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rearranged things a bit

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This commit is contained in:
Thomas Friedel 2018-01-25 15:50:05 +01:00
parent 85667e8f57
commit 0715639ad2
5 changed files with 257 additions and 253 deletions
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249
canvas.go
View file

@ -1,6 +1,7 @@
package canvas package canvas
import ( import (
"fmt"
"image" "image"
"unsafe" "unsafe"
@ -68,6 +69,90 @@ func (cv *Canvas) activate() {
} }
} }
var (
gli GL
buf uint32
sr *solidShader
tr *textureShader
)
func LoadGL(glimpl GL) (err error) {
gli = glimpl
gli.GetError() // clear error state
sr, err = loadSolidShader()
if err != nil {
return
}
err = glError()
if err != nil {
return
}
tr, err = loadTextureShader()
if err != nil {
return
}
err = glError()
if err != nil {
return
}
gli.GenBuffers(1, &buf)
err = glError()
if err != nil {
return
}
gli.Enable(gl_BLEND)
gli.BlendFunc(gl_SRC_ALPHA, gl_ONE_MINUS_SRC_ALPHA)
return
}
//go:generate go run make_shaders.go
//go:generate go fmt
var solidVS = `
attribute vec2 vertex;
void main() {
gl_Position = vec4(vertex, 0.0, 1.0);
}`
var solidFS = `
#ifdef GL_ES
precision mediump float;
#endif
uniform vec4 color;
void main() {
gl_FragColor = color;
}`
var textureVS = `
attribute vec2 vertex, texCoord;
varying vec2 v_texCoord;
void main() {
v_texCoord = texCoord;
gl_Position = vec4(vertex, 0.0, 1.0);
}`
var textureFS = `
#ifdef GL_ES
precision mediump float;
#endif
varying vec2 v_texCoord;
uniform sampler2D image;
void main() {
gl_FragColor = texture2D(image, v_texCoord);
}`
func glError() error {
glErr := gli.GetError()
if glErr != gl_NO_ERROR {
return fmt.Errorf("GL Error: %x", glErr)
}
return nil
}
// SetFillColor sets the color for any fill calls // SetFillColor sets the color for any fill calls
func (cv *Canvas) SetFillColor(value ...interface{}) { func (cv *Canvas) SetFillColor(value ...interface{}) {
r, g, b, a, ok := parseColor(value...) r, g, b, a, ok := parseColor(value...)
@ -89,6 +174,12 @@ func (cv *Canvas) SetLineWidth(width float32) {
cv.stroke.lineWidth = width cv.stroke.lineWidth = width
} }
// SetFont sets the font and font size
func (cv *Canvas) SetFont(font *Font, size float32) {
cv.text.font = font
cv.text.size = size
}
// FillRect fills a rectangle with the active color // FillRect fills a rectangle with the active color
func (cv *Canvas) FillRect(x, y, w, h float32) { func (cv *Canvas) FillRect(x, y, w, h float32) {
cv.activate() cv.activate()
@ -108,161 +199,3 @@ func (cv *Canvas) FillRect(x, y, w, h float32) {
gli.DrawArrays(gl_TRIANGLE_FAN, 0, 4) gli.DrawArrays(gl_TRIANGLE_FAN, 0, 4)
gli.DisableVertexAttribArray(sr.vertex) gli.DisableVertexAttribArray(sr.vertex)
} }
func (cv *Canvas) BeginPath() {
if cv.path == nil {
cv.path = make([]pathPoint, 0, 100)
}
cv.path = cv.path[:0]
}
func (cv *Canvas) MoveTo(x, y float32) {
cv.path = append(cv.path, pathPoint{pos: lm.Vec2{x, y}, move: true})
}
func (cv *Canvas) LineTo(x, y float32) {
cv.path = append(cv.path, pathPoint{pos: lm.Vec2{x, y}, move: false})
}
func (cv *Canvas) ClosePath() {
if len(cv.path) == 0 {
return
}
cv.path = append(cv.path, pathPoint{pos: cv.path[0].pos, move: false})
}
func (cv *Canvas) Stroke() {
if len(cv.path) == 0 {
return
}
cv.activate()
gli.Enable(gl_STENCIL_TEST)
gli.ColorMask(false, false, false, false)
gli.StencilFunc(gl_ALWAYS, 1, 0xFF)
gli.StencilOp(gl_KEEP, gl_KEEP, gl_REPLACE)
gli.StencilMask(0xFF)
gli.Clear(gl_STENCIL_BUFFER_BIT)
gli.UseProgram(sr.id)
gli.Uniform4f(sr.color, cv.stroke.r, cv.stroke.g, cv.stroke.b, cv.stroke.a)
gli.EnableVertexAttribArray(sr.vertex)
gli.BindBuffer(gl_ARRAY_BUFFER, buf)
var buf [1000]float32
tris := buf[:0]
tris = append(tris, -1, -1, -1, 1, 1, 1, -1, -1, 1, 1, 1, -1)
p0 := cv.path[0].pos
for _, p := range cv.path {
if p.move {
p0 = p.pos
continue
}
p1 := p.pos
v1 := p1.Sub(p0).Norm()
v2 := lm.Vec2{v1[1], -v1[0]}.MulF(cv.stroke.lineWidth * 0.5)
v1 = v1.MulF(cv.stroke.lineWidth * 0.5)
x0f, y0f := cv.vecToGL(p0.Sub(v1).Add(v2))
x1f, y1f := cv.vecToGL(p1.Add(v1).Add(v2))
x2f, y2f := cv.vecToGL(p1.Add(v1).Sub(v2))
x3f, y3f := cv.vecToGL(p0.Sub(v1).Sub(v2))
tris = append(tris, x0f, y0f, x1f, y1f, x2f, y2f, x0f, y0f, x2f, y2f, x3f, y3f)
p0 = p1
}
gli.BufferData(gl_ARRAY_BUFFER, len(tris)*4, unsafe.Pointer(&tris[0]), gl_STREAM_DRAW)
gli.VertexAttribPointer(sr.vertex, 2, gl_FLOAT, false, 0, nil)
gli.DrawArrays(gl_TRIANGLES, 6, int32(len(tris)/2-6))
gli.ColorMask(true, true, true, true)
gli.StencilFunc(gl_EQUAL, 1, 0xFF)
gli.StencilMask(0)
gli.DrawArrays(gl_TRIANGLE_FAN, 0, 6)
gli.DisableVertexAttribArray(sr.vertex)
gli.Disable(gl_STENCIL_TEST)
}
func (cv *Canvas) Fill() {
if len(cv.path) < 3 {
return
}
cv.activate()
gli.UseProgram(sr.id)
gli.Uniform4f(sr.color, cv.fill.r, cv.fill.g, cv.fill.b, cv.fill.a)
gli.EnableVertexAttribArray(sr.vertex)
gli.BindBuffer(gl_ARRAY_BUFFER, buf)
var buf [1000]float32
tris := buf[:0]
tris = append(tris, -1, -1, -1, 1, 1, 1, -1, -1, 1, 1, 1, -1)
tris = triangulatePath(cv.path, tris)
total := len(tris)
for i := 12; i < total; i += 2 {
x, y := tris[i], tris[i+1]
tris[i], tris[i+1] = cv.ptToGL(x, y)
}
gli.BufferData(gl_ARRAY_BUFFER, len(tris)*4, unsafe.Pointer(&tris[0]), gl_STREAM_DRAW)
gli.VertexAttribPointer(sr.vertex, 2, gl_FLOAT, false, 0, nil)
gli.DrawArrays(gl_TRIANGLES, 6, int32(len(tris)/2-6))
gli.DisableVertexAttribArray(sr.vertex)
}
func (cv *Canvas) DrawImage(img *Image, coords ...float32) {
var sx, sy, sw, sh, dx, dy, dw, dh float32
sw, sh = float32(img.w), float32(img.h)
dw, dh = float32(img.w), float32(img.h)
if len(coords) == 2 {
dx, dy = coords[0], coords[1]
} else if len(coords) == 4 {
dx, dy = coords[0], coords[1]
dw, dh = coords[2], coords[3]
} else if len(coords) == 8 {
sx, sy = coords[0], coords[1]
sw, sh = coords[2], coords[3]
dx, dy = coords[4], coords[5]
dw, dh = coords[6], coords[7]
}
dx0, dy0 := cv.ptToGL(dx, dy)
dx1, dy1 := cv.ptToGL(dx+dw, dy+dh)
sx /= float32(img.w)
sy /= float32(img.h)
sw /= float32(img.w)
sh /= float32(img.h)
cv.activate()
gli.UseProgram(tr.id)
gli.ActiveTexture(gl_TEXTURE0)
gli.BindTexture(gl_TEXTURE_2D, img.tex)
gli.Uniform1i(tr.image, 0)
gli.BindBuffer(gl_ARRAY_BUFFER, buf)
data := [16]float32{dx0, dy0, dx0, dy1, dx1, dy1, dx1, dy0,
sx, sy, sx, sy + sh, sx + sw, sy + sh, sx + sw, sy}
gli.BufferData(gl_ARRAY_BUFFER, len(data)*4, unsafe.Pointer(&data[0]), gl_STREAM_DRAW)
gli.VertexAttribPointer(tr.vertex, 2, gl_FLOAT, false, 0, nil)
gli.VertexAttribPointer(tr.texCoord, 2, gl_FLOAT, false, 0, gli.PtrOffset(8*4))
gli.EnableVertexAttribArray(tr.vertex)
gli.EnableVertexAttribArray(tr.texCoord)
gli.DrawArrays(gl_TRIANGLE_FAN, 0, 4)
gli.DisableVertexAttribArray(tr.vertex)
gli.DisableVertexAttribArray(tr.texCoord)
}

46
images.go
View file

@ -5,6 +5,7 @@ import (
"errors" "errors"
"image" "image"
"io/ioutil" "io/ioutil"
"unsafe"
) )
type Image struct { type Image struct {
@ -140,3 +141,48 @@ func loadImageConverted(src image.Image) (*Image, error) {
func (img *Image) W() int { return img.w } func (img *Image) W() int { return img.w }
func (img *Image) H() int { return img.h } func (img *Image) H() int { return img.h }
func (img *Image) Size() (int, int) { return img.w, img.h } func (img *Image) Size() (int, int) { return img.w, img.h }
func (cv *Canvas) DrawImage(img *Image, coords ...float32) {
var sx, sy, sw, sh, dx, dy, dw, dh float32
sw, sh = float32(img.w), float32(img.h)
dw, dh = float32(img.w), float32(img.h)
if len(coords) == 2 {
dx, dy = coords[0], coords[1]
} else if len(coords) == 4 {
dx, dy = coords[0], coords[1]
dw, dh = coords[2], coords[3]
} else if len(coords) == 8 {
sx, sy = coords[0], coords[1]
sw, sh = coords[2], coords[3]
dx, dy = coords[4], coords[5]
dw, dh = coords[6], coords[7]
}
dx0, dy0 := cv.ptToGL(dx, dy)
dx1, dy1 := cv.ptToGL(dx+dw, dy+dh)
sx /= float32(img.w)
sy /= float32(img.h)
sw /= float32(img.w)
sh /= float32(img.h)
cv.activate()
gli.UseProgram(tr.id)
gli.ActiveTexture(gl_TEXTURE0)
gli.BindTexture(gl_TEXTURE_2D, img.tex)
gli.Uniform1i(tr.image, 0)
gli.BindBuffer(gl_ARRAY_BUFFER, buf)
data := [16]float32{dx0, dy0, dx0, dy1, dx1, dy1, dx1, dy0,
sx, sy, sx, sy + sh, sx + sw, sy + sh, sx + sw, sy}
gli.BufferData(gl_ARRAY_BUFFER, len(data)*4, unsafe.Pointer(&data[0]), gl_STREAM_DRAW)
gli.VertexAttribPointer(tr.vertex, 2, gl_FLOAT, false, 0, nil)
gli.VertexAttribPointer(tr.texCoord, 2, gl_FLOAT, false, 0, gli.PtrOffset(8*4))
gli.EnableVertexAttribArray(tr.vertex)
gli.EnableVertexAttribArray(tr.texCoord)
gli.DrawArrays(gl_TRIANGLE_FAN, 0, 4)
gli.DisableVertexAttribArray(tr.vertex)
gli.DisableVertexAttribArray(tr.texCoord)
}

90
opengl.go
View file

@ -1,90 +0,0 @@
package canvas
import (
"fmt"
)
var gli GL
//go:generate go run make_shaders.go
//go:generate go fmt
func glError() error {
glErr := gli.GetError()
if glErr != gl_NO_ERROR {
return fmt.Errorf("GL Error: %x", glErr)
}
return nil
}
var (
buf uint32
sr *solidShader
tr *textureShader
)
func LoadGL(glimpl GL) (err error) {
gli = glimpl
gli.GetError() // clear error state
sr, err = loadSolidShader()
if err != nil {
return
}
err = glError()
if err != nil {
return
}
tr, err = loadTextureShader()
if err != nil {
return
}
err = glError()
if err != nil {
return
}
gli.GenBuffers(1, &buf)
err = glError()
if err != nil {
return
}
gli.Enable(gl_BLEND)
gli.BlendFunc(gl_SRC_ALPHA, gl_ONE_MINUS_SRC_ALPHA)
return
}
var solidVS = `
attribute vec2 vertex;
void main() {
gl_Position = vec4(vertex, 0.0, 1.0);
}`
var solidFS = `
#ifdef GL_ES
precision mediump float;
#endif
uniform vec4 color;
void main() {
gl_FragColor = color;
}`
var textureVS = `
attribute vec2 vertex, texCoord;
varying vec2 v_texCoord;
void main() {
v_texCoord = texCoord;
gl_Position = vec4(vertex, 0.0, 1.0);
}`
var textureFS = `
#ifdef GL_ES
precision mediump float;
#endif
varying vec2 v_texCoord;
uniform sampler2D image;
void main() {
gl_FragColor = texture2D(image, v_texCoord);
}`

120
paths.go Normal file
View file

@ -0,0 +1,120 @@
package canvas
import (
"unsafe"
"github.com/tfriedel6/lm"
)
func (cv *Canvas) BeginPath() {
if cv.path == nil {
cv.path = make([]pathPoint, 0, 100)
}
cv.path = cv.path[:0]
}
func (cv *Canvas) MoveTo(x, y float32) {
cv.path = append(cv.path, pathPoint{pos: lm.Vec2{x, y}, move: true})
}
func (cv *Canvas) LineTo(x, y float32) {
cv.path = append(cv.path, pathPoint{pos: lm.Vec2{x, y}, move: false})
}
func (cv *Canvas) ClosePath() {
if len(cv.path) == 0 {
return
}
cv.path = append(cv.path, pathPoint{pos: cv.path[0].pos, move: false})
}
func (cv *Canvas) Stroke() {
if len(cv.path) == 0 {
return
}
cv.activate()
gli.Enable(gl_STENCIL_TEST)
gli.ColorMask(false, false, false, false)
gli.StencilFunc(gl_ALWAYS, 1, 0xFF)
gli.StencilOp(gl_KEEP, gl_KEEP, gl_REPLACE)
gli.StencilMask(0xFF)
gli.Clear(gl_STENCIL_BUFFER_BIT)
gli.UseProgram(sr.id)
gli.Uniform4f(sr.color, cv.stroke.r, cv.stroke.g, cv.stroke.b, cv.stroke.a)
gli.EnableVertexAttribArray(sr.vertex)
gli.BindBuffer(gl_ARRAY_BUFFER, buf)
var buf [1000]float32
tris := buf[:0]
tris = append(tris, -1, -1, -1, 1, 1, 1, -1, -1, 1, 1, 1, -1)
p0 := cv.path[0].pos
for _, p := range cv.path {
if p.move {
p0 = p.pos
continue
}
p1 := p.pos
v1 := p1.Sub(p0).Norm()
v2 := lm.Vec2{v1[1], -v1[0]}.MulF(cv.stroke.lineWidth * 0.5)
v1 = v1.MulF(cv.stroke.lineWidth * 0.5)
x0f, y0f := cv.vecToGL(p0.Sub(v1).Add(v2))
x1f, y1f := cv.vecToGL(p1.Add(v1).Add(v2))
x2f, y2f := cv.vecToGL(p1.Add(v1).Sub(v2))
x3f, y3f := cv.vecToGL(p0.Sub(v1).Sub(v2))
tris = append(tris, x0f, y0f, x1f, y1f, x2f, y2f, x0f, y0f, x2f, y2f, x3f, y3f)
p0 = p1
}
gli.BufferData(gl_ARRAY_BUFFER, len(tris)*4, unsafe.Pointer(&tris[0]), gl_STREAM_DRAW)
gli.VertexAttribPointer(sr.vertex, 2, gl_FLOAT, false, 0, nil)
gli.DrawArrays(gl_TRIANGLES, 6, int32(len(tris)/2-6))
gli.ColorMask(true, true, true, true)
gli.StencilFunc(gl_EQUAL, 1, 0xFF)
gli.StencilMask(0)
gli.DrawArrays(gl_TRIANGLE_FAN, 0, 6)
gli.DisableVertexAttribArray(sr.vertex)
gli.Disable(gl_STENCIL_TEST)
}
func (cv *Canvas) Fill() {
if len(cv.path) < 3 {
return
}
cv.activate()
gli.UseProgram(sr.id)
gli.Uniform4f(sr.color, cv.fill.r, cv.fill.g, cv.fill.b, cv.fill.a)
gli.EnableVertexAttribArray(sr.vertex)
gli.BindBuffer(gl_ARRAY_BUFFER, buf)
var buf [1000]float32
tris := buf[:0]
tris = append(tris, -1, -1, -1, 1, 1, 1, -1, -1, 1, 1, 1, -1)
tris = triangulatePath(cv.path, tris)
total := len(tris)
for i := 12; i < total; i += 2 {
x, y := tris[i], tris[i+1]
tris[i], tris[i+1] = cv.ptToGL(x, y)
}
gli.BufferData(gl_ARRAY_BUFFER, len(tris)*4, unsafe.Pointer(&tris[0]), gl_STREAM_DRAW)
gli.VertexAttribPointer(sr.vertex, 2, gl_FLOAT, false, 0, nil)
gli.DrawArrays(gl_TRIANGLES, 6, int32(len(tris)/2-6))
gli.DisableVertexAttribArray(sr.vertex)
}

5
text.go
View file

@ -41,11 +41,6 @@ func LoadFont(src interface{}) (*Font, error) {
return nil, errors.New("Unsupported source type") return nil, errors.New("Unsupported source type")
} }
func (cv *Canvas) SetFont(font *Font, size float32) {
cv.text.font = font
cv.text.size = size
}
func (cv *Canvas) FillText(str string, x, y float32) { func (cv *Canvas) FillText(str string, x, y float32) {
cv.activate() cv.activate()