keyboard.c File Reference

#include "SDL.h"
#include "common.h"

Include dependency graph for keyboard.c:

Go to the source code of this file.

Data Structures
struct	fontMapping

Macros
#define	TEST_INPUT_RECT
#define	GLYPH_SIZE_IMAGE   16 /* size of glyphs (characters) in the bitmap font file */
#define	GLYPH_SIZE_SCREEN   32 /* size of glyphs (characters) as shown on the screen */
#define	MAX_CHARS   1024
#define	TABLE_SIZE   51 /* size of our table which maps keys and modifiers to font indices */

Functions
int	keyToGlyphIndex (SDL_Keysym key)
void	getPositionForCharNumber (int n, int *x, int *y)
void	drawGlyph (int glyph, int positionIndex)
SDL_Texture *	loadFont (void)
void	draw ()
int	main (int argc, char *argv[])

Variables
static SDL_Texture *	texture
static SDL_Renderer *	renderer
static int	numChars = 0
static SDL_Color	bg_color = { 50, 50, 100, 255 }
static int	glyphs [MAX_CHARS]
fontMapping	map [TABLE_SIZE]

Macro Definition Documentation

GLYPH_SIZE_IMAGE

#define GLYPH_SIZE_IMAGE   16 /* size of glyphs (characters) in the bitmap font file */

Definition at line 12 of file keyboard.c.

Referenced by drawGlyph(), and main().

GLYPH_SIZE_SCREEN

#define GLYPH_SIZE_SCREEN   32 /* size of glyphs (characters) as shown on the screen */

Definition at line 13 of file keyboard.c.

Referenced by drawGlyph(), and getPositionForCharNumber().

MAX_CHARS

#define MAX_CHARS   1024

Definition at line 15 of file keyboard.c.

Referenced by main().

TABLE_SIZE

#define TABLE_SIZE   51 /* size of our table which maps keys and modifiers to font indices */

Definition at line 38 of file keyboard.c.

Referenced by keyToGlyphIndex().

TEST_INPUT_RECT

#define TEST_INPUT_RECT

Definition at line 10 of file keyboard.c.

Function Documentation

draw()

void draw

(

)

Definition at line 199 of file keyboard.c.

References SDL_Color::a, SDL_Color::b, drawGlyph(), SDL_Color::g, glyphs, i, numChars, SDL_Color::r, SDL_RenderClear, SDL_RenderPresent, and SDL_SetRenderDrawColor.

Referenced by main().

{
    SDL_SetRenderDrawColor(renderer, bg_color.r, bg_color.g, bg_color.b, bg_color.a);
    SDL_RenderClear(renderer);

    for (int i = 0; i < numChars; i++) {
        drawGlyph(glyphs[i], i);
    }

    drawGlyph(29, numChars); /* cursor is at index 29 in the bitmap font */

    SDL_RenderPresent(renderer);
}

drawGlyph()

void drawGlyph	(	int	glyph,
		int	positionIndex
	)

Definition at line 153 of file keyboard.c.

References getPositionForCharNumber(), GLYPH_SIZE_IMAGE, GLYPH_SIZE_SCREEN, and SDL_RenderCopy.

Referenced by draw().

{
    int x, y;
    getPositionForCharNumber(positionIndex, &x, &y);
    SDL_Rect srcRect = { GLYPH_SIZE_IMAGE * glyph, 0, GLYPH_SIZE_IMAGE, GLYPH_SIZE_IMAGE };
    SDL_Rect dstRect = { x, y, GLYPH_SIZE_SCREEN, GLYPH_SIZE_SCREEN };
    SDL_RenderCopy(renderer, texture, &srcRect, &dstRect);
}

getPositionForCharNumber()

void getPositionForCharNumber	(	int	n,
		int *	x,
		int *	y
	)

Definition at line 134 of file keyboard.c.

References GLYPH_SIZE_SCREEN, and SDL_RenderGetLogicalSize.

Referenced by drawGlyph().

{
    int renderW, renderH;
    SDL_RenderGetLogicalSize(renderer, &renderW, &renderH);

    int x_padding = 16;         /* padding space on left and right side of screen */
    int y_padding = 32;         /* padding space at top of screen */
    /* figure out the number of characters that can fit horizontally across the screen */
    int max_x_chars = (renderW - 2 * x_padding) / GLYPH_SIZE_SCREEN;
    int line_separation = 5;    /* pixels between each line */
    *x = (n % max_x_chars) * GLYPH_SIZE_SCREEN + x_padding;
#ifdef TEST_INPUT_RECT
    *y = renderH - GLYPH_SIZE_SCREEN;
#else
    *y = (n / max_x_chars) * (GLYPH_SIZE_SCREEN + line_separation) + y_padding;
#endif
}

keyToGlyphIndex()

int keyToGlyphIndex

(

SDL_Keysym

key

)

Definition at line 111 of file keyboard.c.

References fontMapping::allow_no_mod, i, fontMapping::index, fontMapping::mod, SDL_Keysym::mod, fontMapping::scancode, SDL_Keysym::scancode, and TABLE_SIZE.

Referenced by main().

{
    int i, index = -1;
    for (i = 0; i < TABLE_SIZE; i++) {
        fontMapping compare = map[i];
        if (key.scancode == compare.scancode) {
            /* if this entry is valid with no key mod and we have no keymod, or if
               the key's modifiers are allowed modifiers for that mapping */
            if ((compare.allow_no_mod && key.mod == 0)
                || (key.mod & compare.mod)) {
                index = compare.index;
                break;
            }
        }
    }
    return index;
}

loadFont()

SDL_Texture* loadFont

(

void

)

Definition at line 164 of file keyboard.c.

References SDL_Surface::format, SDL_Surface::h, NULL, SDL_BLENDMODE_BLEND, SDL_BlitSurface, SDL_CreateRGBSurface, SDL_CreateTextureFromSurface, SDL_FreeSurface, SDL_GetError, SDL_LoadBMP, SDL_MapRGB, SDL_PIXELFORMAT_ABGR8888, SDL_PixelFormatEnumToMasks, SDL_SetColorKey, SDL_SetTextureBlendMode, texture, and SDL_Surface::w.

Referenced by main().

{
    SDL_Surface *surface = SDL_LoadBMP("kromasky_16x16.bmp");

    if (!surface) {
        printf("Error loading bitmap: %s\n", SDL_GetError());
        return 0;
    } else {
        /* set the transparent color for the bitmap font (hot pink) */
        SDL_SetColorKey(surface, 1, SDL_MapRGB(surface->format, 238, 0, 252));
        /* now we convert the surface to our desired pixel format */
        int format = SDL_PIXELFORMAT_ABGR8888;  /* desired texture format */
        Uint32 Rmask, Gmask, Bmask, Amask;      /* masks for desired format */
        int bpp;                /* bits per pixel for desired format */
        SDL_PixelFormatEnumToMasks(format, &bpp, &Rmask, &Gmask, &Bmask,
                                   &Amask);
        SDL_Surface *converted =
            SDL_CreateRGBSurface(0, surface->w, surface->h, bpp, Rmask, Gmask,
                                 Bmask, Amask);
        SDL_BlitSurface(surface, NULL, converted, NULL);
        /* create our texture */
        texture = SDL_CreateTextureFromSurface(renderer, converted);
        if (texture == 0) {
            printf("texture creation failed: %s\n", SDL_GetError());
        } else {
            /* set blend mode for our texture */
            SDL_SetTextureBlendMode(texture, SDL_BLENDMODE_BLEND);
        }
        SDL_FreeSurface(surface);
        SDL_FreeSurface(converted);
        return texture;
    }
}

main()

int main	(	int	argc,
		char *	argv[]
	)

Definition at line 214 of file keyboard.c.

References done, draw(), SDL_WindowEvent::event, GLYPH_SIZE_IMAGE, glyphs, SDL_Rect::h, SDL_Event::key, SDL_KeyboardEvent::keysym, keyToGlyphIndex(), loadFont(), MAX_CHARS, numChars, SDL_Keysym::scancode, SDL_CreateRenderer, SDL_CreateWindow, SDL_Delay, SDL_DestroyRenderer, SDL_DestroyTexture, SDL_DestroyWindow, SDL_GetError, SDL_GetWindowSize, SDL_Init, SDL_INIT_VIDEO, SDL_IsTextInputActive, SDL_KEYDOWN, SDL_MOUSEBUTTONUP, SDL_PollEvent, SDL_Quit, SDL_QUIT, SDL_RENDERER_PRESENTVSYNC, SDL_RenderSetLogicalSize, SDL_SCANCODE_BACKSPACE, SDL_SetTextInputRect, SDL_StartTextInput, SDL_StopTextInput, SDL_WINDOW_ALLOW_HIGHDPI, SDL_WINDOW_FULLSCREEN_DESKTOP, SDL_WINDOW_RESIZABLE, SDL_WINDOWEVENT, SDL_WINDOWEVENT_RESIZED, SDL_Event::type, SDL_Rect::w, SDL_Event::window, SDL_Rect::x, and SDL_Rect::y.

{
    SDL_Window *window;
    SDL_Event event;            /* last event received */
    SDL_Scancode scancode;      /* scancode of last key we pushed */
    int width;
    int height;
    int done;
    SDL_Rect textrect;

    if (SDL_Init(SDL_INIT_VIDEO) < 0) {
        printf("Error initializing SDL: %s", SDL_GetError());
    }
    /* create window */
    window = SDL_CreateWindow("iOS keyboard test", 0, 0, 0, 0, SDL_WINDOW_FULLSCREEN_DESKTOP | SDL_WINDOW_RESIZABLE | SDL_WINDOW_ALLOW_HIGHDPI);
    /* create renderer */
    renderer = SDL_CreateRenderer(window, -1, SDL_RENDERER_PRESENTVSYNC);

    SDL_GetWindowSize(window, &width, &height);
    SDL_RenderSetLogicalSize(renderer, width, height);

    /* load up our font */
    loadFont();
    
    /* Show onscreen keyboard */
#ifdef TEST_INPUT_RECT
    textrect.x = 0;
    textrect.y = height - GLYPH_SIZE_IMAGE;
    textrect.w = width;
    textrect.h = GLYPH_SIZE_IMAGE;
    SDL_SetTextInputRect(&textrect);
#endif
    SDL_StartTextInput();

    done = 0;
    while (!done) {
        while (SDL_PollEvent(&event)) {
            switch (event.type) {
            case SDL_QUIT:
                done = 1;
                break;
            case SDL_WINDOWEVENT:
                if (event.window.event == SDL_WINDOWEVENT_RESIZED) {
                                        width = event.window.data1;
                                        height = event.window.data2;
                    SDL_RenderSetLogicalSize(renderer, width, height);
#ifdef TEST_INPUT_RECT
                    textrect.x = 0;
                    textrect.y = height - GLYPH_SIZE_IMAGE;
                    textrect.w = width;
                    textrect.h = GLYPH_SIZE_IMAGE;
                    SDL_SetTextInputRect(&textrect);
#endif
                }
                break;
            case SDL_KEYDOWN:
                if (event.key.keysym.scancode == SDL_SCANCODE_BACKSPACE) {
                    if (numChars > 0) {
                        numChars--;
                    }
                } else if (numChars + 1 < MAX_CHARS) {
                    int index = keyToGlyphIndex(event.key.keysym);
                    if (index >= 0) {
                        glyphs[numChars++] = index;
                    }
                }
                break;
            case SDL_MOUSEBUTTONUP:
                /* mouse up toggles onscreen keyboard visibility */
                if (SDL_IsTextInputActive()) {
                    SDL_StopTextInput();
                } else {
                    SDL_StartTextInput();
                }
                break;
            }
        }

        draw();
        SDL_Delay(15);
    }

    SDL_DestroyTexture(texture);
    SDL_DestroyRenderer(renderer);
    SDL_DestroyWindow(window);
    SDL_Quit();
    return 0;
}

Variable Documentation

bg_color

SDL_Color bg_color = { 50, 50, 100, 255 }

static

Definition at line 21 of file keyboard.c.

glyphs

int glyphs[MAX_CHARS]

static

Definition at line 23 of file keyboard.c.

Referenced by draw(), and main().

map

fontMapping map[TABLE_SIZE]

Definition at line 46 of file keyboard.c.

numChars

int numChars = 0

static

Definition at line 20 of file keyboard.c.

Referenced by draw(), and main().

renderer

SDL_Renderer* renderer

static

Definition at line 19 of file keyboard.c.

texture

SDL_Texture* texture

static

Definition at line 17 of file keyboard.c.

Referenced by loadFont().