ebiten/graphics/opengl/context.go
2013-12-18 18:05:28 +09:00

109 lines
2.8 KiB
Go

package opengl
// #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/offscreen"
"math"
)
type Context struct {
screenId graphics.RenderTargetId
ids *ids
offscreen *offscreen.Offscreen
screenScale int
}
func newContext(ids *ids, screenWidth, screenHeight, screenScale int) *Context {
context := &Context{
ids: ids,
offscreen: offscreen.New(screenWidth, screenHeight, screenScale),
screenScale: screenScale,
}
var err error
context.screenId, err = ids.CreateRenderTarget(
screenWidth, screenHeight, graphics.FilterNearest)
if err != nil {
panic("initializing the offscreen failed: " + err.Error())
}
context.Clear()
return context
}
func (context *Context) update(draw func(graphics.Context)) {
C.glEnable(C.GL_TEXTURE_2D)
C.glEnable(C.GL_BLEND)
context.ResetOffscreen()
context.Clear()
draw(context)
C.glFlush()
context.offscreen.SetMainFramebuffer()
context.Clear()
scale := float64(context.screenScale)
geometryMatrix := matrix.IdentityGeometry()
geometryMatrix.Scale(scale, scale)
context.DrawRenderTarget(context.screenId,
geometryMatrix, matrix.IdentityColor())
C.glFlush()
}
func (context *Context) Clear() {
context.Fill(0, 0, 0)
}
func (context *Context) Fill(r, g, b uint8) {
const max = float64(math.MaxUint8)
C.glClearColor(
C.GLclampf(float64(r)/max),
C.GLclampf(float64(g)/max),
C.GLclampf(float64(b)/max),
1)
C.glClear(C.GL_COLOR_BUFFER_BIT)
}
func (context *Context) DrawTexture(
id graphics.TextureId,
geometryMatrix matrix.Geometry, colorMatrix matrix.Color) {
tex := context.ids.TextureAt(id)
context.offscreen.DrawTexture(tex, geometryMatrix, colorMatrix)
}
func (context *Context) DrawRenderTarget(
id graphics.RenderTargetId,
geometryMatrix matrix.Geometry, colorMatrix matrix.Color) {
context.DrawTexture(context.ids.ToTexture(id), geometryMatrix, colorMatrix)
}
func (context *Context) DrawTextureParts(
id graphics.TextureId, parts []graphics.TexturePart,
geometryMatrix matrix.Geometry, colorMatrix matrix.Color) {
tex := context.ids.TextureAt(id)
context.offscreen.DrawTextureParts(tex, parts, geometryMatrix, colorMatrix)
}
func (context *Context) DrawRenderTargetParts(
id graphics.RenderTargetId, parts []graphics.TexturePart,
geometryMatrix matrix.Geometry, colorMatrix matrix.Color) {
context.DrawTextureParts(context.ids.ToTexture(id), parts, geometryMatrix, colorMatrix)
}
func (context *Context) ResetOffscreen() {
context.SetOffscreen(context.screenId)
}
func (context *Context) SetOffscreen(renderTargetId graphics.RenderTargetId) {
renderTarget := context.ids.RenderTargetAt(renderTargetId)
context.offscreen.Set(renderTarget)
}