lloeki/ld48-29
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correct sprite scale and AR

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This commit is contained in:
Loic Nageleisen 2014-04-26 16:10:38 +02:00
parent 98ebd8cfda
commit b020667b00
2 changed files with 36 additions and 11 deletions
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43
ld48-29.go
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@ -98,30 +98,49 @@ func readTexture(r io.Reader) (texId gl.Texture, err error) {
}
func spriteQuad(x int, y int, w int, h int) {
size := 256
unit := 16
scaledSpriteQuad(x, y, w, h, 1.0)
}
x1 := x * unit
y1 := y * unit
func scaledSpriteQuad(x int, y int, w int, h int, scale float32) {
// TODO: set elsewhere (spritesheet property)
size := 256 // spritesheet size
unit := 16 // sprite unit size
// sprite to absolute pixel coords
// origin is as tex: bottom-left
x1 := x * unit
y1 := y * unit
x2 := x1 + w * unit
y2 := y1 + h * unit
// abs pixel to relative tex coords
rx1 := float32(x1) / float32(size)
rx2 := float32(x2) / float32(size)
ry1 := float32(y1) / float32(size)
ry2 := float32(y2) / float32(size)
// scale sprite
qsize := 1.0 * scale
// relative model coords
// sprite-centered origin
qx1 := -qsize * float32(w) / 2.0
qy1 := -qsize * float32(h) / 2.0
qx2 := qsize * float32(w) / 2.0
qy2 := qsize * float32(h) / 2.0
// draw sprite quad
gl.MatrixMode(gl.MODELVIEW)
gl.Begin(gl.QUADS)
gl.Normal3f(0, 0, 1)
gl.TexCoord2f(rx1, ry1)
gl.Vertex3f(-1.0, -1.0, 1.0)
gl.Vertex3f(qx1, qy1, 1.0)
gl.TexCoord2f(rx2, ry1)
gl.Vertex3f(1.0, -1.0, 1.0)
gl.Vertex3f(qx2, qy1, 1.0)
gl.TexCoord2f(rx2, ry2)
gl.Vertex3f(1.0, 1.0, 1.0)
gl.Vertex3f(qx2, qy2, 1.0)
gl.TexCoord2f(rx1, ry2)
gl.Vertex3f(-1.0, 1.0, 1.0)
gl.Vertex3f(qx1, qy2, 1.0)
gl.End()
}
@ -182,7 +201,7 @@ func setup() (textures map[string]gl.Texture, lists map[string]uint) {
quad := gl.GenLists(1)
gl.NewList(quad, gl.COMPILE)
spriteQuad(0, 0, 4, 4)
spriteQuad(0, 0, 2, 2)
gl.EndList()
lists["test"] = quad
@ -197,13 +216,16 @@ func destroy(textures map[string]gl.Texture) {
}
func render(textures map[string]gl.Texture, lists map[string]uint) {
// start afresh
gl.Clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT)
gl.MatrixMode(gl.PROJECTION)
// set viewport
gl.MatrixMode(gl.PROJECTION)
gl.LoadIdentity()
gl.Frustum(-1, 1, -1, 1, 1.0, 10.0)
gl.Translatef(0, 0, -3.0)
// lighten things
ambient := []float32{0.5, 0.5, 0.5, 1}
diffuse := []float32{1, 1, 1, 1}
lightpos := []float32{-5, 5, 10, 0}
@ -213,6 +235,5 @@ func render(textures map[string]gl.Texture, lists map[string]uint) {
gl.Enable(gl.LIGHT0)
textures["sprites"].Bind(gl.TEXTURE_2D)
gl.Color4f(1, 1, 1, 1)
gl.CallList(lists["test"])
}