ebiten/graphics/opengl/offscreen/offscreen.go
2014-01-08 18:03:21 +09:00

85 lines
2.4 KiB
Go

package offscreen
// #cgo LDFLAGS: -framework OpenGL
//
// #include <stdlib.h>
// #include <OpenGL/gl.h>
import "C"
import (
"github.com/hajimehoshi/go-ebiten/graphics"
"github.com/hajimehoshi/go-ebiten/graphics/matrix"
"github.com/hajimehoshi/go-ebiten/graphics/opengl/rendertarget"
"github.com/hajimehoshi/go-ebiten/graphics/opengl/texture"
)
type Offscreen struct {
screenHeight int
screenScale int
currentRenderTarget *rendertarget.RenderTarget
mainFramebufferTexture *rendertarget.RenderTarget
}
func New(screenWidth, screenHeight, screenScale int) *Offscreen {
offscreen := &Offscreen{
screenHeight: screenHeight,
screenScale: screenScale,
}
mainFramebuffer := C.GLint(0)
C.glGetIntegerv(C.GL_FRAMEBUFFER_BINDING, &mainFramebuffer)
var err error
offscreen.mainFramebufferTexture, err = rendertarget.CreateWithFramebuffer(
screenWidth*screenScale,
screenHeight*screenScale,
texture.Framebuffer(mainFramebuffer))
if err != nil {
panic("creating main framebuffer failed: " + err.Error())
}
offscreen.currentRenderTarget = offscreen.mainFramebufferTexture
return offscreen
}
func (o *Offscreen) Set(rt *rendertarget.RenderTarget) {
C.glFlush()
o.currentRenderTarget = rt
rt.SetAsViewport()
}
func (o *Offscreen) SetMainFramebuffer() {
o.Set(o.mainFramebufferTexture)
}
func (o *Offscreen) DrawTexture(texture *texture.Texture,
geometryMatrix matrix.Geometry, colorMatrix matrix.Color) {
projectionMatrix := o.projectionMatrix()
texture.Draw(projectionMatrix, geometryMatrix, colorMatrix)
}
func (o *Offscreen) DrawTextureParts(texture *texture.Texture,
parts []graphics.TexturePart,
geometryMatrix matrix.Geometry, colorMatrix matrix.Color) {
projectionMatrix := o.projectionMatrix()
texture.DrawParts(parts, projectionMatrix, geometryMatrix, colorMatrix)
}
func (o *Offscreen) projectionMatrix() [16]float32 {
matrix := o.currentRenderTarget.ProjectionMatrix()
if o.currentRenderTarget == o.mainFramebufferTexture {
actualScreenHeight := o.screenHeight * o.screenScale
// Flip Y and move to fit with the top of the window.
matrix[1][1] *= -1
matrix[1][3] += float64(actualScreenHeight) /
float64(graphics.AdjustSizeForTexture(actualScreenHeight)) * 2
}
projectionMatrix := [16]float32{}
for j := 0; j < 4; j++ {
for i := 0; i < 4; i++ {
projectionMatrix[i+j*4] = float32(matrix[i][j])
}
}
return projectionMatrix
}