Add image.ReplacePixels; Add example/noise (#89)

This commit is contained in:
Hajime Hoshi 2015-01-20 23:58:58 +09:00
parent d2d32d3956
commit d994f34d53
6 changed files with 121 additions and 6 deletions

69
example/noise/main.go Normal file
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@ -0,0 +1,69 @@
// Copyright 2014 Hajime Hoshi
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package main
import (
"fmt"
"github.com/hajimehoshi/ebiten"
"github.com/hajimehoshi/ebiten/ebitenutil"
"image"
"log"
//"math/rand"
)
const (
screenWidth = 320
screenHeight = 240
)
var (
noiseImage *image.RGBA
)
type rand struct {
x, y, z, w uint32
}
func (r *rand) next() uint32 {
// math/rand is too slow to keep 60 FPS on web browsers.
// Use Xorshift instead: http://en.wikipedia.org/wiki/Xorshift
t := r.x ^ (r.x << 11)
r.x, r.y, r.z = r.y, r.z, r.w
r.w = (r.w ^ (r.w >> 19)) ^ (t ^ (t >> 8))
return r.w
}
var randInstance = &rand{12345678, 4185243, 776511, 45411}
func update(screen *ebiten.Image) error {
const l = screenWidth * screenHeight
for i := 0; i < l; i++ {
x := randInstance.next()
noiseImage.Pix[4*i] = uint8(x >> 24)
noiseImage.Pix[4*i+1] = uint8(x >> 16)
noiseImage.Pix[4*i+2] = uint8(x >> 8)
noiseImage.Pix[4*i+3] = 0xff
}
screen.ReplacePixels(noiseImage.Pix)
ebitenutil.DebugPrint(screen, fmt.Sprintf("FPS: %f", ebiten.CurrentFPS()))
return nil
}
func main() {
noiseImage = image.NewRGBA(image.Rect(0, 0, screenWidth, screenHeight))
if err := ebiten.Run(update, screenWidth, screenHeight, 2, "Noise (Ebiten Demo)"); err != nil {
log.Fatal(err)
}
}

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@ -69,6 +69,11 @@ func IsGamepadButtonPressed(id int, button GamepadButton) bool {
} }
// NewImage returns an empty image. // NewImage returns an empty image.
//
// NewImage generates a new texture and a new framebuffer.
// Be careful that image objects will never be released
// even though nothing refers the image object and GC works.
// It is because there is no way to define finalizers for Go objects if you use GopherJS.
func NewImage(width, height int, filter Filter) (*Image, error) { func NewImage(width, height int, filter Filter) (*Image, error) {
var img *Image var img *Image
var err error var err error

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@ -16,6 +16,7 @@ package ebiten
import ( import (
"errors" "errors"
"fmt"
"github.com/hajimehoshi/ebiten/internal" "github.com/hajimehoshi/ebiten/internal"
"github.com/hajimehoshi/ebiten/internal/graphics" "github.com/hajimehoshi/ebiten/internal/graphics"
"github.com/hajimehoshi/ebiten/internal/opengl" "github.com/hajimehoshi/ebiten/internal/opengl"
@ -162,6 +163,26 @@ func (i *Image) At(x, y int) color.Color {
return color.RGBA{r, g, b, a} return color.RGBA{r, g, b, a}
} }
// ReplacePixels replaces the pixels of image with p.
//
// The given p must represent RGBA pre-multiplied alpha values.
//
// len(p) must equal to 4 * (image width) * (image height)
//
// This function may be slow.
func (i *Image) ReplacePixels(p []uint8) error {
w, h := i.Size()
l := 4 * w * h
if len(p) != l {
return errors.New(fmt.Sprintf("p's length must be %d", l))
}
var err error
ui.Use(func(c *opengl.Context) {
err = i.texture.ReplacePixels(c, p)
})
return err
}
// A DrawImageOptions represents options to render an image on an image. // A DrawImageOptions represents options to render an image on an image.
type DrawImageOptions struct { type DrawImageOptions struct {
ImageParts ImageParts ImageParts ImageParts

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@ -90,3 +90,9 @@ func NewTextureFromImage(c *opengl.Context, img image.Image, filter opengl.Filte
func (t *Texture) Dispose(c *opengl.Context) { func (t *Texture) Dispose(c *opengl.Context) {
c.DeleteTexture(t.native) c.DeleteTexture(t.native)
} }
func (t *Texture) ReplacePixels(c *opengl.Context, p []uint8) error {
c.BindTexture(t.native)
c.TexSubImage2D(p, t.width, t.height)
return nil
}

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@ -105,6 +105,10 @@ func (c *Context) DeleteTexture(t Texture) {
gl.Texture(t).Delete() gl.Texture(t).Delete()
} }
func (c *Context) TexSubImage2D(p []uint8, width, height int) {
gl.TexSubImage2D(gl.TEXTURE_2D, 0, 0, 0, width, height, gl.RGBA, gl.UNSIGNED_BYTE, p)
}
func (c *Context) NewFramebuffer(texture Texture) (Framebuffer, error) { func (c *Context) NewFramebuffer(texture Texture) (Framebuffer, error) {
f := gl.GenFramebuffer() f := gl.GenFramebuffer()
f.Bind() f.Bind()

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@ -103,6 +103,8 @@ func (c *Context) NewTexture(width, height int, pixels []uint8, filter Filter) (
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, int(filter)) gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, int(filter))
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, int(filter)) gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, int(filter))
// TODO: Can we use glTexSubImage2D with linear filtering?
// void texImage2D(GLenum target, GLint level, GLenum internalformat, // void texImage2D(GLenum target, GLint level, GLenum internalformat,
// GLsizei width, GLsizei height, GLint border, GLenum format, // GLsizei width, GLsizei height, GLint border, GLenum format,
// GLenum type, ArrayBufferView? pixels); // GLenum type, ArrayBufferView? pixels);
@ -140,13 +142,12 @@ func (c *Context) DeleteTexture(t Texture) {
gl.DeleteTexture(t.Object) gl.DeleteTexture(t.Object)
} }
func (c *Context) GlslHighpSupported() bool { func (c *Context) TexSubImage2D(p []uint8, width, height int) {
gl := c.gl gl := c.gl
// headless-gl library may not define getShaderPrecisionFormat. // void texSubImage2D(GLenum target, GLint level, GLint xoffset, GLint yoffset,
if gl.Get("getShaderPrecisionFormat") == js.Undefined { // GLsizei width, GLsizei height,
return false // GLenum format, GLenum type, ArrayBufferView? pixels);
} gl.Call("texSubImage2D", gl.TEXTURE_2D, 0, 0, 0, width, height, gl.RGBA, gl.UNSIGNED_BYTE, p)
return gl.Call("getShaderPrecisionFormat", gl.FRAGMENT_SHADER, gl.HIGH_FLOAT).Get("precision").Int() != 0
} }
func (c *Context) NewFramebuffer(t Texture) (Framebuffer, error) { func (c *Context) NewFramebuffer(t Texture) (Framebuffer, error) {
@ -216,6 +217,15 @@ func (c *Context) DeleteShader(s Shader) {
gl.DeleteShader(s.Object) gl.DeleteShader(s.Object)
} }
func (c *Context) GlslHighpSupported() bool {
gl := c.gl
// headless-gl library may not define getShaderPrecisionFormat.
if gl.Get("getShaderPrecisionFormat") == js.Undefined {
return false
}
return gl.Call("getShaderPrecisionFormat", gl.FRAGMENT_SHADER, gl.HIGH_FLOAT).Get("precision").Int() != 0
}
var lastProgramID ProgramID = 0 var lastProgramID ProgramID = 0
func (c *Context) NewProgram(shaders []Shader) (Program, error) { func (c *Context) NewProgram(shaders []Shader) (Program, error) {