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Add screen->world and world->screen functions for 2D; add extended camera2D example (#947)

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arvyy 2019-08-27 14:05:28 +03:00 • committed by Ray
parent 37bb8e9554
commit 97101d1003
3 changed files with 324 additions and 22 deletions
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59
src/core.c
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@ -1250,28 +1250,7 @@ void BeginMode2D(Camera2D camera)
rlLoadIdentity(); // Reset current matrix (MODELVIEW)
rlMultMatrixf(MatrixToFloat(screenScaling)); // Apply screen scaling if required
// The camera in world-space is set by
// 1. Move it to target
// 2. Rotate by -rotation and scale by (1/zoom)
// When setting higher scale, it's more intuitive for the world to become bigger (= camera become smaller),
// not for the camera getting bigger, hence the invert. Same deal with rotation.
// 3. Move it by (-offset);
// Offset defines target transform relative to screen, but since we're effectively "moving" screen (camera)
// we need to do it into opposite direction (inverse transform)
// Having camera transform in world-space, inverse of it gives the modelview transform.
// Since (A*B*C)' = C'*B'*A', the modelview is
// 1. Move to offset
// 2. Rotate and Scale
// 3. Move by -target
Matrix matOrigin = MatrixTranslate(-camera.target.x, -camera.target.y, 0.0f);
Matrix matRotation = MatrixRotate((Vector3){ 0.0f, 0.0f, 1.0f }, camera.rotation*DEG2RAD);
Matrix matScale = MatrixScale(camera.zoom, camera.zoom, 1.0f);
Matrix matTranslation = MatrixTranslate(camera.offset.x, camera.offset.y, 0.0f);
Matrix matTransform = MatrixMultiply(MatrixMultiply(matOrigin, MatrixMultiply(matScale, matRotation)), matTranslation);
rlMultMatrixf(MatrixToFloat(matTransform)); // Apply transformation to modelview
rlMultMatrixf(MatrixToFloat(GetCamera2DMatrix(camera))); // Apply transformation to modelview
}
// Ends 2D mode with custom camera
@ -1502,6 +1481,42 @@ Matrix GetCameraMatrix(Camera camera)
return MatrixLookAt(camera.position, camera.target, camera.up);
}
Vector2 GetScreenToWorld2D(Vector2 position, Camera2D camera) {
Matrix m = MatrixInvert(GetCamera2DMatrix(camera));
Vector3 transform = Vector3Transform((Vector3){position.x, position.y, 0}, m);
return (Vector2){transform.x, transform.y};
}
Vector2 GetWorldToScreen2D(Vector2 position, Camera2D camera) {
Matrix m = GetCamera2DMatrix(camera);
Vector3 transform = Vector3Transform((Vector3){position.x, position.y, 0}, m);
return (Vector2){transform.x, transform.y};
}
Matrix GetCamera2DMatrix(Camera2D camera) {
// The camera in world-space is set by
// 1. Move it to target
// 2. Rotate by -rotation and scale by (1/zoom)
// When setting higher scale, it's more intuitive for the world to become bigger (= camera become smaller),
// not for the camera getting bigger, hence the invert. Same deal with rotation.
// 3. Move it by (-offset);
// Offset defines target transform relative to screen, but since we're effectively "moving" screen (camera)
// we need to do it into opposite direction (inverse transform)
// Having camera transform in world-space, inverse of it gives the modelview transform.
// Since (A*B*C)' = C'*B'*A', the modelview is
// 1. Move to offset
// 2. Rotate and Scale
// 3. Move by -target
Matrix matOrigin = MatrixTranslate(-camera.target.x, -camera.target.y, 0.0f);
Matrix matRotation = MatrixRotate((Vector3){ 0.0f, 0.0f, 1.0f }, camera.rotation*DEG2RAD);
Matrix matScale = MatrixScale(camera.zoom, camera.zoom, 1.0f);
Matrix matTranslation = MatrixTranslate(camera.offset.x, camera.offset.y, 0.0f);
Matrix matTransform = MatrixMultiply(MatrixMultiply(matOrigin, MatrixMultiply(matScale, matRotation)), matTranslation);
return matTransform;
}
// Set target FPS (maximum)
void SetTargetFPS(int fps)
{