From 0715639ad24eb946add791315c9305c1e766dddc Mon Sep 17 00:00:00 2001 From: Thomas Friedel Date: Thu, 25 Jan 2018 15:50:05 +0100 Subject: [PATCH] rearranged things a bit --- canvas.go | 249 ++++++++++++++++++++---------------------------------- images.go | 46 ++++++++++ opengl.go | 90 -------------------- paths.go | 120 ++++++++++++++++++++++++++ text.go | 5 -- 5 files changed, 257 insertions(+), 253 deletions(-) delete mode 100644 opengl.go create mode 100644 paths.go diff --git a/canvas.go b/canvas.go index 96cb322..6eb7694 100644 --- a/canvas.go +++ b/canvas.go @@ -1,6 +1,7 @@ package canvas import ( + "fmt" "image" "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 func (cv *Canvas) SetFillColor(value ...interface{}) { r, g, b, a, ok := parseColor(value...) @@ -89,6 +174,12 @@ func (cv *Canvas) SetLineWidth(width float32) { 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 func (cv *Canvas) FillRect(x, y, w, h float32) { cv.activate() @@ -108,161 +199,3 @@ func (cv *Canvas) FillRect(x, y, w, h float32) { gli.DrawArrays(gl_TRIANGLE_FAN, 0, 4) 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) -} diff --git a/images.go b/images.go index 343c6fc..ea49003 100644 --- a/images.go +++ b/images.go @@ -5,6 +5,7 @@ import ( "errors" "image" "io/ioutil" + "unsafe" ) 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) H() int { return 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) +} diff --git a/opengl.go b/opengl.go deleted file mode 100644 index 3194068..0000000 --- a/opengl.go +++ /dev/null @@ -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); -}` diff --git a/paths.go b/paths.go new file mode 100644 index 0000000..11276d9 --- /dev/null +++ b/paths.go @@ -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) +} diff --git a/text.go b/text.go index a450314..da59338 100644 --- a/text.go +++ b/text.go @@ -41,11 +41,6 @@ func LoadFont(src interface{}) (*Font, error) { 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) { cv.activate()