ebiten/graphics/opengl/context.go
2013-11-29 22:45:18 +09:00

122 lines
3.2 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"
"github.com/hajimehoshi/go-ebiten/graphics/opengl/texture"
"image"
"math"
)
type Context struct {
screenId graphics.RenderTargetId
ids *ids
offscreen *offscreen.Offscreen
}
func newContext(screenWidth, screenHeight, screenScale int) *Context {
context := &Context{
ids: newIds(),
offscreen: offscreen.New(screenWidth, screenHeight, screenScale),
}
var err error
context.screenId, err = context.createRenderTarget(
screenWidth, screenHeight, texture.FilterNearest)
if err != nil {
panic("initializing the offscreen failed: " + err.Error())
}
context.Init()
return context
}
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)
}
// Init initializes the context. The initial state is saved for each GL context.
func (context *Context) Init() {
C.glEnable(C.GL_TEXTURE_2D)
C.glEnable(C.GL_BLEND)
}
func (context *Context) ResetOffscreen() {
context.SetOffscreen(context.screenId)
}
func (context *Context) SetOffscreen(renderTargetId graphics.RenderTargetId) {
renderTarget := context.ids.RenderTargetAt(renderTargetId)
context.offscreen.Set(renderTarget)
}
func (context *Context) setMainFramebufferOffscreen() {
context.offscreen.SetMainFramebuffer()
}
func (context *Context) flush() {
C.glFlush()
}
func (context *Context) createRenderTarget(width, height int, filter texture.Filter) (
graphics.RenderTargetId, error) {
renderTargetId, err := context.ids.CreateRenderTarget(width, height, filter)
if err != nil {
return 0, err
}
return renderTargetId, nil
}
func (context *Context) CreateRenderTarget(width, height int) (
graphics.RenderTargetId, error) {
return context.createRenderTarget(width, height, texture.FilterLinear)
}
func (context *Context) CreateTextureFromImage(img image.Image) (
graphics.TextureId, error) {
return context.ids.CreateTextureFromImage(img)
}