/
draw_font.go
205 lines (155 loc) · 5.19 KB
/
draw_font.go
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package main
import "gl"
import "sdl/ttf"
// import "math"
import "sdl"
import . "game/common"
import "unsafe"
//import "fmt"
type Font struct {
Height float
font *ttf.Font
// Textures *gl.uint // texture ids
// Listbase gl.uint // id of the first display list id
}
func NewFont(fname string, height int) *Font {
// f.Textures = [12]gl.uint
f := &Font{float(height), ttf.OpenFont(fname, height)}
if f.font == nil {
panic("Couldn't open font " + fname)
}
return f
}
func next_p2(a int) int {
var rval int = 1;
for rval<a { rval<<=1 }
return rval;
}
func (f *Font) DrawText2D(x int, y int, color [3]byte, scale float, txt string) (endw int, endh int) {
gl.LoadIdentity();
// gl.Translatef(0.0, 0.0, -2.0);
glEnable2D()
gl.Disable(gl.DEPTH_TEST)
texture, initial, intermediarya, intermediary, w, h := f.setupTextRendering(color, txt)
locX := gl.GLfloat(x)
locY := gl.GLfloat(y)
wi := gl.GLfloat(w) * gl.GLfloat(scale)
he := gl.GLfloat(h) * gl.GLfloat(scale)
/* Draw a quad at location */
gl.Begin(gl.QUADS);
/* Recall that the origin is in the lower-left corner
That is why the TexCoords specify different corners
than the Vertex coors seem to. */
gl.TexCoord2f(0.0, 1.0);
gl.Vertex2f(locX , locY)
gl.TexCoord2f(1.0, 1.0);
gl.Vertex2f(locX + wi, locY)
gl.TexCoord2f(1.0, 0.0);
gl.Vertex2f(locX + wi, locY + he)
gl.TexCoord2f(0.0, 0.0);
gl.Vertex2f(locX , locY + he)
gl.End();
endw, endh = f.teardownTextRendering(texture, initial, intermediarya, intermediary)
gl.Enable(gl.DEPTH_TEST)
glDisable2D()
return
}
func (f *Font) DrawText3D(pos Vector3, color [3]byte, scale float, txt string) (endw int, endh int) {
gl.LoadIdentity();
// gl.Translatef(gl.GLfloat(pos.X), gl.GLfloat(pos.Y), gl.GLfloat(-4.99));
gl.Translatef(gl.GLfloat(pos.X), gl.GLfloat(pos.Y), gl.GLfloat(-4.99));
gl.Scalef(gl.GLfloat(1.0/64.0 * scale), gl.GLfloat(1.0/64.0 * scale), gl.GLfloat(1.0));
gl.Disable(gl.DEPTH_TEST)
texture, initial, intermediarya, intermediary, w ,h := f.setupTextRendering(color, txt)
wi := gl.GLfloat(w)
he := gl.GLfloat(h)
locX := gl.GLfloat(0) - wi * 0.5
locY := gl.GLfloat(0) - he * 0.5
/* Draw a quad at location */
gl.Begin(gl.QUADS);
/* Recall that the origin is in the lower-left corner
That is why the TexCoords specify different corners
than the Vertex coors seem to. */
gl.Color4f(1.0, 1.0, 0.0, 1.0)
gl.TexCoord2f(0.0, 1.0);
gl.Vertex3f(locX , locY, 0.0)
gl.TexCoord2f(1.0, 1.0);
gl.Vertex3f(locX + wi , locY, 0.0)
gl.TexCoord2f(1.0, 0.0);
gl.Vertex3f(locX + wi, locY + he, 0.0)
gl.TexCoord2f(0.0, 0.0);
gl.Vertex3f(locX , locY + he, 0.0)
gl.End();
endw, endh = f.teardownTextRendering(texture, initial, intermediarya, intermediary)
gl.Enable(gl.DEPTH_TEST)
return
}
func (f *Font) setupTextRendering(color [3]byte, txt string) (gl.GLuint, *sdl.Surface, *sdl.Surface, *sdl.Surface, int, int) {
//
var texture gl.GLuint
/* Use SDL_TTF to render our text */
var col sdl.Color
col.R = color[0]
col.G = color[1]
col.B = color[2]
// get surface with text
initial := ttf.RenderText_Blended(f.font, txt, col)
/* Convert the rendered text to a known format */
w := next_p2(int(initial.W))
h := next_p2(int(initial.H))
intermediarya := sdl.CreateRGBSurface(0, w, h, 32,
0x00ff0000, 0x0000ff00, 0x000000ff, 0xff000000);
var rr *sdl.Rect = nil
intermediarya.Blit(rr, initial, rr);
intermediary := intermediarya.DisplayFormatAlpha()
/* Tell GL about our new texture */
gl.GenTextures(1, &texture);
gl.BindTexture(gl.TEXTURE_2D, texture);
gl.TexImage2D(gl.TEXTURE_2D, 0, 4, gl.GLsizei(w), gl.GLsizei(h), 0, gl.BGRA,
gl.UNSIGNED_BYTE, unsafe.Pointer(intermediary.Pixels) );
gl.TexEnvi( gl.TEXTURE_ENV, gl.TEXTURE_ENV_MODE, gl.MODULATE );
/* GL_NEAREST looks horrible, if scaled... */
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR);
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR);
/* prepare to render our texture */
gl.Enable(gl.TEXTURE_2D);
gl.BindTexture(gl.TEXTURE_2D, texture);
gl.Color4f(1.0, 1.0, 1.0, 1.0);
gl.Enable(gl.BLEND)
// gl.BlendFunc(gl.SRC_ALPHA, gl.ONE_MINUS_SRC_ALPHA)
gl.BlendFunc(gl.ONE, gl.ONE_MINUS_SRC_COLOR) // TODO : MAke real alpha work!
return texture, initial, intermediarya, intermediary, w, h
}
func (f *Font) teardownTextRendering(texture gl.GLuint, initial *sdl.Surface, intermediarya *sdl.Surface, intermediary *sdl.Surface) (endw int, endh int) {
//
gl.Disable(gl.BLEND)
/* Bad things happen if we delete the texture before it finishes */
gl.Finish();
/* return the deltas in the unused w,h part of the rect */
endw = int(initial.W)
endh = int(initial.H)
/* Clean up */
initial.Free()
intermediarya.Free()
intermediary.Free()
gl.DeleteTextures(1, &texture);
//
return
}
func glEnable2D() {
var vPort [4]gl.GLint
gl.GetIntegerv(gl.VIEWPORT, &vPort[0]);
gl.MatrixMode(gl.PROJECTION);
gl.PushMatrix();
gl.LoadIdentity();
gl.Ortho(0.0, gl.GLdouble(vPort[2]), 0.0, gl.GLdouble(vPort[3]), -1.0, 1.0);
gl.MatrixMode(gl.MODELVIEW);
gl.PushMatrix();
gl.LoadIdentity();
}
func glDisable2D() {
gl.MatrixMode(gl.PROJECTION);
gl.PopMatrix();
gl.MatrixMode(gl.MODELVIEW);
gl.PopMatrix();
}