stb_truetype: Fonts rendering small? #689
Description
Hi Sean!
So I'm pretty sure I'm doing something dumb I just can't see it. But my fonts are rendering smaller than they should. New Courier at 16 is barely readable, much smaller than what it should be (see comparison screenshot). I even tried this example (https://github.com/justinmeiners/stb-truetype-example/blob/master/main.c) and wrote it out to a png, still the same.
Info:
Using a slightly modified version of the rendering code in stb_truetype.
Using stb_rect_pack for the packing.
Using fixed GL on Win32.
Using VS2015 compiling for x64
Here's my rendering code:
void DrawTextAt(float X, float Y, char *Text, FDColor Color, FDFont *Font)
{
glEnable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, Font->TextureId);
glBegin(GL_QUADS);
glColor(Color);
while (*Text)
{
if (*Text >= 32 && *Text < 128)
{
stbtt_aligned_quad Quad;
stbtt_GetPackedQuad(Font->Data, Font->BitmapWidth, Font->BitmapHeight,
*Text - 32, &X, &Y, &Quad, 0);
if (*(Text+1))
{
float Scale = stbtt_ScaleForPixelHeight(&Font->Info, Font->Size);
X += Scale*stbtt_GetCodepointKernAdvance(&Font->Info, *(Text)-32, *(Text+1)-32);
}
glTexCoord2f(Quad.s0, Quad.t0); glVertex2f(Quad.x0, Quad.y0);
glTexCoord2f(Quad.s1, Quad.t0); glVertex2f(Quad.x1, Quad.y0);
glTexCoord2f(Quad.s1, Quad.t1); glVertex2f(Quad.x1, Quad.y1);
glTexCoord2f(Quad.s0, Quad.t1); glVertex2f(Quad.x0, Quad.y1);
}
++Text;
}
glEnd();
glDisable(GL_TEXTURE_2D);
}
Here's my font making code:
void MakeFontFromData(byte *FontData, float Size, FDFont *Font)
{
const int W = 1024;
const int H = 1024;
*Font = {};
Font->BitmapWidth = W;
Font->BitmapHeight = H;
Font->Bitmap = (byte *)malloc(W*H);
Font->Size = Size;
stbtt_InitFont(&Font->Info, FontData, 0);
stbtt_pack_context PackContext={};
stbtt_PackBegin(&PackContext, Font->Bitmap, W, H, 0, 1, 0);
stbtt_PackSetOversampling(&PackContext, 2, 2);
stbtt_pack_range Ranges[1]={};
Ranges[0].chardata_for_range = Font->Data;
Ranges[0].array_of_unicode_codepoints = 0;
Ranges[0].first_unicode_codepoint_in_range = 32;
Ranges[0].num_chars = 96;
Ranges[0].font_size = STBTT_POINT_SIZE(Size);
stbtt_PackFontRanges(&PackContext, FontData, 0, Ranges, 1);
stbtt_PackEnd(&PackContext);
int Ascend;
stbtt_GetFontVMetrics(&Font->Info, &Ascend, 0, 0);
float Scale = stbtt_ScaleForPixelHeight(&Font->Info, Size);
Font->Baseline = Ascend*Scale;
glGenTextures(1, &Font->TextureId);
glBindTexture(GL_TEXTURE_2D, Font->TextureId);
glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
glTexImage2D(GL_TEXTURE_2D, 0, GL_ALPHA, W, H, 0, GL_ALPHA, GL_UNSIGNED_BYTE, Font->Bitmap);
}
My GL setup:
void InitMain()
{
// OpenGL
glClearColor(0, 0, 0.5f, 1);
glDisable(GL_DEPTH_TEST);
glDisable(GL_LIGHTING);
glDisable(GL_CULL_FACE);
glDepthMask(false);
glEnable(GL_BLEND);
glEnable(GL_LINE_SMOOTH);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
GLenum GLError = glGetError();
if (GLError != GL_NO_ERROR)
{
printf("GL Error: %s\n", glGetString(GLError));
}
// Fonts
GL.MakeFontFromFile("resources/fonts/cour.ttf", 16, Editor.Fonts+0);
}
void UpdateMain(float dt)
{
FDServices *PS = Editor.PS;
if (GL.ScreenWidth != PS->ScreenWidth ||
GL.ScreenHeight != PS->ScreenHeight)
{
GL.ScreenWidth = PS->ScreenWidth;
GL.ScreenHeight = PS->ScreenHeight;
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(0, GL.ScreenWidth, GL.ScreenHeight, 0, -1, +1);
}
glViewport(0, 0, GL.ScreenWidth, GL.ScreenHeight);
glClear(GL_COLOR_BUFFER_BIT|GL_STENCIL_BUFFER_BIT);
glClearStencil(0);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
GL.DrawTextAt(10, 40, "1 glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);", FDColor(1, 1, 1, 1), Editor.Fonts+0);
}
What am I missing/doing wrong?
Appreciate any help!
Cheers