ebiten/graphics/opengl/offscreen/offscreen.go
2014-01-08 14:54:12 +09:00

100 lines
2.9 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"
)
type Offscreen struct {
screenHeight int
screenScale int
mainFramebufferTexture *rendertarget.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 *rendertarget.RenderTarget) {
C.glFlush()
// TODO: Calc x, y, width, heigth at another function
o.doSet(rt.Framebuffer, 0, 0,
graphics.AdjustSizeForTexture(rt.Width), graphics.AdjustSizeForTexture(rt.Height))
}
func (o *Offscreen) SetMainFramebuffer() {
o.Set(o.mainFramebufferTexture)
}
func (o *Offscreen) DrawTexture(texture *texture.Texture,
geometryMatrix matrix.Geometry, colorMatrix matrix.Color) {
quad := graphics.TextureQuadForTexture(texture.Width, texture.Height)
shader.DrawTexture(texture.Native,
o.projectionMatrix, []graphics.TextureQuad{quad},
geometryMatrix, colorMatrix)
}
func (o *Offscreen) DrawTextureParts(texture *texture.Texture,
parts []graphics.TexturePart,
geometryMatrix matrix.Geometry, colorMatrix matrix.Color) {
quads := graphics.TextureQuadsForTextureParts(parts, texture.Width, texture.Height)
shader.DrawTexture(texture.Native,
o.projectionMatrix, quads,
geometryMatrix, colorMatrix)
}
func (o *Offscreen) doSet(framebuffer rendertarget.Framebuffer, x, y, width, height int) {
C.glBindFramebuffer(C.GL_FRAMEBUFFER, C.GLuint(framebuffer))
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 framebuffer == o.mainFramebufferTexture.Framebuffer {
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(height) * 2
}
for j := 0; j < 4; j++ {
for i := 0; i < 4; i++ {
o.projectionMatrix[i+j*4] = float32(matrix[i][j])
}
}
}