Move drawing function to shader package

graphics/opengl/context.go

@@ -14,7 +14,6 @@ import (
 	"github.com/hajimehoshi/go-ebiten/graphics/texture"
 	"image"
 	"math"
-	"unsafe"
 )
 
 type Context struct {
@@ -57,7 +56,7 @@ func (context *Context) Init() {
 		panic("creating main framebuffer failed: " + err.Error())
 	}
 
-	shader.Initialize()
+	shader.Init()
 
 	context.screenId, err = context.NewRenderTarget(
 		context.screenWidth, context.screenHeight)
@@ -85,68 +84,13 @@ func (context *Context) Fill(r, g, b uint8) {
 }
 
 type TextureDrawing struct {
-	context        *Context
+	projectionMatrix [16]float32
 	geometryMatrix   matrix.Geometry
 	colorMatrix      matrix.Color
 }
 
 func (t *TextureDrawing) Draw(native interface{}, quads []texture.Quad) {
-	if len(quads) == 0 {
+	shader.DrawTexture(uint(native.(C.GLuint)), t.projectionMatrix, quads, t.geometryMatrix, t.colorMatrix)
-		return
-	}
-	shaderProgram := t.context.setShaderProgram(t.geometryMatrix, t.colorMatrix)
-	C.glBindTexture(C.GL_TEXTURE_2D, native.(C.GLuint))
-
-	vertexAttrLocation := shader.GetAttributeLocation(shaderProgram, "vertex")
-	textureAttrLocation := shader.GetAttributeLocation(shaderProgram, "texture")
-
-	C.glEnableClientState(C.GL_VERTEX_ARRAY)
-	C.glEnableClientState(C.GL_TEXTURE_COORD_ARRAY)
-	C.glEnableVertexAttribArray(C.GLuint(vertexAttrLocation))
-	C.glEnableVertexAttribArray(C.GLuint(textureAttrLocation))
-	vertices := []float32{}
-	texCoords := []float32{}
-	indicies := []uint32{}
-	// TODO: Check len(parts) and GL_MAX_ELEMENTS_INDICES
-	for i, quad := range quads {
-		x1 := quad.VertexX1
-		x2 := quad.VertexX2
-		y1 := quad.VertexY1
-		y2 := quad.VertexY2
-		vertices = append(vertices,
-			x1, y1,
-			x2, y1,
-			x1, y2,
-			x2, y2,
-		)
-		u1 := quad.TextureCoordU1
-		u2 := quad.TextureCoordU2
-		v1 := quad.TextureCoordV1
-		v2 := quad.TextureCoordV2
-		texCoords = append(texCoords,
-			u1, v1,
-			u2, v1,
-			u1, v2,
-			u2, v2,
-		)
-		base := uint32(i * 4)
-		indicies = append(indicies,
-			base, base+1, base+2,
-			base+1, base+2, base+3,
-		)
-	}
-	C.glVertexAttribPointer(C.GLuint(vertexAttrLocation), 2,
-		C.GL_FLOAT, C.GL_FALSE,
-		0, unsafe.Pointer(&vertices[0]))
-	C.glVertexAttribPointer(C.GLuint(textureAttrLocation), 2,
-		C.GL_FLOAT, C.GL_FALSE,
-		0, unsafe.Pointer(&texCoords[0]))
-	C.glDrawElements(C.GL_TRIANGLES, C.GLsizei(len(indicies)),
-		C.GL_UNSIGNED_INT, unsafe.Pointer(&indicies[0]))
-	C.glDisableVertexAttribArray(C.GLuint(textureAttrLocation))
-	C.glDisableVertexAttribArray(C.GLuint(vertexAttrLocation))
-	C.glDisableClientState(C.GL_TEXTURE_COORD_ARRAY)
-	C.glDisableClientState(C.GL_VERTEX_ARRAY)
 }
 
 func (context *Context) DrawTexture(
@@ -156,7 +100,7 @@ func (context *Context) DrawTexture(
 	if !ok {
 		panic("invalid texture ID")
 	}
-	drawing := &TextureDrawing{context, geometryMatrix, colorMatrix}
+	drawing := &TextureDrawing{context.projectionMatrix, geometryMatrix, colorMatrix}
 	texture.Draw(drawing.Draw)
 }
 
@@ -167,7 +111,7 @@ func (context *Context) DrawTextureParts(
 	if !ok {
 		panic("invalid texture ID")
 	}
-	drawing := &TextureDrawing{context, geometryMatrix, colorMatrix}
+	drawing := &TextureDrawing{context.projectionMatrix, geometryMatrix, colorMatrix}
 	texture.DrawParts(parts, drawing.Draw)
 }
 
@@ -238,11 +182,6 @@ func (context *Context) flush() {
 	C.glFlush()
 }
 
-func (context *Context) setShaderProgram(
-	geometryMatrix matrix.Geometry, colorMatrix matrix.Color) (program shader.Program) {
-	return shader.Use(context.projectionMatrix, geometryMatrix, colorMatrix)
-}
-
 func (context *Context) NewRenderTarget(width, height int) (
 	graphics.RenderTargetId, error) {
 	renderTarget, err := newRenderTarget(width, height)

graphics/opengl/shader/shader.go

@@ -7,16 +7,10 @@ package shader
 import "C"
 import (
 	"github.com/hajimehoshi/go-ebiten/graphics/matrix"
+	"github.com/hajimehoshi/go-ebiten/graphics/texture"
 	"unsafe"
 )
 
-type Program int
-
-const (
-	ProgramRegular Program = iota
-	ProgramColorMatrix
-)
-
 type Location int
 
 type shader struct {
@@ -72,8 +66,8 @@ void main(void) {
 )
 
 var (
-	regularShaderProgram     = C.GLuint(0)
+	programRegular     = C.GLuint(0)
-	colorMatrixShaderProgram = C.GLuint(0)
+	programColorMatrix = C.GLuint(0)
 )
 
 func (s *shader) compile() {
@@ -120,7 +114,7 @@ func createProgram(shaders ...*shader) C.GLuint {
 	return program
 }
 
-func Initialize() {
+func Init() {
 	// TODO: when should this function be called?
 	vertexShader.id = C.glCreateShader(C.GL_VERTEX_SHADER)
 	if vertexShader.id == 0 {
@@ -139,8 +133,8 @@ func Initialize() {
 	fragmentShader.compile()
 	colorMatrixShader.compile()
 
-	regularShaderProgram = createProgram(vertexShader, fragmentShader)
+	programRegular = createProgram(vertexShader, fragmentShader)
-	colorMatrixShaderProgram = createProgram(vertexShader, colorMatrixShader)
+	programColorMatrix = createProgram(vertexShader, colorMatrixShader)
 
 	C.glDeleteShader(vertexShader.id)
 	C.glDeleteShader(fragmentShader.id)
@@ -159,34 +153,21 @@ var (
 	}
 )
 
-func toInnerProgram(program Program) C.GLuint {
+func getLocation(program C.GLuint, name string, qualifierVariableType int) C.GLint {
-	switch program {
-	case ProgramRegular:
-		return regularShaderProgram
-	case ProgramColorMatrix:
-		return colorMatrixShaderProgram
-	default:
-		panic("no reach")
-	}
-	return C.GLuint(0)
-}
-
-func getLocation(program Program, name string, qualifierVariableType int) int {
 	if location, ok := shaderLocationCache[qualifierVariableType][name]; ok {
-		return int(location)
+		return location
 	}
 
 	locationName := C.CString(name)
 	defer C.free(unsafe.Pointer(locationName))
 
 	location := C.GLint(-1)
-	innerProgram := toInnerProgram(program)
 	
 	switch qualifierVariableType {
 	case qualifierVariableTypeAttribute:
-		location = C.glGetAttribLocation(innerProgram, (*C.GLchar)(locationName))
+		location = C.glGetAttribLocation(program, (*C.GLchar)(locationName))
 	case qualifierVariableTypeUniform:
-		location = C.glGetUniformLocation(innerProgram, (*C.GLchar)(locationName))
+		location = C.glGetUniformLocation(program, (*C.GLchar)(locationName))
 	default:
 		panic("no reach")
 	}
@@ -195,23 +176,23 @@ func getLocation(program Program, name string, qualifierVariableType int) int {
 	}
 	shaderLocationCache[qualifierVariableType][name] = location
 
-	return int(location)
+	return location
 }
 
-func GetAttributeLocation(program Program, name string) int {
+func getAttributeLocation(program C.GLuint, name string) C.GLint {
 	return getLocation(program, name, qualifierVariableTypeAttribute)
 }
 
-func getUniformLocation(program Program, name string) int {
+func getUniformLocation(program C.GLuint, name string) C.GLint {
 	return getLocation(program, name, qualifierVariableTypeUniform)
 }
 
-func Use(projectionMatrix [16]float32, geometryMatrix matrix.Geometry, colorMatrix matrix.Color) Program {
+func use(projectionMatrix [16]float32, geometryMatrix matrix.Geometry, colorMatrix matrix.Color) C.GLuint {
-	program := ProgramRegular
+	program := programRegular
 	if !colorMatrix.IsIdentity() {
-		program = ProgramColorMatrix
+		program = programColorMatrix
 	}
-	C.glUseProgram(toInnerProgram(program))
+	C.glUseProgram(program)
 	
 	C.glUniformMatrix4fv(C.GLint(getUniformLocation(program, "projection_matrix")),
 		1, C.GL_FALSE, (*C.GLfloat)(&projectionMatrix[0]))
@@ -228,13 +209,13 @@ func Use(projectionMatrix [16]float32, geometryMatrix matrix.Geometry, colorMatr
 		0, 0, 1, 0,
 		tx, ty, 0, 1,
 	}
-	C.glUniformMatrix4fv(C.GLint(getUniformLocation(program, "modelview_matrix")),
+	C.glUniformMatrix4fv(getUniformLocation(program, "modelview_matrix"),
 		1, C.GL_FALSE,
 		(*C.GLfloat)(&glModelviewMatrix[0]))
 
-	C.glUniform1i(C.GLint(getUniformLocation(program, "texture")), 0)
+	C.glUniform1i(getUniformLocation(program, "texture"), 0)
 
-	if program != ProgramColorMatrix {
+	if program != programColorMatrix {
 		return program
 	}
 
@@ -251,14 +232,74 @@ func Use(projectionMatrix [16]float32, geometryMatrix matrix.Geometry, colorMatr
 		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(C.GLint(getUniformLocation(program, "color_matrix")),
+	C.glUniformMatrix4fv(getUniformLocation(program, "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(C.GLint(getUniformLocation(program, "color_matrix_translation")),
+	C.glUniform4fv(getUniformLocation(program, "color_matrix_translation"),
 		1, (*C.GLfloat)(&glColorMatrixTranslation[0]))
 
 	return program
 }
+
+func DrawTexture(native uint, projectionMatrix [16]float32, quads []texture.Quad,
+	geometryMatrix matrix.Geometry, colorMatrix matrix.Color) {
+	if len(quads) == 0 {
+		return
+	}
+	shaderProgram := use(projectionMatrix, geometryMatrix, colorMatrix)
+	C.glBindTexture(C.GL_TEXTURE_2D, C.GLuint(native))
+
+	vertexAttrLocation := getAttributeLocation(shaderProgram, "vertex")
+	textureAttrLocation := getAttributeLocation(shaderProgram, "texture")
+
+	C.glEnableClientState(C.GL_VERTEX_ARRAY)
+	C.glEnableClientState(C.GL_TEXTURE_COORD_ARRAY)
+	C.glEnableVertexAttribArray(C.GLuint(vertexAttrLocation))
+	C.glEnableVertexAttribArray(C.GLuint(textureAttrLocation))
+	vertices := []float32{}
+	texCoords := []float32{}
+	indicies := []uint32{}
+	// TODO: Check len(parts) and GL_MAX_ELEMENTS_INDICES
+	for i, quad := range quads {
+		x1 := quad.VertexX1
+		x2 := quad.VertexX2
+		y1 := quad.VertexY1
+		y2 := quad.VertexY2
+		vertices = append(vertices,
+			x1, y1,
+			x2, y1,
+			x1, y2,
+			x2, y2,
+		)
+		u1 := quad.TextureCoordU1
+		u2 := quad.TextureCoordU2
+		v1 := quad.TextureCoordV1
+		v2 := quad.TextureCoordV2
+		texCoords = append(texCoords,
+			u1, v1,
+			u2, v1,
+			u1, v2,
+			u2, v2,
+		)
+		base := uint32(i * 4)
+		indicies = append(indicies,
+			base, base+1, base+2,
+			base+1, base+2, base+3,
+		)
+	}
+	C.glVertexAttribPointer(C.GLuint(vertexAttrLocation), 2,
+		C.GL_FLOAT, C.GL_FALSE,
+		0, unsafe.Pointer(&vertices[0]))
+	C.glVertexAttribPointer(C.GLuint(textureAttrLocation), 2,
+		C.GL_FLOAT, C.GL_FALSE,
+		0, unsafe.Pointer(&texCoords[0]))
+	C.glDrawElements(C.GL_TRIANGLES, C.GLsizei(len(indicies)),
+		C.GL_UNSIGNED_INT, unsafe.Pointer(&indicies[0]))
+	C.glDisableVertexAttribArray(C.GLuint(textureAttrLocation))
+	C.glDisableVertexAttribArray(C.GLuint(vertexAttrLocation))
+	C.glDisableClientState(C.GL_TEXTURE_COORD_ARRAY)
+	C.glDisableClientState(C.GL_VERTEX_ARRAY)
+}