graphics: Add geometry matrix info to vertices

imageimpl.go

@@ -128,7 +128,7 @@ func (i *imageImpl) DrawImage(image *Image, options *DrawImageOptions) error {
 		}
 	}
 	w, h := image.impl.restorable.Size()
-	vs := vertices(parts, w, h)
+	vs := vertices(parts, w, h, &options.GeoM)
 	if len(vs) == 0 {
 		return nil
 	}

imageparts.go

@@ -77,7 +77,8 @@ func v(y, height2p int) int16 {
 	return int16(math.MaxInt16 * y / height2p)
 }
 
-func vertices(parts ImageParts, width, height int) []uint8 {
+func vertices(parts ImageParts, width, height int, geo *GeoM) []uint8 {
+	// TODO: This function should be in graphics package?
 	totalSize := graphics.QuadVertexSizeInBytes()
 	oneSize := totalSize / 4
 	l := parts.Len()
@@ -86,6 +87,12 @@ func vertices(parts ImageParts, width, height int) []uint8 {
 	height2p := graphics.NextPowerOf2Int(height)
 	n := 0
 	vs := make([]int16, 16)
+	geoBytes := floatBytes(geo.Element(0, 0),
+		geo.Element(0, 1),
+		geo.Element(1, 0),
+		geo.Element(1, 1),
+		geo.Element(0, 2),
+		geo.Element(1, 2))
 	for i := 0; i < l; i++ {
 		dx0, dy0, dx1, dy1 := parts.Dst(i)
 		if dx0 == dx1 || dy0 == dy1 {
@@ -114,15 +121,21 @@ func vertices(parts ImageParts, width, height int) []uint8 {
 		vs[14] = u1
 		vs[15] = v1
 		// Use direct assign here. `append` function might be slow on browsers.
+		for j := 0; j < 4; j++ {
+			offset := totalSize*n + oneSize*j
 			if endian.IsLittle() {
-			for i, v := range vs {
+				for k, v := range vs[4*j : 4*j+4] {
-				vertices[totalSize*n+oneSize*(i/4)+2*(i%4)] = uint8(v)
+					vertices[offset+2*k] = uint8(v)
-				vertices[totalSize*n+oneSize*(i/4)+2*(i%4)+1] = uint8(v >> 8)
+					vertices[offset+2*k+1] = uint8(v >> 8)
 				}
 			} else {
-			for i, v := range vs {
+				for k, v := range vs[4*j : 4*j+4] {
-				vertices[totalSize*n+oneSize*(i/4)+2*(i%4)] = uint8(v >> 8)
+					vertices[offset+2*k] = uint8(v >> 8)
-				vertices[totalSize*n+oneSize*(i/4)+2*(i%4)+1] = uint8(v)
+					vertices[offset+2*k+1] = uint8(v)
+				}
+			}
+			for k, g := range geoBytes {
+				vertices[offset+8+k] = g
 			}
 		}
 		n++

internal/graphics/program.go

@@ -65,6 +65,7 @@ func (a *arrayBufferLayout) disable(c *opengl.Context, program opengl.Program) {
 
 var (
 	theArrayBufferLayout = arrayBufferLayout{
+		// Note that GL_MAX_VERTEX_ATTRIBS is at least 16.
 		parts: []arrayBufferLayoutPart{
 			{
 				name:      "vertex",
@@ -78,6 +79,18 @@ var (
 				num:       2,
 				normalize: true,
 			},
+			{
+				name:      "geo_matrix",
+				dataType:  opengl.Float,
+				num:       4,
+				normalize: false,
+			},
+			{
+				name:      "geo_matrix_translation",
+				dataType:  opengl.Float,
+				num:       2,
+				normalize: false,
+			},
 		},
 	}
 )

internal/graphics/shader.go

@@ -39,14 +39,23 @@ func shader(c *opengl.Context, id shaderId) string {
 var shaders = map[shaderId]string{
 	shaderVertexModelview: `
 uniform highp mat4 projection_matrix;
-uniform highp mat4 modelview_matrix;
+uniform highp mat4 modelview_matrix; // TODO: Remove this
 attribute highp vec2 vertex;
 attribute highp vec2 tex_coord;
+attribute highp vec4 geo_matrix;
+attribute highp vec2 geo_matrix_translation;
 varying highp vec2 vertex_out_tex_coord;
 
 void main(void) {
   vertex_out_tex_coord = tex_coord;
-  gl_Position = projection_matrix * modelview_matrix * vec4(vertex, 0, 1);
+  mat4 x = modelview_matrix; // temporary hack not to omit modelview_matrix
+  mat4 geom = mat4(
+    vec4(geo_matrix[0], geo_matrix[2], 0, 0),
+    vec4(geo_matrix[1], geo_matrix[3], 0, 0),
+    vec4(0, 0, 1, 0),
+    vec4(geo_matrix_translation, 0, 1)
+  );
+  gl_Position = projection_matrix * geom * vec4(vertex, 0, 1);
 }
 `,
 	shaderFragmentTexture: `

math.go

@@ -0,0 +1,45 @@
+// Copyright 2016 The Ebiten Authors
+//
+// 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.
+
+// +build !js
+
+package ebiten
+
+import (
+	"unsafe"
+
+	"github.com/hajimehoshi/ebiten/internal/endian"
+)
+
+func floatBytes(xs ...float64) []uint8 {
+	bits := make([]uint8, 0, len(xs)*4)
+	for _, x := range xs {
+		x32 := float32(x)
+		n := *(*uint32)(unsafe.Pointer(&x32))
+		if endian.IsLittle() {
+			bits = append(bits,
+				uint8(n),
+				uint8(n>>8),
+				uint8(n>>16),
+				uint8(n>>24))
+		} else {
+			bits = append(bits,
+				uint8(n>>24),
+				uint8(n>>16),
+				uint8(n>>8),
+				uint8(n))
+		}
+	}
+	return bits
+}

math_js.go

@@ -0,0 +1,31 @@
+// Copyright 2016 The Ebiten Authors
+//
+// 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.
+
+// +build js
+
+package ebiten
+
+import (
+	"github.com/gopherjs/gopherjs/js"
+)
+
+func floatBytes(xs ...float64) []uint8 {
+	a := js.Global.Get("ArrayBuffer").New(4 * len(xs))
+	af32 := js.Global.Get("Float32Array").New(a)
+	a8 := js.Global.Get("Uint8Array").New(a)
+	for i, x := range xs {
+		af32.SetIndex(i, x)
+	}
+	return a8.Interface().([]uint8)
+}