Merge pull request #453 from emersion/surface-transform

Add surface transforms support

1 files changed, 28 insertions, 11 deletions

diff --git a/render/matrix.c b/render/matrix.c
index e49d365e..54dba4cc 100644
--- a/render/matrix.c
+++ b/render/matrix.c
@@ -86,38 +86,55 @@ void wlr_matrix_mul(const float (*x)[16], const float (*y)[16], float (*product)
 static const float transforms[][4] = {
 	[WL_OUTPUT_TRANSFORM_NORMAL] = {
 		1.0f, 0.0f,
-		0.0f, -1.0f,
+		0.0f, 1.0f,
 	},
 	[WL_OUTPUT_TRANSFORM_90] = {
 		0.0f, -1.0f,
-		-1.0f, 0.0f,
+		1.0f, 0.0f,
 	},
 	[WL_OUTPUT_TRANSFORM_180] = {
 		-1.0f, 0.0f,
-		0.0f, 1.0f,
+		0.0f, -1.0f,
 	},
 	[WL_OUTPUT_TRANSFORM_270] = {
 		0.0f, 1.0f,
-		1.0f, 0.0f,
+		-1.0f, 0.0f,
 	},
 	[WL_OUTPUT_TRANSFORM_FLIPPED] = {
 		-1.0f, 0.0f,
-		0.0f, -1.0f,
+		0.0f, 1.0f,
 	},
 	[WL_OUTPUT_TRANSFORM_FLIPPED_90] = {
-		0.0f, 1.0f,
+		0.0f, -1.0f,
 		-1.0f, 0.0f,
 	},
 	[WL_OUTPUT_TRANSFORM_FLIPPED_180] = {
 		1.0f, 0.0f,
-		0.0f, 1.0f,
+		0.0f, -1.0f,
 	},
 	[WL_OUTPUT_TRANSFORM_FLIPPED_270] = {
-		0.0f, -1.0f,
+		0.0f, 1.0f,
 		1.0f, 0.0f,
 	},
 };
 
+void wlr_matrix_transform(float mat[static 16],
+		enum wl_output_transform transform) {
+	memset(mat, 0, sizeof(*mat) * 16);
+
+	const float *t = transforms[transform];
+
+	// Rotation + reflection
+	mat[0] = t[0];
+	mat[1] = t[1];
+	mat[4] = t[2];
+	mat[5] = t[3];
+
+	// Identity
+	mat[10] = 1.0f;
+	mat[15] = 1.0f;
+}
+
 // Equivilent to glOrtho(0, width, 0, height, 1, -1) with the transform applied
 void wlr_matrix_texture(float mat[static 16], int32_t width, int32_t height,
 		enum wl_output_transform transform) {
@@ -127,11 +144,11 @@ void wlr_matrix_texture(float mat[static 16], int32_t width, int32_t height,
 	float x = 2.0f / width;
 	float y = 2.0f / height;
 
-	// Rotation + relection
+	// Rotation + reflection
 	mat[0] = x * t[0];
 	mat[1] = x * t[1];
-	mat[4] = y * t[2];
-	mat[5] = y * t[3];
+	mat[4] = y * -t[2];
+	mat[5] = y * -t[3];
 
 	// Translation
 	mat[3] = -copysign(1.0f, mat[0] + mat[1]);