// update handles user input. func (rt *rtrace) update(dev device.Device) { pressed := dev.Update() if pressed.Resized { _, _, ww, wh := dev.Size() gl.Viewport(0, 0, int32(ww), int32(wh)) } }
// resize handles user screen/window changes. func (ld *ldtag) resize(x, y, width, height int) { gl.Viewport(0, 0, int32(width), int32(height)) ld.persp.Persp(60, float64(width)/float64(height), 0.1, 50) }
// resize handles user screen/window changes. func (sf *sftag) resize(x, y, width, height int) { gl.Viewport(0, 0, int32(width), int32(height)) }
// Render implementation. // FUTURE: all kinds of possible optimizations that would need to be // profiled before implementing. // • group by vao to avoid switching vao's. // • group by texture to avoid switching textures. // • use interleaved vertex data. // • uniform buffers http://www.opengl.org/wiki/Uniform_Buffer_Object. // • ... lots more possiblities... leave your fav here. func (gc *opengl) Render(dr Draw) { d, ok := dr.(*draw) if !ok || d == nil { return } // switch state only if necessary. if gc.depthTest != d.depth { if d.depth { gl.Enable(gl.DEPTH_TEST) } else { gl.Disable(gl.DEPTH_TEST) } gc.depthTest = d.depth } // switch render framebuffer only if necessary. The framebuffer // is used to render to a texture associated with a framebuffer. if gc.fbo != d.fbo { gl.BindFramebuffer(gl.FRAMEBUFFER, d.fbo) if d.fbo == 0 { gl.Viewport(0, 0, gc.vw, gc.vh) } else { gl.Clear(gl.DEPTH_BUFFER_BIT) gl.Viewport(0, 0, 1024, 1024) // size convention for framebuffer texture. } gc.fbo = d.fbo } // switch shaders only if necessary. if gc.shader != d.shader { gl.UseProgram(d.shader) gc.shader = d.shader } // Ask the model to bind its provisioned uniforms. // FUTURE: only need to bind uniforms that have changed. gc.bindUniforms(d) // bind the data buffers and render. gl.BindVertexArray(d.vao) switch d.mode { case LINES: gl.PolygonMode(gl.FRONT_AND_BACK, gl.LINE) gl.DrawElements(gl.LINES, d.numFaces, gl.UNSIGNED_SHORT, 0) gl.PolygonMode(gl.FRONT_AND_BACK, gl.FILL) case POINTS: gl.Enable(gl.PROGRAM_POINT_SIZE) gl.DrawArrays(gl.POINTS, 0, d.numVerts) gl.Disable(gl.PROGRAM_POINT_SIZE) case TRIANGLES: if len(d.texs) > 1 && d.texs[0].fn > 0 { // Multiple textures on one model specify which verticies they apply to. for _, tex := range d.texs { // Use the same texture unit and sampler. Just update which // image is being sampled. gl.BindTexture(gl.TEXTURE_2D, tex.tid) // fn is the number of triangles, 3 indicies per triangle. // f0 is the offset in triangles where each triangle has 3 indicies // of 2 bytes (uShort) each. gl.DrawElements(gl.TRIANGLES, tex.fn*3, gl.UNSIGNED_SHORT, int64(3*2*tex.f0)) } } else { // Single textures are handled with a standard bindUniforms gl.DrawElements(gl.TRIANGLES, d.numFaces, gl.UNSIGNED_SHORT, 0) } } }
func (gc *opengl) Viewport(width int, height int) { gc.vw, gc.vh = int32(width), int32(height) gl.Viewport(0, 0, int32(width), int32(height)) }
// resize sets the view port size. User resizes are ignored. func (tag *trtag) resize(width int, height int) { gl.Viewport(0, 0, int32(width), int32(height)) tag.persp.Persp(60, float64(width)/float64(height), 0.1, 50) }