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Diffstat (limited to 'src/libjin/Render/Font.cpp')
| -rw-r--r-- | src/libjin/Render/Font.cpp | 193 |
1 files changed, 193 insertions, 0 deletions
diff --git a/src/libjin/Render/Font.cpp b/src/libjin/Render/Font.cpp new file mode 100644 index 0000000..e8e71b2 --- /dev/null +++ b/src/libjin/Render/Font.cpp @@ -0,0 +1,193 @@ +#include "../modules.h" +#if JIN_MODULES_RENDER + +#include "font.h" +#include <stdio.h> +#define STB_TRUETYPE_IMPLEMENTATION +#include "3rdparty/stb/stb_truetype.h" +#include "color.h" + +namespace jin +{ +namespace render +{ + + using namespace jin::math; + +#define BITMAP_WIDTH 512 +#define BITMAP_HEIGHT 512 +#define PIXEL_HEIGHT 32 + + Font::Font():Drawable() + { + } + + // ttf file read buffer + static unsigned char ttf_buffer[1 << 20]; + + // bitmap for saving font data + static unsigned char temp_bitmap[BITMAP_WIDTH * BITMAP_HEIGHT]; + + void Font::loadf(const char* path) + { + fread(ttf_buffer, 1, 1 << 20, fopen(path, "rb")); + + loadb(ttf_buffer); + } + + /** + * load from memory + */ + void Font::loadb(const unsigned char* data) + { + stbtt_BakeFontBitmap(data, 0, PIXEL_HEIGHT, temp_bitmap, BITMAP_WIDTH, BITMAP_HEIGHT, 32, 96, cdata); + + glGenTextures(1, &texture); + glBindTexture(GL_TEXTURE_2D, texture); + + glTexImage2D(GL_TEXTURE_2D, 0, GL_ALPHA, BITMAP_WIDTH, + BITMAP_HEIGHT, 0, GL_ALPHA, GL_UNSIGNED_BYTE, temp_bitmap); + + glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST); + glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST); + + glBindTexture(GL_TEXTURE_2D, 0); + } + + /** + * get texture quad + */ + static Quad getCharQuad(const stbtt_bakedchar* chardata, int pw, int ph, int char_index) + { + float ipw = 1.0f / pw, iph = 1.0f / ph; + const stbtt_bakedchar *b = chardata + char_index; + Quad q; + q.x = b->x0 * ipw; + q.y = b->y0 * iph; + q.w = b->x1 * ipw - b->x0 * ipw; + q.h = b->y1 * iph - b->y0 * iph; + return q; + } + + /** + * render function draw mutiple times + * in loop + */ + void Font::render( + const char* text, // rendered text + float x, float y, // render position + int fheight, // font height + int spacing, // font spacing + int lheight) // line height + { + float _x = x, + _y = y; + + int len = strlen(text); + + glEnable(GL_TEXTURE_2D); + glBindTexture(GL_TEXTURE_2D, texture); + + glEnableClientState(GL_VERTEX_ARRAY); + glEnableClientState(GL_TEXTURE_COORD_ARRAY); + + // for saving clip quad + stbtt_aligned_quad q; + + // render every given character + int xc = x; + int yc = y; + + float factor = fheight / (float)PIXEL_HEIGHT; + + for (int i = 0; i < len; ++i) + { + char c = text[i]; + if (c == '\n') + { + xc = x; + yc += lheight; + continue; + } + + // only support ASCII + Quad q = getCharQuad(cdata, 512, 512, c - 32); + float s0 = q.x, + s1 = q.x + q.w, + t0 = q.y, + t1 = q.y + q.h; + + // texture quad + float tc[] = { + s0, t1, + s1, t1, + s1, t0, + s0, t0 + }; + + // character bound box + stbtt_bakedchar box = cdata[c - 32]; + + float width = factor * (box.x1 - box.x0); + float height = factor * (box.y1 - box.y0); + float xoffset = factor * box.xoff; + // I don't know why add PIXEL_HEIGHT to box.yoff, but + // it works. + float yoffset = factor * (box.yoff + PIXEL_HEIGHT); + float xadvance = factor * box.xadvance; + + // render quad + float vc[] = { + xc + xoffset, yc + height + yoffset, + xc + width + xoffset, yc + height + yoffset, + xc + width + xoffset, yc + yoffset, + xc + xoffset, yc + yoffset + }; + + // forward to next character + xc += xadvance + spacing; + + glTexCoordPointer(2, GL_FLOAT, 0, tc); + glVertexPointer(2, GL_FLOAT, 0, vc); + glDrawArrays(GL_QUADS, 0, 4); + } + + glDisableClientState(GL_TEXTURE_COORD_ARRAY); + glDisableClientState(GL_VERTEX_ARRAY); + + glBindTexture(GL_TEXTURE_2D, 0); + glDisable(GL_TEXTURE_2D); + } + + void Font::box(const char* str, int fheight, int spacing, int lheight, int* w, int * h) + { + int len = strlen(str); + + float xc = 0; + int yc = len ? lheight: 0; + int maxX = 0; + + float factor = fheight / (float)PIXEL_HEIGHT; + + for (int i = 0; i < len; ++i) + { + char c = str[i]; + if (c == '\n') + { + yc += lheight; + xc = 0; + continue; + } + stbtt_bakedchar box = cdata[c - 32]; + + xc += factor * box.xadvance + spacing; + if (xc > maxX) maxX = xc; + } + + *w = maxX; + *h = yc; + } + +} +} +#endif // JIN_MODULES_RENDER
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