Dawn/src/display/font.h

139 lines
4.0 KiB
C

/**
* Copyright (c) 2021 Dominic Masters
*
* This software is released under the MIT License.
* https://opensource.org/licenses/MIT
*/
#pragma once
#include "../libs.h"
#include "texture.h"
#include "primitive/primitive.h"
#include "primitive/quad.h"
#include "../util/mem.h"
#include "../util/math.h"
#include "../assert/assert.h"
/** Which character (ASCII) to start the font from */
#define FONT_FIRST_CHAR 32
/** How many characters (after the first char) to generate */
#define FONT_NUM_CHARS 96
/** Width of the loaded font texture */
#define FONT_TEXTURE_WIDTH 1024
/** Height of the loaded font texture */
#define FONT_TEXTURE_HEIGHT FONT_TEXTURE_WIDTH
/** Refer to STBTT docs for OpenGL Fill Mode v d3d Fill Modes */
#define FONT_FILL_MODE 1
/** Passed to STBTT for scaling the font, essentially the font resolution */
#define FONT_TEXTURE_SIZE 64.0f
/** The global scale, just used to provide fine control of font sizes */
#define FONT_GLOBAL_SCALE 0.5f;
/** Default Font Size (on which all font scales are based) */
#define FONT_SIZE_DEFAULT 16.0f
// Chars
#define FONT_NEWLINE '\n'
#define FONT_SPACE ' '
// Heights
#define FONT_LINE_HEIGHT FONT_TEXTURE_SIZE * 0.75f
#define FONT_INITIAL_LINE FONT_LINE_HEIGHT * 0.75f
#define FONT_SPACE_SIZE FONT_TEXTURE_SIZE * 0.45f
/** Maximum number of newlines that a font text info can hold. */
#define FONT_TEXT_INFO_LINES_MAX 16
/** Representation of a font that can be used to render text */
typedef struct {
texture_t texture;
stbtt_bakedchar characterData[FONT_NUM_CHARS];
} font_t;
typedef struct {
/** What (real character) index the line starts at */
int32_t start;
/** How many (real) characters the line is in length */
int32_t length;
} fonttextinfoline_t;
typedef struct {
/** How many raw chars are in the string */
int32_t length;
/** How many real characters (non whitespace) are in the string */
int32_t realLength;
/** How many lines is the string? Trailing newlines will count */
int32_t lineCount;
/** The real character info for each line */
fonttextinfoline_t lines[FONT_TEXT_INFO_LINES_MAX];
/** Dimensions of the string */
float width, height;
} fonttextinfo_t;
/**
* Initializes Font from raw TTF data.
* @param font Font to initialize
* @param data Data to intialize for.
*/
void fontInit(font_t *font, char *data);
/**
* Clean up a previously loaded font
* @param font Loaded font.
*/
void fontDispose(font_t *Font);
/**
* Convert a Font's Size into a Font Scale. The scale is based on the font's
* default size for the given texture size (Refer to FONT_SIZE_DEFAULT).
*
* @param fontSize Font size to convert.
* @return The times scale that the font size is to the textured default.
*/
float fontGetScale(float fontSize);
/**
* Internal method that adds a line to the text buffer process.
*
* @param info Info to add to.
* @param start Start character index for the next line.
* @param len Length of the next line.
* @return True if added a line successfully, otherwise false.
*/
bool _fontTextBufferAddLine(fonttextinfo_t *info, int32_t start, int32_t len);
/**
* Clamps text to a max width, inserting newlines where possible.
*
* @param font Font to use
* @param primitive Primitive to buffer the text to.
* @param info Font text info to clamp into.
* @param text Text to clamp.
* @param maxWidth Max width (pixels) to clamp the text to, -1 for no max width.
* @param fontSize Font Size of the text.
*/
void fontTextBuffer(
font_t *font, primitive_t *primitive, fonttextinfo_t *info, char *text,
float maxWidth, float fontSize
);
/**
* Returns the number of real characters on the lines specified. Useful when
* attempting to clamp to a set of lines.
*
* @param info Info to get the character counts from.
* @param start Starting line index.
* @param count Count of lines, this method will clamp to info's line length.
* @returns The count of characters in those lines summed.
*/
int32_t fontGetLineCharCount(fonttextinfo_t *info, int32_t start,int32_t count);