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Adding a gap buffer to a text editor
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#include <SDL2/SDL.h> | |
#include <stdio.h> | |
int error(char *msg, const char *err) { | |
printf("Error %s: %s\n", msg, err); | |
return 0; | |
} | |
#define HOR 32 | |
#define VER 16 | |
#define PAD 8 | |
#define TEXTSZ 1024 * 32 | |
char text[TEXTSZ+1]; | |
int text_len = 0; | |
int cursor = 0; | |
void pushchar(char c) { | |
int i; | |
if(text_len >= TEXTSZ) | |
return; | |
for(i = text_len-1; i >= cursor; --i) | |
text[i + 1] = text[i]; | |
text_len++; | |
text[cursor] = c; | |
cursor++; | |
} | |
void left() { | |
if(cursor > 0) --cursor; | |
} | |
void right() { | |
if(cursor < text_len-1) ++cursor; | |
} | |
int loadtxt(char *name) { | |
char line[256]; | |
FILE *f = fopen(name, "r"); | |
if(!f) return error("Load", "Invalid input file"); | |
text_len = 0; | |
while(fgets(line, 256, f)) { | |
int i = 0; | |
char c; | |
while((c = line[i++])) | |
pushchar(c); | |
} | |
/* reset cursor */ | |
cursor = 0; | |
printf("Loaded: %s\n", name); | |
fclose(f); | |
return 1; | |
} | |
int cursorcol() { | |
int result = 0; | |
int c; | |
for(c = cursor-1; c >= 0; --c) { | |
if(text[c] == '\n') break; | |
++result; | |
} | |
return result; | |
} | |
void down() { | |
int col = cursorcol(); | |
/* skip rest of line */ | |
for(; cursor < text_len && text[cursor] != '\n'; ++cursor) | |
right(); | |
/* scan forward on next line */ | |
right(); | |
for(; col > 0 && cursor < text_len && text[cursor] != '\n'; --col) | |
right(); | |
} | |
void up() { | |
int col = cursorcol(); | |
/* scan back to end of previous line */ | |
left(); | |
while(cursor > 0 && text[cursor] != '\n') | |
left(); | |
/* scan back to start of previous line */ | |
left(); | |
while(cursor > 0 && text[cursor] != '\n') | |
left(); | |
/* scan forward on previous line */ | |
for(; col > 0 && cursor < text_len && text[cursor] != '\n'; --col) | |
right(); | |
} | |
int WIDTH = 8 * HOR + PAD * 2; | |
int HEIGHT = 8 * (VER + 2) + PAD * 2; | |
int FPS = 30, GUIDES = 1, ZOOM = 2; | |
Uint8 chrbuf[2048]; | |
SDL_Window *gWindow = NULL; | |
SDL_Renderer *gRenderer = NULL; | |
SDL_Texture *gTexture = NULL; | |
Uint32 *pixels; | |
void clear(Uint32 *dst) { | |
int i, j; | |
for(i = 0; i < HEIGHT; i++) | |
for(j = 0; j < WIDTH; j++) | |
dst[i * WIDTH + j] = 0; | |
} | |
void putpixel(Uint32 *dst, int x, int y) { | |
if(x >= 0 && x < WIDTH - 8 && y >= 0 && y < HEIGHT - 8) | |
dst[(y + PAD) * WIDTH + (x + PAD)] = 0xffffffff; | |
} | |
void drawletter(Uint32 *dst, int x, int y, int id) { | |
int v, h, offset = id * 16; | |
for(v = 0; v < 8; v++) | |
for(h = 0; h < 8; h++) { | |
int px = (x * 8) + (8 - h); | |
int py = (y * 8) + v; | |
int ch1 = chrbuf[offset + v]; | |
int ch2 = chrbuf[offset + v + 8]; | |
int clr = ((ch1 >> h) & 0x1) + (((ch2 >> h) & 0x1) << 1); | |
if(clr) | |
putpixel(dst, px, py); | |
} | |
} | |
void drawbody(Uint32 *dst) { | |
int i, x = 0, line = 0; | |
for(i = 0; i < text_len; ++i) { | |
char c = text[i]; | |
drawletter(dst, x, line, (int)c); | |
x++; | |
if(c == '\n') { | |
x = 0; | |
line++; | |
} | |
} | |
} | |
void redraw(Uint32 *dst) { | |
clear(dst); | |
drawbody(dst); | |
SDL_UpdateTexture(gTexture, NULL, dst, WIDTH * sizeof(Uint32)); | |
SDL_RenderClear(gRenderer); | |
SDL_RenderCopy(gRenderer, gTexture, NULL, NULL); | |
SDL_RenderPresent(gRenderer); | |
} | |
void dotext(SDL_Event *event) { | |
int i; | |
for(i = 0; i < SDL_TEXTINPUTEVENT_TEXT_SIZE; ++i) { | |
char c = event->text.text[i]; | |
if(c < ' ' || c > '~') break; | |
pushchar(c); | |
} | |
redraw(pixels); | |
} | |
void dokey(SDL_Event *event) { | |
switch(event->key.keysym.sym) { | |
case SDLK_RETURN: pushchar('\n'); break; | |
case SDLK_DOWN: down(); break; | |
case SDLK_UP: up(); break; | |
case SDLK_LEFT: left(); break; | |
case SDLK_RIGHT: right(); break; | |
} | |
} | |
int loadchr(FILE *f) { | |
if(!f) return error("Load", "Invalid font file"); | |
if(!fread(chrbuf, sizeof(chrbuf), 1, f)) | |
return error("Load", "Invalid font file size"); | |
puts("Load: Complete"); | |
fclose(f); | |
return 1; | |
} | |
int init(void) { | |
if(SDL_Init(SDL_INIT_VIDEO) < 0) | |
return error("Init", SDL_GetError()); | |
gWindow = SDL_CreateWindow("Moogle", | |
SDL_WINDOWPOS_UNDEFINED, | |
SDL_WINDOWPOS_UNDEFINED, | |
WIDTH * ZOOM, | |
HEIGHT * ZOOM, | |
SDL_WINDOW_SHOWN); | |
if(gWindow == NULL) | |
return error("Window", SDL_GetError()); | |
gRenderer = SDL_CreateRenderer(gWindow, -1, 0); | |
if(gRenderer == NULL) | |
return error("Renderer", SDL_GetError()); | |
gTexture = SDL_CreateTexture(gRenderer, | |
SDL_PIXELFORMAT_ARGB8888, | |
SDL_TEXTUREACCESS_STATIC, | |
WIDTH, | |
HEIGHT); | |
if(gTexture == NULL) | |
return error("Texture", SDL_GetError()); | |
pixels = (Uint32 *)malloc(WIDTH * HEIGHT * sizeof(Uint32)); | |
if(pixels == NULL) | |
return error("Pixels", "Failed to allocate memory"); | |
clear(pixels); | |
return 1; | |
} | |
void quit(void) { | |
free(pixels); | |
SDL_DestroyTexture(gTexture); | |
gTexture = NULL; | |
SDL_DestroyRenderer(gRenderer); | |
gRenderer = NULL; | |
SDL_DestroyWindow(gWindow); | |
gWindow = NULL; | |
SDL_Quit(); | |
exit(0); | |
} | |
int main(int argc, char *argv[]) { | |
int ticknext = 0; | |
if(!init()) | |
return error("Init", "Failure"); | |
loadchr(fopen("type.chr", "r")); | |
if(argc > 1) | |
loadtxt(argv[1]); | |
redraw(pixels); | |
while(1) { | |
int tick = SDL_GetTicks(); | |
SDL_Event event; | |
if(tick < ticknext) | |
SDL_Delay(ticknext - tick); | |
ticknext = tick + (1000 / FPS); | |
while(SDL_PollEvent(&event) != 0) { | |
switch(event.type) { | |
case SDL_QUIT: quit(); break; | |
case SDL_TEXTINPUT: dotext(&event); break; | |
case SDL_KEYDOWN: dokey(&event); break; | |
} | |
} | |
} | |
quit(); | |
return 0; | |
} |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
#include <SDL2/SDL.h> | |
#include <stdio.h> | |
int error(char *msg, const char *err) { | |
printf("Error %s: %s\n", msg, err); | |
return 0; | |
} | |
#define HOR 32 | |
#define VER 16 | |
#define PAD 8 | |
#define TEXTSZ 1024 * 32 | |
char text_before[TEXTSZ+1]; /* index 0 = start of file */ | |
int text_before_len = 0; /* where the next char typed will go */ | |
char text_after[TEXTSZ+1]; /* index 0 = end of file */ | |
int text_after_len = 0; | |
void pushchar(char c) { | |
if(text_before_len + text_after_len >= TEXTSZ) | |
return; | |
text_before[text_before_len++] = c; | |
} | |
void left() { | |
if(text_before_len == 0) return; | |
text_after[text_after_len] = text_before[text_before_len-1]; | |
++text_after_len; | |
--text_before_len; | |
text_before[text_before_len] = '\0'; | |
} | |
void right() { | |
if(text_after_len == 0) return; | |
text_before[text_before_len] = text_after[text_after_len-1]; | |
++text_before_len; | |
--text_after_len; | |
text_before[text_after_len] = '\0'; | |
} | |
int loadtxt(char *name) { | |
char line[256]; | |
FILE *f = fopen(name, "r"); | |
if(!f) return error("Load", "Invalid input file"); | |
text_before_len = 0; | |
text_after_len = 0; | |
while(fgets(line, 256, f)) { | |
int i = 0; | |
char c; | |
while((c = line[i++])) | |
pushchar(c); | |
} | |
/* reset cursor */ | |
while(text_before_len > 0) | |
left(); | |
printf("Loaded: %s\n", name); | |
fclose(f); | |
return 1; | |
} | |
int cursorcol() { | |
int result = 0; | |
int c; | |
for(c = text_before_len-1; c >= 0; --c) { | |
if(text_before[c] == '\n') break; | |
++result; | |
} | |
return result; | |
} | |
void down() { | |
int col = cursorcol(); | |
/* skip rest of line */ | |
while(text_after_len > 0 && text_after[text_after_len-1] != '\n') | |
right(); | |
/* scan forward on next line */ | |
right(); | |
for(; col > 0 && text_after_len > 0 && text_after[text_after_len-1] != '\n'; --col) | |
right(); | |
} | |
void up() { | |
int col = cursorcol(); | |
/* scan back to end of previous line */ | |
left(); | |
while(text_before_len > 0 && text_before[text_before_len-1] != '\n') | |
left(); | |
/* scan back to start of previous line */ | |
left(); | |
while(text_before_len > 0 && text_before[text_before_len-1] != '\n') | |
left(); | |
/* scan forward on previous line */ | |
for(; col > 0 && text_after_len > 0 && text_after[text_after_len-1] != '\n'; --col) | |
right(); | |
} | |
int WIDTH = 8 * HOR + PAD * 2; | |
int HEIGHT = 8 * (VER + 2) + PAD * 2; | |
int FPS = 30, GUIDES = 1, ZOOM = 2; | |
Uint8 chrbuf[2048]; | |
SDL_Window *gWindow = NULL; | |
SDL_Renderer *gRenderer = NULL; | |
SDL_Texture *gTexture = NULL; | |
Uint32 *pixels; | |
void clear(Uint32 *dst) { | |
int i, j; | |
for(i = 0; i < HEIGHT; i++) | |
for(j = 0; j < WIDTH; j++) | |
dst[i * WIDTH + j] = 0; | |
} | |
void putpixel(Uint32 *dst, int x, int y) { | |
if(x >= 0 && x < WIDTH - 8 && y >= 0 && y < HEIGHT - 8) | |
dst[(y + PAD) * WIDTH + (x + PAD)] = 0xffffffff; | |
} | |
void drawletter(Uint32 *dst, int x, int y, int id) { | |
int v, h, offset = id * 16; | |
for(v = 0; v < 8; v++) | |
for(h = 0; h < 8; h++) { | |
int px = (x * 8) + (8 - h); | |
int py = (y * 8) + v; | |
int ch1 = chrbuf[offset + v]; | |
int ch2 = chrbuf[offset + v + 8]; | |
int clr = ((ch1 >> h) & 0x1) + (((ch2 >> h) & 0x1) << 1); | |
if(clr) | |
putpixel(dst, px, py); | |
} | |
} | |
void drawbody(Uint32 *dst) { | |
int i, x = 0, line = 0; | |
for(i = 0; i < text_before_len; ++i) { | |
char c = text_before[i]; | |
drawletter(dst, x, line, (int)c); | |
x++; | |
if(c == '\n') { | |
x = 0; | |
line++; | |
} | |
} | |
for(i = text_after_len-1; i >= 0; --i) { | |
char c = text_after[i]; | |
drawletter(dst, x, line, (int)c); | |
x++; | |
if(c == '\n') { | |
x = 0; | |
line++; | |
} | |
} | |
} | |
void redraw(Uint32 *dst) { | |
clear(dst); | |
drawbody(dst); | |
SDL_UpdateTexture(gTexture, NULL, dst, WIDTH * sizeof(Uint32)); | |
SDL_RenderClear(gRenderer); | |
SDL_RenderCopy(gRenderer, gTexture, NULL, NULL); | |
SDL_RenderPresent(gRenderer); | |
} | |
void dotext(SDL_Event *event) { | |
int i; | |
for(i = 0; i < SDL_TEXTINPUTEVENT_TEXT_SIZE; ++i) { | |
char c = event->text.text[i]; | |
if(c < ' ' || c > '~') break; | |
pushchar(c); | |
} | |
redraw(pixels); | |
} | |
void dokey(SDL_Event *event) { | |
switch(event->key.keysym.sym) { | |
case SDLK_RETURN: pushchar('\n'); break; | |
case SDLK_DOWN: down(); break; | |
case SDLK_UP: up(); break; | |
case SDLK_LEFT: left(); break; | |
case SDLK_RIGHT: right(); break; | |
} | |
} | |
int loadchr(FILE *f) { | |
if(!f) return error("Load", "Invalid font file"); | |
if(!fread(chrbuf, sizeof(chrbuf), 1, f)) | |
return error("Load", "Invalid font file size"); | |
puts("Load: Complete"); | |
fclose(f); | |
return 1; | |
} | |
int init(void) { | |
if(SDL_Init(SDL_INIT_VIDEO) < 0) | |
return error("Init", SDL_GetError()); | |
gWindow = SDL_CreateWindow("Moogle", | |
SDL_WINDOWPOS_UNDEFINED, | |
SDL_WINDOWPOS_UNDEFINED, | |
WIDTH * ZOOM, | |
HEIGHT * ZOOM, | |
SDL_WINDOW_SHOWN); | |
if(gWindow == NULL) | |
return error("Window", SDL_GetError()); | |
gRenderer = SDL_CreateRenderer(gWindow, -1, 0); | |
if(gRenderer == NULL) | |
return error("Renderer", SDL_GetError()); | |
gTexture = SDL_CreateTexture(gRenderer, | |
SDL_PIXELFORMAT_ARGB8888, | |
SDL_TEXTUREACCESS_STATIC, | |
WIDTH, | |
HEIGHT); | |
if(gTexture == NULL) | |
return error("Texture", SDL_GetError()); | |
pixels = (Uint32 *)malloc(WIDTH * HEIGHT * sizeof(Uint32)); | |
if(pixels == NULL) | |
return error("Pixels", "Failed to allocate memory"); | |
clear(pixels); | |
return 1; | |
} | |
void quit(void) { | |
free(pixels); | |
SDL_DestroyTexture(gTexture); | |
gTexture = NULL; | |
SDL_DestroyRenderer(gRenderer); | |
gRenderer = NULL; | |
SDL_DestroyWindow(gWindow); | |
gWindow = NULL; | |
SDL_Quit(); | |
exit(0); | |
} | |
int main(int argc, char *argv[]) { | |
int ticknext = 0; | |
if(!init()) | |
return error("Init", "Failure"); | |
loadchr(fopen("type.chr", "r")); | |
if(argc > 1) | |
loadtxt(argv[1]); | |
redraw(pixels); | |
while(1) { | |
int tick = SDL_GetTicks(); | |
SDL_Event event; | |
if(tick < ticknext) | |
SDL_Delay(ticknext - tick); | |
ticknext = tick + (1000 / FPS); | |
while(SDL_PollEvent(&event) != 0) { | |
switch(event.type) { | |
case SDL_QUIT: quit(); break; | |
case SDL_TEXTINPUT: dotext(&event); break; | |
case SDL_KEYDOWN: dokey(&event); break; | |
} | |
} | |
} | |
quit(); | |
return 0; | |
} |
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