Refactoring

graphics/opengl/shader/program.go

@@ -10,50 +10,60 @@ import (
 	"unsafe"
 )
 
-func createProgram(shaders ...*shader) C.GLuint {
-	program := C.glCreateProgram()
-	for _, shader := range shaders {
-		C.glAttachShader(program, shader.id)
+type program struct {
+	native    C.GLuint
+	shaderIds []shaderId
+}
+
+type programId int
+
+const (
+	programRegular programId = iota
+	programColorMatrix
+)
+
+var programs = map[programId]*program{
+	programRegular: &program{
+		shaderIds: []shaderId{shaderVertex, shaderFragment},
+	},
+	programColorMatrix: &program{
+		shaderIds: []shaderId{shaderVertex, shaderColorMatrix},
+	},
+}
+
+func (p *program) create() {
+	p.native = C.glCreateProgram()
+	if p.native == 0 {
+		panic("glCreateProgram failed")
 	}
-	C.glLinkProgram(program)
+
+	for _, shaderId := range p.shaderIds {
+		C.glAttachShader(p.native, shaders[shaderId].native)
+	}
+	C.glLinkProgram(p.native)
 	linked := C.GLint(C.GL_FALSE)
-	C.glGetProgramiv(program, C.GL_LINK_STATUS, &linked)
+	C.glGetProgramiv(p.native, C.GL_LINK_STATUS, &linked)
 	if linked == C.GL_FALSE {
 		panic("program error")
 	}
-	return program
 }
 
-var (
-	initialized = false
-)
+var initialized = false
 
 func initialize() {
-	// TODO: when should this function be called?
-	vertexShader.id = C.glCreateShader(C.GL_VERTEX_SHADER)
-	if vertexShader.id == 0 {
-		panic("creating shader failed")
+	for _, shader := range shaders {
+		shader.compile()
 	}
-	fragmentShader.id = C.glCreateShader(C.GL_FRAGMENT_SHADER)
-	if fragmentShader.id == 0 {
-		panic("creating shader failed")
+	defer func() {
+		for _, shader := range shaders {
+			shader.delete()
 		}
-	colorMatrixShader.id = C.glCreateShader(C.GL_FRAGMENT_SHADER)
-	if colorMatrixShader.id == 0 {
-		panic("creating shader failed")
+	}()
+
+	for _, program := range programs {
+		program.create()
 	}
 
-	vertexShader.compile()
-	fragmentShader.compile()
-	colorMatrixShader.compile()
-
-	programRegular = createProgram(vertexShader, fragmentShader)
-	programColorMatrix = createProgram(vertexShader, colorMatrixShader)
-
-	C.glDeleteShader(vertexShader.id)
-	C.glDeleteShader(fragmentShader.id)
-	C.glDeleteShader(colorMatrixShader.id)
-
 	initialized = true
 }
 
@@ -105,13 +115,14 @@ func getUniformLocation(program C.GLuint, name string) C.GLint {
 
 func use(projectionMatrix [16]float32,
 	geometryMatrix matrix.Geometry, colorMatrix matrix.Color) C.GLuint {
-	program := programRegular
+	programId := programRegular
 	if !colorMatrix.IsIdentity() {
-		program = programColorMatrix
+		programId = programColorMatrix
 	}
-	C.glUseProgram(program)
+	program := programs[programId]
+	C.glUseProgram(program.native)
 
-	C.glUniformMatrix4fv(C.GLint(getUniformLocation(program, "projection_matrix")),
+	C.glUniformMatrix4fv(C.GLint(getUniformLocation(program.native, "projection_matrix")),
 		1, C.GL_FALSE, (*C.GLfloat)(&projectionMatrix[0]))
 
 	a := float32(geometryMatrix.Elements[0][0])
@@ -126,14 +137,14 @@ func use(projectionMatrix [16]float32,
 		0, 0, 1, 0,
 		tx, ty, 0, 1,
 	}
-	C.glUniformMatrix4fv(getUniformLocation(program, "modelview_matrix"),
+	C.glUniformMatrix4fv(getUniformLocation(program.native, "modelview_matrix"),
 		1, C.GL_FALSE,
 		(*C.GLfloat)(&glModelviewMatrix[0]))
 
-	C.glUniform1i(getUniformLocation(program, "texture"), 0)
+	C.glUniform1i(getUniformLocation(program.native, "texture"), 0)
 
-	if program != programColorMatrix {
-		return program
+	if programId != programColorMatrix {
+		return program.native
 	}
 
 	e := [4][5]float32{}
@@ -149,14 +160,14 @@ func use(projectionMatrix [16]float32,
 		e[0][2], e[1][2], e[2][2], e[3][2],
 		e[0][3], e[1][3], e[2][3], e[3][3],
 	}
-	C.glUniformMatrix4fv(getUniformLocation(program, "color_matrix"),
+	C.glUniformMatrix4fv(getUniformLocation(program.native, "color_matrix"),
 		1, C.GL_FALSE, (*C.GLfloat)(&glColorMatrix[0]))
 
 	glColorMatrixTranslation := [...]float32{
 		e[0][4], e[1][4], e[2][4], e[3][4],
 	}
-	C.glUniform4fv(getUniformLocation(program, "color_matrix_translation"),
+	C.glUniform4fv(getUniformLocation(program.native, "color_matrix_translation"),
 		1, (*C.GLfloat)(&glColorMatrixTranslation[0]))
 
-	return program
+	return program.native
 }

graphics/opengl/shader/shader.go

@@ -6,92 +6,113 @@ package shader
 // #include <stdlib.h>
 import "C"
 import (
+	"fmt"
 	"unsafe"
 )
 
 type shader struct {
-	id     C.GLuint
-	name   string
+	native     C.GLuint
+	shaderType C.GLenum
 	source     string
 }
 
-var (
-	vertexShader = &shader{
-		id:   0,
-		name: "vertex_shader",
+type shaderId int
+
+const (
+	shaderVertex shaderId = iota
+	shaderFragment
+	shaderColorMatrix
+	shaderSolidColor
+)
+
+var shaders = map[shaderId]*shader{
+	shaderVertex: &shader{
+		shaderType: C.GL_VERTEX_SHADER,
 		source: `
-attribute /*highp*/ vec2 vertex;
-attribute /*highp*/ vec2 texture;
-uniform /*highp*/ mat4 projection_matrix;
-uniform /*highp*/ mat4 modelview_matrix;
-varying /*highp*/ vec2 tex_coord;
+attribute vec2 vertex;
+attribute vec2 texture;
+uniform mat4 projection_matrix;
+uniform mat4 modelview_matrix;
+varying vec2 tex_coord;
 
 void main(void) {
   tex_coord = texture;
   gl_Position = projection_matrix * modelview_matrix * vec4(vertex, 0, 1);
 }
 `,
-	}
-	fragmentShader = &shader{
-		id:   0,
-		name: "fragment_shader",
+	},
+	shaderFragment: &shader{
+		shaderType: C.GL_FRAGMENT_SHADER,
 		source: `
-uniform /*lowp*/ sampler2D texture;
-varying /*highp*/ vec2 tex_coord;
+uniform sampler2D texture;
+varying vec2 tex_coord;
 
 void main(void) {
   gl_FragColor = texture2D(texture, tex_coord);
 }
 `,
-	}
-	colorMatrixShader = &shader{
-		id:   0,
-		name: "color_matrix_shader",
+	},
+	shaderColorMatrix: &shader{
+		shaderType: C.GL_FRAGMENT_SHADER,
 		source: `
-uniform /*highp*/ sampler2D texture;
-uniform /*lowp*/ mat4 color_matrix;
-uniform /*lowp*/ vec4 color_matrix_translation;
-varying /*highp*/ vec2 tex_coord;
+uniform sampler2D texture;
+uniform mat4 color_matrix;
+uniform vec4 color_matrix_translation;
+varying vec2 tex_coord;
 
 void main(void) {
-  /*lowp*/ vec4 color = texture2D(texture, tex_coord);
+  vec4 color = texture2D(texture, tex_coord);
   gl_FragColor = (color_matrix * color) + color_matrix_translation;
 }
 `,
-	}
-)
+	},
+	shaderSolidColor: &shader{
+		shaderType: C.GL_FRAGMENT_SHADER,
+		source: `
+uniform vec4 color;
 
-var (
-	programRegular     = C.GLuint(0)
-	programColorMatrix = C.GLuint(0)
-)
+void main(void) {
+  gl_FragColor = color;
+}
+`,
+	},
+}
 
 func (s *shader) compile() {
+	s.native = C.glCreateShader(s.shaderType)
+	if s.native == 0 {
+		panic("glCreateShader failed")
+	}
+
 	csource := (*C.GLchar)(C.CString(s.source))
 	// TODO: defer?
 	// defer C.free(unsafe.Pointer(csource))
 
-	C.glShaderSource(s.id, 1, &csource, nil)
-	C.glCompileShader(s.id)
+	C.glShaderSource(s.native, 1, &csource, nil)
+	C.glCompileShader(s.native)
 
 	compiled := C.GLint(C.GL_FALSE)
-	C.glGetShaderiv(s.id, C.GL_COMPILE_STATUS, &compiled)
+	C.glGetShaderiv(s.native, C.GL_COMPILE_STATUS, &compiled)
 	if compiled == C.GL_FALSE {
 		s.showShaderLog()
-		panic("shader compile failed: " + s.name)
+		panic("shader compile failed")
 	}
 }
 
 func (s *shader) showShaderLog() {
 	logSize := C.GLint(0)
-	C.glGetShaderiv(s.id, C.GL_INFO_LOG_LENGTH, &logSize)
+	C.glGetShaderiv(s.native, C.GL_INFO_LOG_LENGTH, &logSize)
 	if logSize == 0 {
 		return
 	}
 	length := C.GLsizei(0)
 	buffer := make([]C.GLchar, logSize)
-	C.glGetShaderInfoLog(s.id, C.GLsizei(logSize), &length, &buffer[0])
+	C.glGetShaderInfoLog(s.native, C.GLsizei(logSize), &length, &buffer[0])
 
 	message := string(C.GoBytes(unsafe.Pointer(&buffer[0]), C.int(length)))
-	print("shader error (", s.name, "):\n", message)
+	fmt.Printf("shader error: %s\n", message)
+}
+
+func (s *shader) delete() {
+	C.glDeleteShader(s.native)
 }

ui/cocoa/window_events.go

@@ -60,4 +60,3 @@ func (w *windowEvents) notifyWindowClosed(e ui.WindowClosedEvent) {
 		w.windowClosed <- e
 	}()
 }
-