ebiten/graphics/opengl/offscreen/offscreen.go
2013-12-12 01:46:56 +09:00

115 lines
3.1 KiB
Go

package offscreen
// #cgo LDFLAGS: -framework OpenGL
//
// #include <stdlib.h>
// #include <OpenGL/gl.h>
import "C"
import (
"fmt"
"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/shader"
"github.com/hajimehoshi/go-ebiten/graphics/opengl/texture"
gtexture "github.com/hajimehoshi/go-ebiten/graphics/texture"
)
type Offscreen struct {
screenHeight int
screenScale int
mainFramebufferTexture *gtexture.RenderTarget
projectionMatrix [16]float32
}
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,
rendertarget.Framebuffer(mainFramebuffer))
if err != nil {
panic("creating main framebuffer failed: " + err.Error())
}
return offscreen
}
func (o *Offscreen) Set(rt *gtexture.RenderTarget) {
C.glFlush()
rt.SetAsOffscreen(&setter{o, rt == o.mainFramebufferTexture})
}
func (o *Offscreen) SetMainFramebuffer() {
o.Set(o.mainFramebufferTexture)
}
func (o *Offscreen) DrawTexture(texture *gtexture.Texture,
geometryMatrix matrix.Geometry, colorMatrix matrix.Color) {
texture.Draw(&drawable{o, geometryMatrix, colorMatrix})
}
func (o *Offscreen) DrawTextureParts(texture *gtexture.Texture,
parts []graphics.TexturePart,
geometryMatrix matrix.Geometry, colorMatrix matrix.Color) {
texture.DrawParts(parts, &drawable{o, geometryMatrix, colorMatrix})
}
func (o *Offscreen) DrawLines(lines []graphics.Line) {
// TODO: Implement!
}
type setter struct {
offscreen *Offscreen
usingMainFramebuffer bool
}
func (s *setter) Set(framebuffer interface{}, x, y, width, height int) {
f := framebuffer.(rendertarget.Framebuffer)
C.glBindFramebuffer(C.GL_FRAMEBUFFER, C.GLuint(f))
err := C.glCheckFramebufferStatus(C.GL_FRAMEBUFFER)
if err != C.GL_FRAMEBUFFER_COMPLETE {
panic(fmt.Sprintf("glBindFramebuffer failed: %d", err))
}
C.glBlendFuncSeparate(C.GL_SRC_ALPHA, C.GL_ONE_MINUS_SRC_ALPHA,
C.GL_ZERO, C.GL_ONE)
C.glViewport(C.GLint(x), C.GLint(y),
C.GLsizei(width), C.GLsizei(height))
matrix := graphics.OrthoProjectionMatrix(x, width, y, height)
if s.usingMainFramebuffer {
actualScreenHeight := s.offscreen.screenHeight * s.offscreen.screenScale
// Flip Y and move to fit with the top of the window.
matrix[1][1] *= -1
matrix[1][3] += float64(actualScreenHeight) / float64(height) * 2
}
for j := 0; j < 4; j++ {
for i := 0; i < 4; i++ {
s.offscreen.projectionMatrix[i+j*4] = float32(matrix[i][j])
}
}
}
type drawable struct {
offscreen *Offscreen
geometryMatrix matrix.Geometry
colorMatrix matrix.Color
}
func (d *drawable) Draw(native interface{}, quads []gtexture.Quad) {
shader.DrawTexture(native.(texture.Native),
d.offscreen.projectionMatrix, quads,
d.geometryMatrix, d.colorMatrix)
}