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Packed font rendering

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This commit is contained in:
John Alanbrook
2022-12-28 22:50:54 +00:00
parent 329e10f2d6
commit 76273e1c54
23 changed files with 211 additions and 132 deletions
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126
source/engine/font.c
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@@ -13,6 +13,7 @@
#include "openglrender.h"
#include <stb_truetype.h>
#include "stb_rect_pack.h"
static uint32_t VBO = 0;
static uint32_t VAO = 0;
@@ -50,7 +51,6 @@ void font_frame(struct window *w) {
shader_use(shader);
}
// Height in pixels
struct sFont *MakeFont(const char *fontfile, int height)
{
shader_use(shader);
@@ -62,6 +62,18 @@ struct sFont *MakeFont(const char *fontfile, int height)
snprintf(fontpath, 256, "fonts/%s", fontfile);
fread(ttf_buffer, 1, 1<<25, fopen(fontpath, "rb"));
unsigned char *bitmap = malloc(1024*1024);
stbtt_packedchar glyphs[95];
stbtt_pack_context pc;
stbtt_PackBegin(&pc, bitmap, 1024, 1024, 0, 1, NULL);
stbtt_PackSetOversampling(&pc, 1, 1);
stbtt_PackFontRange(&pc, ttf_buffer, 0, height, 32, 95, glyphs);
stbtt_PackEnd(&pc);
stbtt_fontinfo fontinfo;
if (!stbtt_InitFont(&fontinfo, ttf_buffer, stbtt_GetFontOffsetForIndex(ttf_buffer,0))) {
@@ -69,47 +81,45 @@ struct sFont *MakeFont(const char *fontfile, int height)
}
float scale = stbtt_ScaleForPixelHeight(&fontinfo, height);
//glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
glGenTextures(1, &newfont->texID);
glBindTexture(GL_TEXTURE_2D, newfont->texID);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RED, 1024, 1024, 0, GL_RED, GL_UNSIGNED_BYTE, bitmap);
glGenerateMipmap(GL_TEXTURE_2D);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
int ascent, descent, linegap;
stbtt_GetFontVMetrics(&fontinfo, &ascent, &descent, &linegap);
ascent = roundf(ascent*scale);
descent = roundf(descent*scale);
glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
for (unsigned char c = 32; c < 127; c++) {
unsigned char *bitmap;
//unsigned char *bitmap;
int advance, lsb, w, h, x0, y0;
stbtt_GetCodepointHMetrics(&fontinfo, c, &advance, &lsb);
stbtt_packedchar glyph = glyphs[c-32];
bitmap = stbtt_GetCodepointBitmap(&fontinfo, scale, scale, c, &w, &h, &x0, &y0);
YughInfo("Packed char is at %d, %d, %d, %d", glyphs[c-32].x0, glyphs[c-32].y0, glyphs[c-32].x1, glyphs[c-32].y1);
GLuint ftexture;
glGenTextures(1, &ftexture);
glBindTexture(GL_TEXTURE_2D, ftexture);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RED, w, h, 0, GL_RED, GL_UNSIGNED_BYTE, bitmap);
glGenerateMipmap(GL_TEXTURE_2D);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
newfont->Characters[c].TextureID = ftexture;
struct glrect r;
r.s0 = glyph.x0 / (float)1024;
r.s1 = glyph.x1 / (float) 1024;
r.t0 = glyph.y0 / (float) 1024;
r.t1 = glyph.y1 / (float) 1024;
YughInfo("That is %f %f %f %f", r.s0, r.t0, r.s1, r.t1);
newfont->Characters[c].Advance = advance * scale;
newfont->Characters[c].Size[0] = w;
newfont->Characters[c].Size[1] = h;
newfont->Characters[c].Size[0] = glyphs[c-32].x1 - glyphs[c-32].x0;
newfont->Characters[c].Size[1] = glyphs[c-32].y1 - glyphs[c-32].y0;
newfont->Characters[c].Bearing[0] = x0;
newfont->Characters[c].Bearing[1] = y0*-1;
newfont->Characters[c].rect = r;
}
return newfont;
}
static int curchar = 0;
void sdrawCharacter(struct Character c, mfloat_t cursor[2], float scale, struct shader *shader, float color[3])
{
float w = c.Size[0] * scale;
@@ -119,58 +129,15 @@ void sdrawCharacter(struct Character c, mfloat_t cursor[2], float scale, struct
float ypos = cursor[1] + (c.Bearing[1] * scale) - h;
float verts[4 * 4] = {
xpos, ypos, 0.f, 0.f,
xpos+w, ypos, 1.f, 0.f,
xpos, ypos + h, 0.f, 1.f,
xpos + w, ypos + h, 1.f, 1.f
xpos, ypos, c.rect.s0, c.rect.t1,
xpos+w, ypos, c.rect.s1, c.rect.t1,
xpos, ypos + h, c.rect.s0, c.rect.t0,
xpos + w, ypos + h, c.rect.s1, c.rect.t0
};
glBindTexture(GL_TEXTURE_2D, c.TextureID);
glBufferSubData(GL_ARRAY_BUFFER, 0, sizeof(verts), verts);
glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
glBufferSubData(GL_ARRAY_BUFFER, curchar*sizeof(verts), sizeof(verts), verts);
////// Outline calculation
// float outlineWidth = 1.1;
// float ow = c.Size[0] * scale * outlineWidth;
// float oh = c.Size[1] * scale * outlineWidth;
// float oxpos = cursor[0] + c.Bearing[0] * scale * outlineWidth - ((ow-w)/2);
// float oypos = cursor[1] - (c.Size[1] - c.Bearing[1]) * scale * outlineWidth - ((oh-h)/2);
// float overts[4*4] = {
// oxpos, oypos + oh, 0.f, 0.f,
// oxpos, oypos, 0.f, 1.f,
// oxpos + ow, oypos + oh, 1.f, 0.f,
// oxpos + ow, oypos, 1.f, 1.f
// };
/////////// Shadow calculation
/*
float shadowOffset = 6.f;
float sxpos = cursor[0] + c.Bearing[0] * scale + (scale * shadowOffset);
float sypos = cursor[1] - (c.Size[1] - c.Bearing[1]) * scale - (scale * shadowOffset);
float sverts[4 * 4] = {
sxpos, sypos, 0.f, 0.f,
sxpos+w, sypos, 1.f, 0.f,
sxpos, sypos + h, 0.f, 1.f,
sxpos + w, sypos+h, 1.f, 1.f
};
//// Shadow pass
float black[3] = { 0, 0, 0 };
shader_setvec3(shader, "textColor", black);
glBufferSubData(GL_ARRAY_BUFFER, 0, sizeof(sverts), sverts);
glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
*/
curchar++;
}
void text_settype(struct sFont *mfont)
@@ -183,17 +150,24 @@ void renderText(const char *text, mfloat_t pos[2], float scale, mfloat_t color[3
shader_use(shader);
shader_setvec3(shader, "textColor", color);
int len = strlen(text);
mfloat_t cursor[2] = { 0.f };
cursor[0] = pos[0];
cursor[1] = pos[1];
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, font->texID);
glBindVertexArray(VAO);
glBindBuffer(GL_ARRAY_BUFFER, VBO);
glBufferData(GL_ARRAY_BUFFER, len*16*sizeof(float), NULL, GL_STREAM_DRAW);
const unsigned char *line, *wordstart;
line = (unsigned char*)text;
curchar = 0;
while (*line != '\0') {
@@ -230,4 +204,6 @@ void renderText(const char *text, mfloat_t pos[2], float scale, mfloat_t color[3
}
}
}
glDrawArrays(GL_TRIANGLE_STRIP, 0, 4*curchar);
}