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#include "hitomezashi.h"
#include "SDL.h"
#include <assert.h>
SDL_Color HITOMEZASHI_FG_COLOUR = {.r = 0, .g = 0, .b = 0};
SDL_Color HITOMEZASHI_BG_COLOUR = {.r = 255, .g = 255, .b = 255};
enum Hitomezashi_State_Init_Result
hitomezashi_state_init(struct Hitomezashi_State *state, int x_pattern_len,
int y_pattern_len, char *x_pattern, char *y_pattern,
int gap, int line_thickness) {
assert(x_pattern_len >= 0);
assert(y_pattern_len >= 0);
assert(gap >= 0);
assert(line_thickness > 0);
state->y_pattern_len = y_pattern_len;
state->x_pattern_len = x_pattern_len;
state->x_pattern = x_pattern;
state->y_pattern = y_pattern;
state->gap = gap;
state->line_thickness = line_thickness;
state->output_width = x_pattern_len * gap;
state->output_height = y_pattern_len * gap;
state->surface = SDL_CreateRGBSurface(0, state->output_width,
state->output_height, 32, 0, 0, 0, 0);
if (!state->surface) {
return Hitomezashi_State_Init_Result_Err_Create_Surface;
}
return Hitomezashi_State_Init_Result_Success;
}
enum Hitomezashi_Draw_Result hitomezashi_draw(struct Hitomezashi_State *state) {
if (SDL_LockSurface(state->surface) != 0) {
return Hitomezashi_Draw_Result_Err_Lock_Surface;
}
Uint32 bg_colour =
SDL_MapRGB(state->surface->format, HITOMEZASHI_BG_COLOUR.r,
HITOMEZASHI_BG_COLOUR.g, HITOMEZASHI_BG_COLOUR.b);
Uint32 fg_colour =
SDL_MapRGB(state->surface->format, HITOMEZASHI_FG_COLOUR.r,
HITOMEZASHI_FG_COLOUR.g, HITOMEZASHI_FG_COLOUR.b);
SDL_FillRect(state->surface, NULL, bg_colour);
SDL_Rect rect;
// Draw y pattern (horizontal) lines
for (int i = 0; i < state->y_pattern_len; ++i) {
for (int j = 0; j < state->x_pattern_len; ++j) {
if (j % 2 == state->y_pattern[i]) {
rect.x = j * state->gap;
rect.y = i * state->gap;
rect.w = state->gap;
rect.h = state->line_thickness;
SDL_FillRect(state->surface, &rect, fg_colour);
}
}
}
// Draw x pattern (vertical) lines
for (int i = 0; i < state->x_pattern_len; ++i) {
for (int j = 0; j < state->y_pattern_len; ++j) {
if (j % 2 == state->x_pattern[i]) {
rect.x = i * state->gap;
rect.y = j * state->gap;
rect.w = state->line_thickness;
rect.h = state->gap;
SDL_FillRect(state->surface, &rect, fg_colour);
}
}
}
// Join up the lines to avoid leaving holes at the intersections
// To understand how this works, try commenting it out and see the output
for (int x = state->gap; x < state->output_width; x += state->gap) {
for (int y = state->gap; y < state->output_height; y += state->gap) {
rect.x = x;
rect.y = y;
rect.w = state->line_thickness;
rect.h = state->line_thickness;
SDL_FillRect(state->surface, &rect, fg_colour);
}
}
SDL_UnlockSurface(state->surface);
return Hitomezashi_Draw_Result_Success;
}
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