// drawScene renders the 3D models consisting of one VAO
func (tag *trtag) drawScene() {
gl.Clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT)
tag.checkError("gl.Clear")
gl.UseProgram(tag.shaders)
tag.checkError("gl.UseProgram")
gl.BindVertexArray(tag.vao)
tag.checkError("gl.BindVertexArray")
// Use a modelview matrix and quaternion to rotate the 3D object.
tag.mvp64.SetQ(lin.NewQ().SetAa(0, 1, 0, lin.Rad(-tag.rotateAngle)))
tag.mvp64.TranslateMT(0, 0, -4)
tag.mvp.Set(tag.mvp64.Mult(tag.mvp64, tag.persp))
gl.UniformMatrix4fv(tag.mvpRef, 1, false, tag.mvp.Pointer())
if err := gl.GetError(); err != 0 {
fmt.Printf("gl.UniformMatrix error %d\n", err)
}
gl.DrawElements(gl.TRIANGLES, int32(len(tag.faces)), gl.UNSIGNED_BYTE, 0)
if err := gl.GetError(); err != 0 {
fmt.Printf("gl.DrawElements error %d\n", err)
}
// cleanup
gl.UseProgram(0)
tag.checkError("gl.UseProgram-0")
gl.BindVertexArray(0)
tag.checkError("gl.BindVertexArray-0")
// rotate based on time... not on how fast the computer runs.
if time.Now().Sub(tag.lastTime).Seconds() > 0.01 {
tag.rotateAngle += 1
tag.lastTime = time.Now()
}
}
// bindUniform links data to uniforms expected by shaders.
// It expects the variable parameter list types to match the uniform type.
func (gc *opengl) bindUniform(uniform int32, utype, cnt int, udata ...interface{}) {
switch utype {
case i1:
i1 := udata[0].(int32)
gl.Uniform1i(uniform, i1)
case f1:
f1 := udata[0].(float32)
gl.Uniform1f(uniform, f1)
case f2:
f1 := udata[0].(float32)
f2 := udata[1].(float32)
gl.Uniform2f(uniform, f1, f2)
case f3:
f1 := udata[0].(float32)
f2 := udata[1].(float32)
f3 := udata[2].(float32)
gl.Uniform3f(uniform, f1, f2, f3)
case f4:
f1 := udata[0].(float32)
f2 := udata[1].(float32)
f3 := udata[2].(float32)
f4 := udata[3].(float32)
gl.Uniform4f(uniform, f1, f2, f3, f4)
case x3:
mptr := udata[0].(*float32)
gl.UniformMatrix3fv(uniform, int32(cnt), false, mptr)
case x34:
mptr := udata[0].(*float32)
gl.UniformMatrix3x4fv(uniform, int32(cnt), false, mptr)
case x4:
mptr := udata[0].(*float32)
gl.UniformMatrix4fv(uniform, int32(cnt), false, mptr)
}
}
// drawScene renders the shader-only scene.
func (sf *sftag) drawScene() {
gl.Clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT)
gl.UseProgram(sf.shaders)
gl.BindVertexArray(sf.vao)
timeSinceStart := time.Since(sf.sTime).Seconds()
gl.Uniform1f(sf.gTime, float32(timeSinceStart))
gl.Uniform2f(sf.sizes, 500, 500)
gl.UniformMatrix4fv(sf.mvpref, 1, false, sf.mvp.Pointer())
gl.DrawElements(gl.TRIANGLES, int32(len(sf.faces)), gl.UNSIGNED_BYTE, 0)
// cleanup
gl.UseProgram(0)
gl.BindVertexArray(0)
}
// drawScene renders the single texture on the quad.
func (rt *rtrace) drawScene() {
gl.Clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT)
gl.UseProgram(rt.shaders)
gl.Uniform1i(rt.tex2D, 0)
gl.ActiveTexture(gl.TEXTURE0 + 0)
gl.BindVertexArray(rt.vao)
gl.UniformMatrix4fv(rt.mvpId, 1, false, rt.mvp.Pointer())
gl.DrawElements(gl.TRIANGLES, int32(len(rt.faces)), gl.UNSIGNED_BYTE, 0)
// cleanup
gl.ActiveTexture(0)
gl.UseProgram(0)
gl.BindVertexArray(0)
}
// render draws the scene consisting of one VAO
func (ld *ldtag) render() {
gl.Clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT)
gl.UseProgram(ld.shaders)
gl.BindVertexArray(ld.vao)
// use a model-view-projection matrix
ld.mvp64.Set(lin.M4I).ScaleSM(0.5, 0.5, 0.5).TranslateMT(0, 0, -2)
ld.mvp.Set(ld.mvp64.Mult(ld.mvp64, ld.persp))
gl.UniformMatrix4fv(ld.mvpref, 1, false, ld.mvp.Pointer())
gl.DrawElements(gl.TRIANGLES, ld.faceCount, gl.UNSIGNED_SHORT, 0)
// cleanup
gl.UseProgram(0)
gl.BindVertexArray(0)
}