(chip); return COMPLETED_SUCCESSFULLY;